MAN Nutzfahrzeuge Aktiengesellschaft

Service Information
Date Issued by Number: 3438PE
01/09/2010 SASIC Product development: EDC 7 with Common Rail injection system

Overview of the EDC 7 The Common Rail injection system combined with the EDC 7 control units from
control units and the Bosch have been fitted as standard across all MAN Nutzfahrzeuge series since
Common Rail injection 2002 in trucks, buses/coaches and bus/coach chassis.
system
In recent years, the EDC 7 control units and the Common Rail injection system
Notes on repair have been enhanced continuously, in order to comply with the requirements of
the legislator and the customers with regard to environmental compatibility,
fuel consumption, emissions and noise performance.
This SI offers an overview of the EDC models and descriptions of the new
functions of the various software versions, comparisons of hardware/software
and repair information.

Yours faithfully,
MAN Nutzfahrzeuge Aktiengesellschaft

ppa. G. Ziegler i.V. W. Kuchler

This SI will be updated online.

You will find the latest version of this SI on the intranet/extranet
(in the SI section as usual).
This SI replaces the following SI, see Page 2
Distribution of this SI to the worldwide service organisation
Forwarding within the organisation of the MAN service workshop:
Workshop management Yes Personnel in spare parts store Yes
Workshop personnel for performance of the work Yes Emergency service mechanics No
Workshop personnel in general Yes Customers' workshops authorised for servicing No
3438PEen
Page 1 of 157
The service information sheets listed below were incorporated in this SI product development (PE):

Service Information dated Incorporated in Section

3308AT 05.06.2009 6.1
2705AT --- 6.1

3438PEen
Page 2 of 157
Table of contents

Table of contents..............................................................................................................................................3

Modification index ............................................................................................................................................5

1 Review ................................................................................................................................................6

2 Short descriptions ............................................................................................................................6

2.1 Common Rail injection system:...........................................................................................................6
2.2 EDC 7 control unit for the Common Rail injection system ..................................................................9
2.3 Basic functions of the control unit: ......................................................................................................9
2.3.1 Setpoint formation for fuel volumes ..................................................................................................10
2.3.2 Injection start control .........................................................................................................................11
2.3.3 Fuel metering ....................................................................................................................................11
2.3.4 Fuel pressure control ........................................................................................................................11
2.3.5 Adaptive individual cylinder torque control (smooth running control) ...............................................11
2.3.6 Air system, exhaust gas aftertreatment ............................................................................................12
2.3.6.1 Charging pressure governing system ...............................................................................................12
2.3.6.2 Exhaust gas recirculation (EGR).......................................................................................................13
2.3.6.3 Engine protection functions...............................................................................................................15
2.4 Additional functions ...........................................................................................................................16
2.5 Schematic diagrams of the signal processing in the EDC 7 systems...............................................16
2.5.1 Schematic diagram of signal processing in
D08 Common Rail EuroIV engine with PM catalytic converter.........................................................17
2.5.2 Schematic diagram of signal processing in
D20 Common Rail EuroIV engine with PM catalytic converter.........................................................18
2.5.3 Schematic diagram of signal processing in D08 Common Rail EuroIV/EEV
engine with NOx check measurement and CRT particulate filter .....................................................19
2.5.4 Schematic diagram of EDC signal processing in D20, D26 Common Rail EuroV
engines with NOx check measurement, MAN AdBlue and SCR catalytic converter........................20
2.5.5 Schematic diagram of MAN AdBlue signal processing in D20 Common Rail EuroV
engine with NOx check measurement, MAN AdBlue and SCR catalytic converter..........................21
2.6 Data exchange with other control units (CAN data-bus architecture)...............................................22
3 Component description/operation ................................................................................................25
3.1 Control unit ........................................................................................................................................25
3.2 Rail ....................................................................................................................................................26
3.3 Injector...............................................................................................................................................28
3.4 High-pressure pump..........................................................................................................................31
3.4.1 Illustration of the differences in the low-pressure circuit in the D20 engine as an example .............32
3.4.1.1 High-pressure pump, lubricated with engine oil, and with external hot/cold circuit (EuroIII) ............32
3.4.1.2 High-pressure pump, lubricated with fuel, and internal hot/cold circuit (EuroIV, EuroV, EEV).........33
3.5 Fuel Service Center (KSC)................................................................................................................34
3.5.1 Fuel filter replacement.......................................................................................................................36
3.6 Pressure-limiting valve (DBV) ...........................................................................................................37
3.7 Proportional valve (ZME) ..................................................................................................................38
3.8 Display messages and check lamps.................................................................................................39
3.9 Calling up system faults in the instruments.......................................................................................40
3.10 Identification of hardware and software control units:.......................................................................42
3.11 D2676LF22 engine with emission class EuroV and EGR.................................................................45
3.11.1 Engine view 1 – front and left............................................................................................................45
3.11.2 Engine view 2 – front.........................................................................................................................46
3.11.3 Engine view 3 – rear .........................................................................................................................47
3.11.4 Engine view 4 – right-hand side........................................................................................................48
3.12 Overview of the sensors for monitoring and controlling the exhaust gas aftertreatment..................49
4 Software versions: ..........................................................................................................................50

5 Function parameters (FUP) ............................................................................................................51

5.1 EDC 7 engine control unit .................................................................................................................51
6 Repair notes/diagnosis: .................................................................................................................54

3438PEen
Page 3 of 157
6.1 Troubleshooting/elimination of faults after problems or symptoms:..................................................54
6.2 Extensions/process descriptions in MAN-cats II ...............................................................................65
6.2.1 Monitoring..........................................................................................................................................65
6.2.1.1 Overview of the input variables that work with replacement values
in the event of a defect categorisation ............................................................................................. 65
6.2.1.2 Monitoring Temperatures ................................................................................................................. 66
6.2.1.3 Monitoring pressures........................................................................................................................ 68
6.2.1.4 Monitoring Rail control (proportional valve) In MAN-cats, the term
"Rail control (proportional valve)" is also referred to as Rail control (proportioning unit)................. 70
6.2.1.5 Monitoring Engine speeds................................................................................................................ 72
6.2.1.6 Monitoring Engine values ................................................................................................................. 74
6.2.1.7 Monitoring Cylinders......................................................................................................................... 77
6.2.1.8 Monitoring Status of the injectors ..................................................................................................... 81
6.2.1.9 Monitoring Status information........................................................................................................... 82
6.2.1.10 Monitoring specifications/messages from FFR ................................................................................ 86
6.2.1.11 Monitoring Charging pressure governing system (EuroIV, EEV)..................................................... 89
6.2.1.12 Monitoring Exhaust gas aftertreatment ............................................................................................ 91
6.2.1.13 Monitoring of exhaust gas recirculation............................................................................................ 96
6.2.1.14 Monitoring Lambda values ............................................................................................................. 102
6.2.2 Engine test function........................................................................................................................ 105
6.2.2.1 Actuator test ................................................................................................................................... 106
6.2.2.2 Compression test ........................................................................................................................... 107
6.2.2.3 Rev-up test ..................................................................................................................................... 109
6.2.2.4 Cylinder cutoff test.......................................................................................................................... 113
6.2.2.5 High-pressure test .......................................................................................................................... 114
6.2.2.6 Checking the pressure-limiting valve (test) with MAN-cats II......................................................... 117
6.2.3 Measuring the leakage quantity, pressure-limiting valve open test using
DLS tester and MAN-cats II............................................................................................................ 119
6.2.3.1 Measuring principle to test for leaks............................................................................................... 120
6.2.3.2 Test setup....................................................................................................................................... 121
6.2.3.3 Connection of the DLS tester ......................................................................................................... 122
6.2.3.4 Measuring the leakage quantity using the DLS tester ................................................................... 124
6.2.3.5 Testing the pressure-limiting valve (pressure-limiting valve open test) using the DLS tester ....... 129
6.2.4 Workshop routines within EDC diagnosis ...................................................................................... 132
6.2.4.1 Withdrawing torque limiting ............................................................................................................ 132
6.2.4.2 Initialisation of the lambda correction value ................................................................................... 134
6.2.5 Evaluations ..................................................................................................................................... 136
6.2.5.1 Operating data................................................................................................................................ 137
6.2.5.2 Signal analysis................................................................................................................................ 138
6.2.5.3 Reset all values after replacing particulate filter In MAN-cats, the term
"Reset all values after replacing particulate filter" is also referred to as
Reset all values after exchanging particulate trap ......................................................................... 142
6.2.5.4 EDC trend data............................................................................................................................... 143
7 Literature/tools, etc. ..................................................................................................................... 144
7.1 Repair manuals: ............................................................................................................................. 144
7.2 System description ......................................................................................................................... 144
7.3 MAN-cats II software: ..................................................................................................................... 144
7.4 Service Information sheets............................................................................................................. 144
7.5 Tools............................................................................................................................................... 146
7.5.1 Tools - electrical system................................................................................................................. 146
7.5.2 Tools - Common Rail injection system, AdBlue system................................................................. 149
8 Error message/descriptions:....................................................................................................... 151

9 Circuit diagrams:.......................................................................................................................... 152

9.1 EDC 7 C3 and EDC 7 C32 (version: 07/2010)............................................................................... 152
9.2 Overview, EDC 7 fuel diagrams (version: 07/2010) ....................................................................... 156
9.2.1 D2868LF02/LF03 (V8) engine fuel diagram — up to approx. October 2007 ................................. 156
9.2.2 D2868LF02/LF03 (V8) engine fuel diagram — as from approx. October 2007 ............................. 157

3438PEen
Page 4 of 157
Modification index

Index: Date: Description: Section:

-- 01.09.2010 First edition ---

3438PEen
Page 5 of 157
1 Review
The Common Rail injection system with the EDC 7 control unit was introduced in the D0836 engine at
MAN in 2002; the engine of the D20 series then followed in 2004, and all the other series followed suit in
the subsequent years. To date, the EDC 7 control unit and the Common Rail injection system have been
continuously enhanced and optimised. The most important information about this can be found below.

2 Short descriptions

2.1 Common Rail injection system:

A good mixture formation is the prerequisite for efficient combustion and consequently favourable fuel
consumption, lower emissions in the exhaust gases and a smooth-running engine. The Common Rail
injection system plays a central role in this. The correct volume of fuel must be injected at the right time
and with a high pressure.
One system that satisfies these requirements is the accumulator or Common Rail injection system.
The essential features of the Common Rail injection system are as follows:
• The injection pressure is generated independently from the engine speed and the engine load.
• Separation of the injection pressure and injection time functions. This creates numerous
optimisation possibilities with regard to fuel consumption and exhaust emissions.
• High injection pressures even at low engine speeds. Apart from other benefits, this permits
low-smoke driveaway characteristics.
• Low injection pressures in the partial load range lead to excellent nitrogen oxide (NOx) values.
• In combination with the EDC 7 control unit, multiple injections are possible (especially when idling
and in partial-load operation).
• Pre-injection ensures low noise values through low pressure peaks.
• Improved cold-starting behaviour through pre-injection.
• The injection pressure remains constant even at higher fuel temperatures.
• Low peak drive torque at the high-pressure pump reduces noise generation and loading
in the timing gear.

The generation of the injection pressure and the injection are decoupled in the Common Rail injection
system. The fuel for the individual cylinders comes from a shared accumulator (rail) which is constantly kept
at high pressure. The accumulator is pressurised by a high-pressure pump. This pressure can be changed to
suit the operating conditions in question.
Each cylinder in the engine is equipped with an injector which is controlled by a solenoid valve. The injection
volume is determined by the outlet cross-section of the injector, the solenoid valve opening duration and the
accumulator pressure. At MAN, hydraulic components are/have been fitted in which a system pressure of up
to 1800 bar can be achieved (status 07/2010). In future, rail pressures of up to 2500 bar and higher are
anticipated.
Separation of the injection pressurisation and injection functions allows a better injection characteristic and,
therefore, improves combustion development. The injection pressure may be selected freely from the maps
stored in the EDC 7 control unit. Multiple injections per working cycle, i.e. pre-injections, main injection and
possibly post-injections, are possible. The fuel volume, start of the injection and the injection are controlled
by extremely fast solenoid valves in the injectors.

3438PEen
Page 6 of 157
At MAN Nutzfahrzeuge, there are currently three variants of the Common Rail injection system with different
injection pressures in use:
Date: 07/2010
Variant 1:
EDC 7 C3 control unit, design of the Common Rail injection system for 1600 bar fuel system pressure.
At MAN, however, the first engines – such as the D0836LFL40, the D2876LF12 or the D28 V-engine – are
only operated with a Rail pressure of 1400 bar.

Variant 2:
EDC 7 C32 control unit, 1600 bar fuel system pressure. In use in EuroIV, e.g. in the D2066LF31 engine

Variant 3:
EDC 7 C32 control unit, 1800 bar fuel system pressure. In use e.g. in the engine D08 EuroV and D20
(e.g. D2066LF51) and D26 with EGR.

3438PEen
Page 7 of 157
Main components of the Common Rail injection system
High-pressure pump
The volume-controlled high-pressure pump delivers as much fuel as required to the rail until the desired
fuel pressure (Rail pressure) is reached.
Rail
The Rail contains a defined accumulator volume at the fuel pressure required for the injection. The Rail
is connected individually to all the solenoid-valve-controlled injectors via high-pressure fuel lines.
A Rail pressure sensor is attached to the Rail to measure the fuel pressure.
Injector
Every injector in the Common Rail injection system is controlled by a quick-action solenoid valve.
By actuating the solenoid valve, the injectors can inject a defined volume of fuel from the Rail into the
combustion chambers of the engine. Multiple electrical actuation of the solenoid valve enables multiple
injections (up to 5 per working cycle).

Schematic representation of the Common Rail injection system:

1 Volume-controlled high-pressure pump with 5 Injectors

gear pump and proportional valve. 6 EDC 7 control unit
2 Rail 7 Sensors and actuators
3 Pressure-limiting valve
4 Rail pressure sensor

3438PEen
Page 8 of 157
2.2 EDC 7 control unit for the Common Rail injection system

2.3 Basic functions of the control unit:

The essential task of the EDC 7 control unit is to control the fuel injection at the right time and in the right
volume, adapted to the varying operating and general conditions.
For example, the EDC 7 control unit, the volume-controlled high-pressure pump and the Rail pressure
sensor combine to form a control circuit. Other sensors such as the coolant temperature sensor, charge-air
temperature sensor or atmospheric pressure sensor help to adjust and optimise the engine for changing
conditions.
The injection timing and the fuel volume are calculated individually for every cylinder and injected into the
injectors via quick-action solenoid valves.
The injection for each working cycle is divided into three groups:
• Pre-injection
• Main injection
• Post-injection
In contrast to the pre-injection and the main injection, the fuel is not burned during the post-injection, but
rather is evaporated with residual heat in the cylinder. This enriched exhaust gas-fuel mixture is fed via the
exhaust valves to the exhaust system during the exhaust stroke. In appropriate NOx catalytic converters,
the fuel in the exhaust gas acts as a reducing agent for the nitrogen oxide and so reduces the NOx values.
An additional task of the control unit is the starting control. The data exchange between the immobilizer
integrated in the vehicle management computer (FFR) and the EDC control unit indicates whether the safety
criteria for the actuation of the starter are being fulfilled and a defined fuel volume for the starting procedure
has been released.
For further information, see the EDC 7 system description. See Section 7.2.

The most important basic functions of the EDC 7 are shown below:

• Volume setpoint definition, volume limitation

• Height-dependent injection correction
(turbo charger protection) through an atmospheric pressure sensor integrated in the control unit.
If the atmospheric pressure is low at a high altitude, a critical turbocharger speed may be reached
due to the lower air throughput. The injection volume is therefore limited and the possibility of
overspeed is prevented in order to protect the turbocharger.
• Starting control
The actuation of the IMR (Integriertes mechanisches Relais, integrated mechanical relay) for the
starter is enabled by the EDC 7 control unit. The relevant command is sent via the CAN data bus
engine from the vehicle management computer (FFR)
• Fuel metering
• Fuel pressure control
• Fuel pressure switch-off
Switchover to an emergency operation function which makes it possible to drive the vehicle out of a
hazardous situation and/or to the nearest workshop using a defined Rail pressure of approx. 800 bar
and reduced power.
• Idling control
• Maximum-speed governor, smoke limitation and torque limiting
• Adaptive cylinder balancing control (smooth running control – active during idling only)
• Cylinder shut-off
• Exhaust gas recirculation
• Charge air, exhaust gas aftertreatment the term exhaust gas aftertreatment is also referred to
as exhaust post-treatment in MAN-cats

3438PEen
Page 9 of 157
 • Exhaust gas temperature and exhaust gas management
• Charging pressure governing system
• Signal acquisition and calculation of operating variables
• Diagnosis and monitoring function
• On-Board Diagnosis (OBD) functionality, from Euro IV
• EDC internal temperature
The lowest and highest temperatures in the control unit are permanently stored.

2.3.1 Setpoint formation for fuel volumes

One of the elementary functions in the EDC is the setpoint formation for fuel volumes for the respective
engine operating modes. Setpoint formation for fuel volumes includes the following sub-functions:
• Starting volume
The injection volume for the engine start is calculated optimally and adapted to the prevalent
general conditions, in order to guarantee a quick engine start with a minimum formation of smoke.
The starting volume calculation is divided into three phases: Starting volume enabling, injection
volume during start and engine start (reaching the minimum speed for engine running by itself).
• Idling control
The task of the idling control consists of maintaining a constant engine speed during idling
regardless of the operating conditions, e.g. a cold or warm engine, a loaded alternator,
activated air-conditioning system, etc.
• Intermediate speed control
The intermediate speed control maintains the engine speed(s) constant even with varying engine
loads, e.g. when using a power take-off and the operation of additional devices such as hydraulic
units, a crane, etc.
• Torque limiting (from version EDC 7 C32 V31 – OBD 1b with NOx check measurement)
The torque limiting function processes requests for limitation of the injection volumes in the event
of NOx-related faults in the vehicle. This is stipulated in the context of the OBD legislation.
The request for torque limiting due to NOx-related faults may come both from the system EDC itself
and also from the AdBlue system in vehicles with SCR exhaust gas aftertreatment.
• Fuel-volume limitation
Various factors may make it necessary to limit the fuel volume. This is intended to prevent the
following undesirable effects:
- Excessive emissions
- Excessive soot emissions
- Mechanical overload due to excessive torque or engine overspeeding
- Thermal overload due to excessive exhaust gas, coolant, oil or turbocharger temperature
• Maximum-speed governor
In MAN-cats, the term "maximum-speed governor" is referred to as "top-speed governing" and "limit
speed control"..
• The task of the maximum-speed governor is to protect the engine against impermissibly high
speeds. The maximum permissible speed for every engine type is stipulated, which must never
be exceed for a relatively long period of time. Otherwise, there is a danger of engine damage.
• Fuel-volume setpoint
The required fuel-volume setpoint is calculated from various input variables (driver request,
coolant temperature, charging pressure, etc.) and the various fuel-volume limitations.

3438PEen
Page 10 of 157
2.3.2 Injection start control
The injection start has considerable influence over the power, fuel consumption, noise emissions and
exhaust gas behaviour. The setpoint for the injection start is determined by the engine speed and the
required injection volume. The values for the injection start are stored in maps.
This module covers the calculation of the injection start for the following:
• Pre-injection
• Main injection
• Post-injection

Apart from the engine speed and injection volume, the following factors among others also influence the
calculation of the injection start:
• Coolant temperature
• Charge-air temperature
• Atmospheric pressure
• EGR rate
• Engine start phase

2.3.3 Fuel metering

In this module, the fuel metering is calculated for the individual operating modes such as engine start, idling,
driving or coasting, etc., based on the duration of the injection, i.e. the activation of the injectors in relation to
the fuel pressure.

2.3.4 Fuel pressure control

The fuel pressure control module is responsible for the setpoint formation of the fuel pressure, the fuel
pressure regulator and the fuel pressure monitoring.
The function setpoint formation of fuel pressure determines the fuel pressure setpoint depending on
the following variables:
• Engine speed
• Desired volume for formation of volume setpoint
• Coolant temperature
• Charge-air temperature
• Charging pressure
• Position of the EGR shut-off flap
• Injection volume specification from the vehicle management computer (FFR)
• Status of the particulate filter regeneration
• Request for reduction of NOx in the engine
• Engine brake
The function fuel pressure control sets the Rail pressure using a proportional valve (ZME).
The fuel pressure monitoring is responsible for monitoring the system for possible deviations such as
excessive or insufficient Rail pressure, impermissible pressure control differences or deviations in the
Rail pressure controller or leaks.

2.3.5 Adaptive individual cylinder torque control (smooth running control)

The main task of the adaptive individual cylinder torque control (smooth running control) is to find the ‘right’
rotation acceleration for the engine. This is intended to ensure the engine to run smoothly, especially when
idling.
3438PEen
Page 11 of 157
The adaptive adaptive individual cylinder torque control (smooth running control) is therefore only
active when idling!
The monitoring of the engine speed identifies the cylinders that have a higher/lower torque output than the
average torque per cylinder. The cause for a deviating torque output may be differing cylinder compression,
differing frictional forces or volume fluctuations in the injectors.
A corresponding algorithm then individually adjusts the fuel volume for each cylinder.
Further information can be found in the system description T 18, Rail injection, among other sources.
Common Rail injection system EDC 7. See Section 7.2.

2.3.6 Air system, exhaust gas aftertreatment

2.3.6.1 Charging pressure governing system

The charging pressure governing system improves the torque characteristics in the full load range and load
changes in the partial load range.
The setpoint for the charging pressure and/or for the calculation of a duty cycle for actuating an actuator
(wastegate capsule) is determined on the basis of the following input variables:
• Engine speed
• Charge-air temperature
• Atmospheric pressure
• Charging pressure
• Position of the EGR shut-off flap
• Volume setpoint
• Engine brake request

3438PEen
Page 12 of 157
2.3.6.2 Exhaust gas recirculation (EGR)
Reduction of the nitrogen oxides (NOx) in exhaust gas is an essential precondition for achieving compliance
with currently valid emission regulations.
The exhaust gas recirculation is a measure for reducing the NOx shares in the exhaust gas.
With exhaust gas recirculation, part of the exhaust gas is added to the inducted air volume to further reduce
the combustion temperature. This measure increases the specific heat capacity of the intake air and reduces
the oxygen content.
Over the years, the control/governing of the external exhaust gas recirculation has been enhanced so that
there are now three versions in use at MAN:
• Non-controlled exhaust gas recirculation (from EDC 7 C3 V24)
The EGR adjusting cylinder is actuated by the EDC 7 control unit. The EGR is deactivated under
certain temperature conditions, firstly to prevent the condensation of sulphurous acids at low charge
air temperatures and secondly to prevent excessive heating of the charge air by the recirculated
exhaust gas. The EGR adjusting cylinder has a built-in dry-reed contact which monitors the EGR
shut-off flap position, to detect whether the EGR shut-off flap is open or closed.
The non-controlled exhaust gas recirculation is used in the D08, D20, D26 and D28 engine series
with EuroII, EuroIII and EuroIV (classification pending).

• Position-controlled exhaust gas recirculation (from EDC 7 C32 V25)

Engines with the EuroIV emission class have been/are fitted with an externally cooled and infinitely
controllable exhaust gas recirculation.
The EGR shut-off valve used for control is located in the EGR module at the input of the exhaust
gas cooler and is operated by a pneumatic EGR adjusting cylinder. A flap angle corresponding to
a specific EGR rate is stored in the engine map for each operating condition. The EGR adjusting
cylinder travels to the predefined flap angle. EGR rates between 0 % and 30 % can be implemented.
For example, in an engine with EuroV, the maximum recirculation rate is 30 %.
The position-controlled exhaust gas recirculation is used in the D08, D20 and D26 engine series with
EuroIV and OBD1.

• Position- and lambda-controlled exhaust gas recirculation (from EDC 7 C32 V43)
In order to reliably comply with the more stringent NOx limit values applicable from EuroV, an even
more precise EGR governing system is required. This is achieved by storing an EGR rate instead
of a flap angle in the engine map for each operating condition.
The oxygen concentration in the exhaust gas flow is measured using a oxygen sensor built into
the exhaust pipe and the actual EGR rate is calculated from this. The term “lambda probe” is also
referred to as “oxygen sensor” in MAN-cats. This value is compared with the specified values of the
EDC 7 control unit and, in the event of discrepancies, it is regulated in a control circuit with the EGR
adjusting cylinder.
The lambda-controlled exhaust gas recirculation is used in the D08, D20 and D26 engine series with
EuroV or EEV and OBD2.

3438PEen
Page 13 of 157
Due to the variety of series and types for engines with the Common Rail injection system and the different
versions of exhaust gas recirculation systems, you will find below reference values that are crucial for the
enabling and/or disabling of the exhaust gas recirculation.
The exhaust gas recirculation is blocked and/or the EGR shut-off valve is closed:
• at a coolant temperature below approx. 60 °C or over approx. 95 °C
• at a charge-air temperature after the intercooler below approx. 10 °C or over approx. 70 °C
• at an engine speed below approx. 1100 rpm
• in the partial load range
• during acceleration or in engine braking mode

Further information can be found in the system description T 18, Rail injection, among other sources.
Common Rail injection system EDC 7. See Section 7.2.

3438PEen
Page 14 of 157
2.3.6.3 Engine protection functions
To protect the engine against mechanical and/or thermal overloads, the engine torque, i.e. the fuel injection
volume, is reduced when certain operating circumstances occur, when specified sensor actual values are
exceeded or when certain functions are deactivated.
Below, you will find a list of the factors which may limit the engine torque in the context of engine protection
functions.
Note:
Engine protection functions may lead to a considerable reduction in power. This may lead to a modified
driving style which could in turn lead to increased fuel consumption. These factors should therefore be taken
into account when searching for causes in the event of complaints about power output and fuel consumption.

Reasons for a possible reduction in the fuel injection volume (across all engine series and emission
classes):
• Ambient air temperature is in the range between approx. + 30 and + 55 °C
• Ambient air temperature is in the range between approx. + 30 and + 45 °C
in vehicles additionally equipped with cooling equipment (radiator and intercooler) for countries with
ambient air temperature above approx. 35 °C. The term “ambient air temperature” is also referred to
as air temperature and external temperature in MAN-cats.
• Coolant temperature higher than approx. 98 °C
• Exhaust gas recirculation has been blocked (in engines with exhaust gas recirculation) and coolant
temperature is higher than approx. 98 °C and/or mixture temperature (intake air and exhaust) in the
air distributor pipe (intake manifold) is higher than approx. 80 °C
• As protection for the SCR catalytic converter or the PM catalytic converter or with a diesel oxidation
catalytic converter at exhaust gas temperatures higher than 560 °C.

3438PEen
Page 15 of 157
2.4 Additional functions
Apart from the basic function of the EDC 7 control unit, which essentially ensures normal operation, there
are various additional functions integrated in the control unit which can assist the workshop when repairing
the engine.
• Engine test functions
- Actuator test
- Compression test
- Rev-up test
- Cylinder shut-off test
- High-pressure test
- Pressure-limiting valve open test (In MAN-cats, also referred to as opening test for
pressure-limiting valve.)

Detailed information can be found in Section 6.2.2.

2.5 Schematic diagrams of the signal processing in the EDC 7 systems

The diagrams on the following pages are designed to give you a schematic insight into which sensors and/or
interfaces the internal signal processing consists of and, for example, how it supports the calculation of the
necessary injection volumes or the calculation of the injection start. The output variables (actuators, etc.)
are activated depending on the completed calculations.

3438PEen
Page 16 of 157
2.5.1 Schematic diagram of signal processing in D08 Common Rail EuroIV engine with
PM catalytic converter

Input variables (sensors, etc.)

Charge air temperature
Crankshaft speed from FFR via CAN
after EGR
Camshaft speed Injection volume specification
Feedback on the position
(Accelerator pedal)
Rail pressure of the EGR shut-off flap
Intermediate speed – setpoint
Charging pressure Atmospheric pressure Ambient air temperature
Idling speed increase
Charge air temperature Torque reduction
Oil pressure
before EGR Maximum governed speed
Exhaust relative pressure
Fuel pressure (low pressure)
before PM catalytic converter
Coolant temperature

Signal processing in the control unit

Calculation of the Calculation of the Rail Calculation for activating the
pre-injection, main injection pressure on the basis of pulse valve of the exhaust
and post-injection and/or the following factors: turbocharger for charging
injection duration on the basis • Engine speed pressure governing system
of the following factors: • Injection volume specification on the basis of the following
• Engine speed • Coolant temperature factors:
• Rail pressure • Charge-air temperature • Engine speed
• Injection volume specification • Charge air pressure • Injection volume specification
• Coolant temperature • Activation duty cycle of • Charging pressure
• Charge-air temperature the EGR shut-off flap • Charge-air temperature
• Charging pressure • Change speed of the • Atmospheric pressure
• Atmospheric pressure injection volume specification Status monitoring of the PM
• Position of the EGR shut-off Calculation of the activation catalytic converter (blockage,
flap and control of the EGR shut-off breaks) on the basis of the
• Fault monitoring flap on the basis of the following factors:
Calculation of the injection following factors: • Engine speed
start of the pre-injection, main • Engine speed • Injection volume
injection and post-injection • Injection volume specification specification/charging
on the basis of the following • Charging pressure pressure
factors: • Coolant temperature • Exhaust relative pressure
• Engine speed • Charge-air temperature before PM catalytic converter
• Injection volume specification • Atmospheric pressure • Exhaust gas temperature
• Coolant temperature • Feedback on the position before PM catalytic converter
• Atmospheric pressure of the EGR shut-off flap
• Charge-air temperature • Change speed of the engine
• Activation duty cycle of the speed
EGR shut-off flap • Change speed of the
• Change speed of the engine injection volume specification
speed
• Change speed of the
injection volume specification

Output variables (actuators)

Injectors Proportional valve (ZME) EGR adjusting cylinder
Pulse valve of the
Starter control
exhaust turbocharger

3438PEen
Page 17 of 157
2.5.2 Schematic diagram of signal processing in D20 Common Rail EuroIV engine with PM
catalytic converter

Input variables (sensors, etc.)

Charge air temperature
Crankshaft speed from FFR via CAN
after EGR
Camshaft speed Injection volume specification
Feedback on the position
(Accelerator pedal)
Rail pressure of the EGR shut-off flap
Intermediate speed – setpoint
Charging pressure Atmospheric pressure Ambient air temperature
Idling speed increase
Charge air temperature Torque reduction
Oil pressure
before EGR Maximum governed speed
Exhaust relative pressure
Fuel pressure (low pressure)
before PM catalytic converter
Exhaust gas temperature
Coolant temperature
before PM catalytic converter

Signal processing in the control unit

Calculation of the Calculation of the injection Status monitoring of the PM
pre-injection, main injection pressure on the basis of the catalytic converter (blockage,
and post-injection and/or following factors: breaks) on the basis of the
injection duration on the basis • Engine speed following factors:
of the following factors: • Injection volume specification • Engine speed
• Engine speed • Coolant temperature • Injection volume
• Rail pressure • Charge-air temperature specification/charging
• Injection volume specification • Charge air pressure pressure
• Coolant temperature • Activation duty cycle of • Exhaust relative pressure
• Charge-air temperature the EGR shut-off flap before PM catalytic converter
• Charging pressure • Change speed of the • Exhaust gas temperature
• Atmospheric pressure injection volume specification before PM catalytic converter
• Position of the EGR shut-off Calculation of the activation
flap and control of the EGR shut-off
• Fault monitoring flap on the basis of the
• Exhaust gas temperature following factors:
before PM catalytic converter • Engine speed
Calculation of the injection • Injection volume specification
start of the pre-injection, main • Charging pressure
injection and post-injection • Coolant temperature
on the basis of the following • Charge-air temperature
factors: • Atmospheric pressure
• Engine speed • Feedback on the position
• Injection volume specification of the EGR shut-off flap
• Coolant temperature • Change speed of the
• Atmospheric pressure engine speed
• Charge-air temperature • Change speed of the
• Activation duty cycle of the injection volume specification
EGR shut-off flap
• Change speed of the engine
speed
• Change speed of the
injection volume specification

Output variables (actuators)

Injectors Proportional valve (ZME) EGR adjusting cylinder
Starter control

3438PEen
Page 18 of 157
2.5.3 Schematic diagram of signal processing in D08 Common Rail EuroIV/EEV engine with
NOx check measurement and CRT particulate filter

Input variables (sensors, etc.)

Charge air temperature
Crankshaft speed from FFR via CAN data bus
after EGR
Camshaft speed Injection volume specification
Feedback on the position
(Accelerator pedal)
Rail pressure of the EGR shut-off flap
Intermediate speed – setpoint
Charging pressure Atmospheric pressure Ambient air temperature
Idling speed increase
Charge air temperature Torque reduction
Oil pressure
before EGR Maximum governed speed
Exhaust gas differential
Fuel pressure (low pressure)
pressure at CRT particulate filter
Exhaust gas temperature before
Coolant temperature Oxygen sensor
the CRT particulate filter

Signal processing in the control unit

Calculation of the pre-injection, Calculation of the injection Calculation for activating the
main injection and post-injection pressure on the basis of the pulse valve of the exhaust
and/or injection duration on the following factors: turbocharger for charging
basis of the following factors: • Engine speed pressure governing system
• Engine speed • Injection volume specification on the basis of the following
• Rail pressure factors:
• Coolant temperature
• Injection volume specification • Charge-air temperature • Engine speed
• Coolant temperature • Charge air pressure • Injection volume specification
• Charge-air temperature • Activation duty cycle of the • Charging pressure
• Charging pressure EGR shut-off flap • Charge-air temperature
• Exhaust gas temperature • Change speed of the injection • Atmospheric pressure
• Atmospheric pressure volume specification Status monitoring of the PM
• Position of the EGR shut-off flap Calculation of the activation CRT particulate filter (blockage,
• Fault monitoring and control of the EGR shut-off breaks, load) on the basis of the
• Exhaust gas temperature before flap on the basis of the following factors:
the CRT particulate filter following factors: • Engine speed
Calculation of the injection start • Engine speed • Injection volume specification
of the pre-injection, main • Injection volume specification • Charging pressure
injection and post-injection on • Charging pressure • Exhaust gas differential pressure
the basis of the following factors: • Coolant temperature at CRT particulate filter
• Engine speed • Charge-air temperature • Exhaust gas temperature before
• Injection volume specification • Atmospheric pressure the CRT particulate filter
• Coolant temperature • Feedback on the position of Monitoring of the NOx emissions
• Atmospheric pressure the EGR shut-off flap in the exhaust gas on the basis
• Charge-air temperature • Change speed of the engine of the following factors:
• Activation duty cycle of the speed • Lambda value
EGR shut-off flap • Change speed of the injection • Exhaust gas temperature
• Change speed of the engine volume specification • Exhaust gas differential pressure
speed at CRT particulate filter
• Change speed of the injection • Charge-air temperature
volume specification • Coolant temperature

Output variables (actuators, etc.)

Injectors Proportional valve (ZME) EGR adjusting cylinder
OBD fault light Pulse valve of the exhaust
Starter control
turbocharger
Engine air flow sensor flap CRT particulate filter forced
solenoid valve regeneration

3438PEen
Page 19 of 157
2.5.4 Schematic diagram of EDC signal processing in D20, D26 Common Rail EuroV engines
with NOx check measurement, MAN AdBlue and SCR catalytic converter

Input variables (sensors, etc.)

Crankshaft speed Atmospheric pressure NOx concentration
Camshaft speed Oil pressure from AdBlue system via CAN
data bus
Exhaust gas temperature before
Rail pressure Fill level of the AdBlue tank
the SCR catalytic converter
Exhaust gas temperature after
Charging pressure from FFR via CAN data bus the SCR catalytic converter
Charge-air temperature Injection volume specification Status information for reduction
(accelerator pedal) of NOx in the engine
Fuel pressure (low pressure) Intermediate speed – setpoint Status information for torque
Idling speed increase reduction
Coolant temperature Torque reduction Ambient air temperature
Maximum governed speed Humidity

Signal processing in the control unit

Calculation of the pre-injection, Calculation of the injection Monitoring of existence of
main injection and post-injection pressure on the basis of the diverse components in the
and/or injection duration on the following factors: AdBlue system on the basis
basis of the following factors: • Engine speed of the following factors:
• Engine speed • Injection volume specification • Engine speed
• Rail pressure • Coolant temperature • Injection volume
• Injection volume specification • Charge-air temperature specification/charging pressure
• Coolant temperature • Charge air pressure • Exhaust gas temperature
• Charge-air temperature • Change speed of the injection before the SCR catalytic
• Charging pressure volume specification converter
• Atmospheric pressure Calculation of the untreated NOx • Exhaust gas temperature after
• Fault monitoring emissions and/or the desired the SCR catalytic converter
emissions on the basis of the • NOx emissions from the NOx
Calculation of the injection start
following factors: sensor
of the pre-injection, main
injection and post-injection • Exhaust mass flow
• Engine speed
on the basis of the following • Injection volume specification Switching to NOx reduction in
factors: the engine:
• Exhaust mass flow
• Engine speed • Rail pressure • Rail pressure correction
• Injection volume specification • Coolant temperature • Change to injection start
• Coolant temperature • Charge-air temperature Switching to reduced-power
• Atmospheric pressure • Lambda correction value full load:
• Charge-air temperature • Humidity and temperature limitation of the full-load map
• Change speed of the engine in the air filter
speed • Injections start
• Change speed of the injection
volume specification

Output variables (actuators)

Injectors from the EDC via CAN data bus to the AdBlue system
Proportional valve (ZME) Untreated NOx emissions Torque
Desired NOx emissions after the Atmospheric pressure
Starter control SCR catalytic converter Charging pressure
Exhaust gas temperature before Charge-air temperature
the SCR catalytic converter Metering enabling
Exhaust mass flow Heating enabling
Injection volume Date and time
Coolant temperature Mileage (km)

3438PEen
Page 20 of 157
2.5.5 Schematic diagram of MAN AdBlue signal processing in D20 Common Rail EuroV engine
with NOx check measurement, MAN AdBlue and SCR catalytic converter

Input variables (sensors, etc.)

Exhaust gas temperature after Ambient air temperature Humidity

the SCR catalytic converter AdBlue pressure NOx concentration
Air pressure after throttle from the EDC via CAN data bus to the AdBlue system
Air pressure ahead of throttle Untreated NOx emissions Torque
Desired NOx emissions after the Atmospheric pressure
Fill level in the AdBlue tank
SCR catalytic converter Charging pressure
AdBlue temperature in the Exhaust gas temperature before Charge-air temperature
AdBlue tank the SCR catalytic converter Metering enabling
Exhaust mass flow Heating enabling
AdBlue temperature in pump Injection volume Date and time
module
Coolant temperature Mileage (km)

Signal processing in the control unit

Calculation of the metering • Ambient air temperature • Speed of the AdBlue pump
strategy on the basis of the • AdBlue pressure • Exhaust gas temperature
following factors: • Request for heating enabling before the SCR catalytic
Parameters for after-running converter
• Untreated NOx emissions
and freezing strategy: • Exhaust gas temperature
• Desired NOx emissions
after the SCR catalytic
• Exhaust gas temperature • Engine speed converter
before the SCR catalytic • AdBlue pressure • Fill level in the AdBlue tank
converter • AdBlue temperature in the • AdBlue consumption
• Exhaust gas temperature tank
after the SCR catalytic • Atmospheric pressure
• AdBlue temperature,
converter metering valve NOx check system:
• Exhaust mass flow • Ambient air temperature • Untreated NOx emissions
• Injection volume • Air pressure ahead of throttle • Desired NOx emissions
• Exhaust gas back pressure Factors for on-board • Back-calculated desired
correction diagnosis: emissions
• AdBlue pressure correction • Limit degree of efficiency
• Engine speed
Calculation of the heating 3.5 g/kWh
• AdBlue pressure
strategy for AdBlue on the • Limit degree of efficiency
• AdBlue temperature in the 7.0 g/kWh
basis of the following factors:
tank
• Battery voltage • AdBlue temperature in the Request for reduction in the
• Engine speed metering valve engine
• AdBlue temperature in the • Air pressure ahead of throttle Request for torque reduction
tank • Air pressure ahead of throttle
• AdBlue temperature in pump
module
• AdBlue temperature in the
metering valve

Output variables (actuators)

Metering module from the AdBlue system via CAN data bus to the EDC system
AdBlue pump in supply module Fill level of the AdBlue tank NOx reduction in the engine
Exhaust gas temperature after Status information for torque
Air-control valve in the supply the SCR catalytic converter reduction
module Status information for Ambient air temperature
Bleed valve in the supply module Humidity

Coolant valve, AdBlue heater

circuit

3438PEen
Page 21 of 157
2.6 Data exchange with other control units (CAN data-bus architecture)
Upon the introduction of OBD, a change in the CAN data-bus architecture became necessary for technical
reasons. The background involved, among other factors, the diagnostic access using MAN-cats II.
CAN data-bus architecture:
inline engine up to EDC 7 C32 control unit V25 (without OBD)

1 1 Without CAN terminating resistor

A 8
2 CAN terminating resistor (120 Ω)
7 2 3 AdBlue control unit in the supply
module
4 AdBlue fill level sensor and
AdBlue temperature sensor
10 5 NOx sensor
9 6 EDC control unit
7 Vehicle management computer
8 Diagnostics socket X200
9 CAN data bus engine (orange)
3
10 CAN data bus OBD/EGR (green)

A Cab
6 4 B Engine
C Frame

B C
5

Inline engine from EDC 7 C32 control unit V27 (with OBD)

1 Without CAN terminating resistor

A 9 1
8 2 CAN terminating resistor (120 Ω)
2 3 CAN terminating resistor,
switchable; please observe the
note at the end of the section!
3
4 AdBlue control unit in the supply
module
11
10 5 AdBlue fill level sensor and
AdBlue temperature sensor
6 NOx sensor
7 EDC control unit
4 8 Vehicle management computer
12
9 Diagnostics socket X200
10 CAN data bus engine (orange)
7 5 11 CAN data bus OBD (green)
12 CAN data bus EGR (blue)

A Cab
B C B Engine
6 C Frame

3438PEen
Page 22 of 157
there are e up to EDC 7 C32 control units V25 (without OBD)

1 1 Without CAN terminating resistor

A 8 2 CAN terminating resistor (120 Ω)
7
2 3 AdBlue control unit in the
supply module
4 AdBlue fill level sensor and
AdBlue temperature sensor
5 NOx sensor
10
6 EDC control units, Master, Slave
9
7 Vehicle management computer
8 Diagnostics socket X200
9 CAN data bus engine (red)
10 CAN data bus EGR (green)
3 11 CAN data bus control units,
Master – Slave (blue)

6 11
4 A Cab
B Engine
C Frame

B C
5

V-type engine from EDC 7 C32 control units V27 (with OBD) 1 Without CAN terminating resistor
2 CAN terminating resistor (120 Ω)
3 CAN terminating resistor,
A 1
9 switchable; please observe the
8 note at the end of the section!
2 4 AdBlue control unit in the supply
module
3 5 AdBlue fill level sensor and
AdBlue temperature sensor
10 11 6 NOx sensor
7 EDC control units, Master, Slave
8 Vehicle management computer
9 Diagnostics socket X200
12
10 CAN data bus engine (red)
4
11 CAN data bus OBD (green)
12 CAN data bus EGR (dark blue)
7 5 13 CAN data bus control units,
13 Master – Slave (light blue)

A Cab
B Engine
B C 6 C Frame

3438PEen
Page 23 of 157
CAN terminating resistor, EDC 7 C32 control unit
With the introduction of the new CAN data-bus architecture and the EDC 7 C32 control units, the engine
CAN databus and the OBD CAN data bus can no longer be monitored as before with the 120 Ohm
terminating resistor.
The terminating resistors have been replaced internally in the EDC 7 C32 control unit with switchable
terminating resistors. This means that the engine CAN data bus and/or the OBD CAN data bus can no longer
be tested as before directly on the vehicle management computer (FFR) and/or the AdBlue control unit in the
supply module when the control units are connected. 120 Ohm is measured instead of the expected 60 Ohm,
and the system then incorrectly concludes that faulty wiring or a faulty control unit is present.
Measurements can therefore only be performed when the EDC control unit is disconnected, the ignition is
switched off and the test box is connected or using the oscilloscope (ScopeMeter)!

3438PEen
Page 24 of 157
3 Component description/operation
Information about the components that are not described here can be found in the system description of
the Rail injection for the Common Rail injection system with the control unit EDC 7 (see also Section 7.2).

3.1 Control unit

The EDC 7 control units that are currently in use (hardware/software) are designed for a maximum of
6 cylinders. A second control unit is therefore needed for operating a V-type engine. The two control
units communicate via CAN and operate in “master/slave” mode.
There are 7 Highside output stages in the control unit. 6 of these output stages support the activation of the
injectors, and the final output stage helps to activate the proportional valve (ZME). The main relay (power
supply, terminal 30) is integrated in the control unit.
The engine values are measured via twelve analogue inputs, two frequency inputs and a digital input.
An internal atmospheric pressure sensor is used to monitor the charging pressure sensor. The measured
value of the atmospheric pressure sensor must be the same as the charging pressure when the engine is
idling.
Two versions of the EDC 7 control unit are used at MAN. They ensure the various engine series and
emission classes are covered.
• EDC 7 C3 Use in engines with the emission classes EuroII, EuroIII and EuroIV
• EDC 7 C32 Use in engines with the emission classes EuroII, EuroIII,EuroIV, EuroV and EEV

Socket C Socket B Socket A Socket C Socket B Socket A

EDC 7 C3 EDC 7 C32

Socket A: Engine periphery 57 contacts Socket A: Engine periphery 89 contacts

Socket B: Vehicle connection 16 contacts Socket B: Vehicle connection 36 contacts
Socket C: Injector connection 16 contacts Socket C: Injector connection 16 contacts

The socket assignments of the various control units can be researched in the EDC 7 system description and
in MAN-cats II in the information portal in the system information details under EDC 7 Bosch Overview and
assignment control unit plugs.

3438PEen
Page 25 of 157
3.2 Rail
The Rail is responsible for storing fuel at high pressure. The storage volume of the Rail is designed to
dampen pressure fluctuations that arise due to the fuel transfer of the high-pressure pump and the injection.
As an additional measure for damping pressure fluctuations, throttles are pressed into the high-pressure
sockets for the injector.
The volume of the Rail is calculated so that the pressure can be maintained at a virtually constant level even
when relatively large volumes of fuel are removed. This ensures that the injection pressure remains constant
when the injectors are opened.
The pressure-limiting valve and the Rail pressure sensor are attached to the rail. The term “pressure-limiting
valve” is also referred to as “pressure limiter” in MAN-cats.
At MAN, Rails are/have been fitted that are coordinated with the various versions of the Common Rail
injection system and that are designed for the injection pressures of 1400 bar, 1600 bar and currently
1800 bar.
In the course of technical enhancements, the production processes for the Rail have been converted
from the earlier forged steel (EuroIII) to a tube made of welded steel (EuroIV, EuroV, EEV).
Moreover, the pressure-limiting valve has been integrated into the Rail and so now externally forms a
unit with the rail.

Rail for four cylinders with external

pressure-limiting valve Rail pressure sensor

Pressure-limiting valve

Rail for six cylinders with integrated

pressure-limiting valve
Rail pressure sensor

Note:
There is a risk of confusion due to the identical
appearance of the pressure-limiting valves for
1600 bar and 1800 bar fuel system pressure!
Please therefore ensure when replacing that the
pressure-limiting valve for the correct fuel system
pressure (1600 bar or 1800 bar) is fitted. Pressure-limiting valve
MAN part numbers for pressure-limiting valves
(as of 07/2010):
• 51.10304-0291 for 1600 bar fuel tank system
pressure
• 51.10304-0429 for 1800 bar fuel tank system
pressure
See also Section 6.1, General

3438PEen
Page 26 of 157
Rail for the D2868 (V8) engine with an integrated
pressure-limiting valve and two Rail pressure
sensors and flow restrictors.
The flow restrictors have no function in the D2868
(V8) engine (housing only).
Pressure-limiting valve

Rail pressure sensors

3438PEen
Page 27 of 157
3.3 Injector

The injectors are integrated in the cylinder head and have the same function as the nozzle and nozzle holder
in conventional injection systems. The injector has the following tasks:
• Blind hole nozzle
• Hydraulic servo system
• Solenoid valve
Function of the injectors
The forces required to open and close the nozzle needle cannot be generated just with a solenoid valve. For
this reason, the nozzle needle is controlled indirectly via a hydraulic force booster system. When the solenoid
valve is closed, the same pressure is present in the entire chamber volume as in the rail. The nozzle needle
is pressed into position by a spring.
When the solenoid valve is opened, fuel flows from the valve control chamber into the fuel return line. The
inlet restrictor prevents complete pressure compensation, and the pressure in the valve control chamber
falls. The excess pressure in the chamber volume raises the nozzle needle against the spring force of the
nozzle spring and the injection begins.
The solenoid valve is no longer activated and closes the opening to the fuel return line. As the pressure in
the valve control chamber increases, so does the force applied to the control pistons. As a result, the nozzle
needle is closed and the injection ends.
The injectors are sealed from the combustion chamber by a copper sealing washer.
The injectors are attached with tensioning elements in the cylinder head. Depending on the design of the
injection nozzles, the injectors are suitable for straight/angled installation.

3438PEen
Page 28 of 157
Structure of the injector

1 2 3 4 5 6 7 8 9 10 11

19 18 17 16 15 14 13 12

1 Nozzle needle 12 Spherical seal

2 Nozzle body 13 Valve spring
3 Fuel return 14 Anchor plate
4 Valve plunger 15 Outlet restrictor
5 O-ring 16 Inlet restrictor
6 Valve piece 17 High-pressure connection
7 Valve ball 18 Nozzle spring
8 Tensioning nut 19 Guide bushing
9 Magnetic coil
10 Magnetic core Low pressure
11 Terminal stud High pressure

3438PEen
Page 29 of 157
Overview of new and replacement injectors
At present, there are not only new parts for injectors but also replacement injectors available. They have
been prepared in the context of factory repairs. In the process, all wear parts are replaced by new parts,
regardless of their degree of wear, and all reusable parts are thoroughly cleaned, checked extremely
precisely that they are in full working order, reworked or replaced by new parts.

MAN part numbers, injectors

Use in engine series
New part Replacement part
51.10100-6026 51.10100-9026 D2840
51.10100-6047 51.10100-9047 D2842
51.10100-6049 51.10100-9049 D2876
51.10100-6051 51.10100-9051 D2876
51.10100-6056 51.10100-9056 D2840
51.10100-6058 51.10100-9058 D2842
51.10100-6063 51.10100-9063 D0836
51.10100-6066 51.10100-9066 D0834, D0836
51.10100-6083 51.10100-9083 D0834, D0836
51.10100-6085 51.10100-9085 D0834, D0836
51.10100-6086 51.10100-9086 D0834, D0836
51.10100-6102 51.10100-9102 D2842
51.10100-6114 51.10100-9114 D2868
51.10100-6115 51.10100-9115 D0834, D0836
51.10100-6121 51.10100-9121 D2676
51.10100-6123 51.10100-9123 D2066
51.10100-6125 51.10100-9125 D2066
51.10100-6126 51.10100-9126 D2066
51.10100-6127 51.10100-9127 D2066, D2676

3438PEen
Page 30 of 157
3.4 High-pressure pump
The high-pressure pump is the interface between the low-pressure circuit and the high-pressure circuit of
the fuel system.
Its task is to always provide sufficient compressed fuel in all operating ranges. This also includes the
provision of a fuel reserve that is required for a fast starting procedure and a rapid pressure increase
in the rail.
The high-pressure pump constantly generates the system pressure for the rail.
Two versions of the CP 3.4 high-pressure pump are fitted at MAN with differing low-pressure circuits:
• High-pressure pump, lubricated with engine oil, and with external hot/cold circuit
• High-pressure pump, lubricated with fuel, and with internal hot/cold circuit
It is possible to determine which version of the high-pressure pump and of the low-pressure circuit are fitted
by inspecting the fuel lines in the area of the Fuel Service Center (KSC), among other possibilities. In the
event of possible function and/or leakage checks, it is necessary to take the different versions of the
low-pressure system into account. See Section 3.4.1 for examples of the D20 engine series.

Versions in use (as of 07/10):

• CP3.3 High-pressure pump, lubricated with fuel, 1600 bar fuel system pressure, e.g. for D0836
engines
• CP3.3NH High-pressure pump, lubricated with fuel, 1800 bar fuel system pressure, e.g. for D08
engines with the emission classes EuroV and/or EEV

• CP3.4 High-pressure pump, lubricated with engine oil, 1600 bar fuel system pressure, e.g.
D20 engines with the emission class EuroIII
• CP3.4+ High-pressure pump, lubricated with fuel, 1600 bar fuel system pressure, e.g. D20, D26
engines with the emission class EuroIV
• CP3.4H+ High-pressure pump, lubricated with fuel, 1800 bar fuel system pressure, e.g. for D20,
D26 engines with the emission classes EuroV and/or EEV

3438PEen
Page 31 of 157
 3.4.1 Illustration of the differences in the low-pressure circuit in the D20 engine as an example

3.4.1.1 High-pressure pump, lubricated with engine oil, and with external hot/cold circuit (EuroIII)
Identification: The fuel from the “OUT” connection of the high-pressure pump is fed back to the hand pump.

1 5

1 High-pressure pump, lubricated with 4 Connection from fuel tank

engine oil 5 Connection for return line to fuel tank
2 Connection “OUT” on the high-pressure pump
3 Hand pump

3438PEen
Page 32 of 157
3.4.1.2 High-pressure pump, lubricated with fuel, and internal hot/cold circuit (EuroIV, EuroV, EEV)
Identification: The fuel from the “OUT” connection of the high-pressure pump is returned to the fuel tank
with the leakage volumes from the Fuel Service Center, the Rail (high-pressure accumulator) and the
injectors.

4 3
5

1 High-pressure pump, lubricated with fuel 4 Connection to rail

2 Connection “OUT” on the high-pressure pump 5 Connection to Fuel Service Center
3 Connection cylinder head – return injectors 6 Return line to fuel tank

3438PEen
Page 33 of 157
3.5 Fuel Service Center (KSC)
A Fuel Service Center is used on Common Rail engines.
The KSC combines the fuel pre-filter, the hand primer pump, the main filter and a permanent vent in one
compact component, optionally with or without heating element.
A fuel pressure sensor is mounted on the housing of the Fuel Service Center to monitor the fuel pressure in
the low-pressure circuit. The filter area is around 50% larger and finer than with conventional filters. The fuel
pre-filter can be washed.
There is a 0.3 mm bore at the highest point inside the Fuel Service Center. This permits continuous venting
of the fuel low-pressure system (permanent venting).
Components and connections of the Fuel Service Center:

1 Hand primer pump 7 Connection from the gear pump,

2 Connection to fuel pre-filter (input from tank input in the fine filter
and/or SEPAR filter) 8 Fuel filter heating
3 Connection to high-pressure pump (output) 9 Fuel pressure sensor (B377)
4 Return line to fuel tank 10 Fuel pre-filter
5 Drainage screw or fuel drain screw 11 Connection to gear pump (output)
6 Connection to flame-start system (optional)

3438PEen
Page 34 of 157
 Permanent vent Ø 0.3 mm

A soiled or blocked permanent vent could be one possible cause for relatively long starting
times in the engine.

Fuel Service Center D2868 (V8) engine

D2868 (V8) engine from approx. November 2007

Fuel pressure sensor Fuel filter heating

D2868 (V8) engine from approx. October 2007

In engines up to October 2007, two fuel filter
heating elements were fitted in the Fuel Service
Center

Fuel pressure sensor Fuel filter heating

3438PEen
Page 35 of 157
 3.5.1 Fuel filter replacement
When changing the filter, the same level of cleanliness must be ensured as for exchanging an injector,
for example.

The following procedure must always be observed:

• Unscrew the filter cover of the KSC only until the sealing ring becomes visible. This opens return
bores in the filter housing and the fuel flows back to the fuel tank. Wait until the filter housing
has run empty.
• Open the drain screw on the bottom of the filter housing and allow the rest of the fuel together with
any contamination to drain completely.
Note:
In the D2868LF engines, a drain cock attached to the side of the oil pan must be opened to drain the
remainder of the fuel in the filter housing.

Drain cock
D2868LF

• Open the filter cover fully and remove together with the filter insert.
In the D284x V-type engines, also remove, clean and re-insert the filter housing
• Check that the vent hole for permanent venting is free (clean).
• Close the drain screw at the bottom of the filter or the drain cock (D2868LF) again.
• Important: Do not clean the inside of the filter housing, because there is a great risk that dirt
will pass to the clean side while the filter insert is missing.
• Fit a new filter insert in the filter cover.
• Renew the sealing ring of the filter cover and grease lightly.
• Fit filter cover and screw tight. Tightening torque 25 Nm.
• Using the hand primer pump, pump until resistance can be felt and the overflow valve on the
high-pressure pump opens.

3438PEen
Page 36 of 157
3.6 Pressure-limiting valve (DBV)
The two-stage pressure-limiting valve is mounted on or in the Rail and functions as a safety valve with
pressure limitation.
A drain orifice is opened if the Rail pressure is too high.
In normal operating state, a spring presses the piston into a valve seat so that the Rail remains closed.
The piston is pressed open against the spring by the Rail pressure only if the maximum system pressure
is exceeded.

Common Rail injection Fuel system pressure Opening pressure of the Leakage pressure
system pressure-limiting valve
First generation 1400 bar 1850 to 1950 bar 1750 bar
Second generation 1600 bar 1850 to 1950 bar 1750 bar
Third generation 1800 bar 2100 to 2200 bar 1950 bar

Description of second-generation injection system

If the Rail pressure is too high (>1850 bar), the first piston of the pressure-limiting valve opens (stage 1). As
a result, the pressure can act on a large area of the first piston, which then remains permanently open. The
pressure then also acts on the second piston (stage 2), which opens at 700 - 800 bar due to the larger active
area. After the second stage is triggered, the fuel system pressure is kept constant at approx. 800 - 900 bar.
The engine continues running in emergency mode and the vehicle can be driven to the nearest MAN Service
outlet at reduced full-load volume.
The two-stage pressure-limiting valve closes again only when the engine is switched off and the Rail
pressure falls to below 50 bar.
The pressure-limiting valve is burst open if it does not open quickly enough at an excessively high Rail
pressure.
In order to burst open the pressure-limiting valve deliberately, the proportional valve (ZME) is opened, i.e. set
to maximum supply, and the fuel removal via the injectors is blocked. The Rail pressure therefore increases
abruptly up to the opening pressure of the pressure-limiting valve. If bursting open the valve does not bring
about the desired success, e.g. due to mechanical jamming of the pressure-limiting valve, the engine is
stopped.

Integrated pressure-limiting valve in EuroIV and EuroV

As part of further technical development, the pressure-limiting valve has been integrated in the Rail to
externally form a unit with the rail. This pressure-limiting valve has the same function as the pressure-limiting
valve that is attached externally to the Rail and can also be replaced.

Internal pressure-limiting valve

3438PEen
Page 37 of 157
3.7 Proportional valve (ZME)
The proportional valve and high-pressure pump are matched to one another in production. Therefore always
use a replacement proportional valve for test purposes. Never use the proportional valve of another
high-pressure pump (for example from another vehicle).
A functioning proportional valve controls in a very narrow range, i.e. the % value indicated in the Monitoring
of MAN-cats II only fluctuates by a few tenths of a percentage point at idling speed. If the value jumps by
several % points, it must be assumed that the proportional valve is jamming.
The values of the proportional valve can be checked in the Monitoring under Rail control (proportional valve)
In MAN-cats, the term "Rail control (proportional valve)" is also referred to as Rail control (proportioning
unit).Î Output value Rail pressure controller. See Section 6.2.1.4.

Allocation of replacement proportional valve

Replacement proportional Standard proportional
Use
valve MAN part number valve Bosch part number
D2876, D2868, D2862 with CP3.4 51.12505-0024 0 928 400 543
D2066, D0843, D0836 with CP3.4 51.12505-0027 0 928 400 617
D2876LE with CP3.4
51.12505-0028 0 928 400 658
D2868, D2862 prototype with CP3.4
D2842 LE with CP3.4 51.12902-7023 0 928 400 573
D2840 LF, D2848 LE with CP3.4 51.12902-7024 0 928 400 629
D20, D26 with CP3.4+ 51.12505-0030 0 928 400 662
D20, D26 with CP3.4+ with lubrication
51.12505-0033 0 928 400 705
package
D20, D26 with CP3.4 H+?? 51.12505-0034 0 928 400 737
D0836 LF, LE, LOH, LUH with CP3.4+ with
51.12505-0036 0 928 400 657
anti-corrosion
D0834, D0836 with CP3.3 and filter 51.12505-0037 0 928 400 744
D0836LFG with CP3.3 with lubrication
51.12505-0038 0 928 400 704
package
D2868, D2862 with CP3.4 51.12505-0039 0 928 400 740

Note:
The standard proportional valve is not available as a replacement part.
This means in practice that the workshop checks on the high-pressure pump which standard proportional
valve is fitted, in order to deduce the appropriate replacement proportional valve (see table).
The Bosch part numbers listed in the table will help in finding the correct replacement proportional valve.

3438PEen
Page 38 of 157
3.8 Display messages and check lamps

The display provides information for the driver and also for the workshops and is a part of the instruments.
An overview of the information offered in the display is described below. Due to the intermittent variety of
instrumentation, the explanation will be showed with current high-volume vehicles TGS and TGX.

Example: TGS, TGX – display:

Driving safety is endangered or vehicle damage
is impending!

Malfunction engine
ctrl. unit

A workshop visit is urgently required!

Driving safety could be compromised

Malfunction engine
ctrl. unit

Information, seek workshop assistance

immediately

Coolant temp.
too high

Example: TGS, TGX – check lamps:

Engine fault, red

Central warning light, depending on the

severity of the error it lights up/flashes
yellow or red
A message and the symbol “stop”, “workshop” or
“information” appears in the display if there are
faults in the EDC system. The “central warning
lights” and “engine fault" check lamps are lit and
a warning tone sounds.

Further information with reference to display indications and check lamps as well as the
corresponding operating instructions can be found in the relevant vehicle operating manuals.

3438PEen
Page 39 of 157
3.9 Calling up system faults in the instruments
Call up and display system malfunctions
Faults in the EDC 7 system are stored in the error memory of the control unit and can be read out with
MAN-cats II. Moreover, existing active/passive failures can be requested from the vehicle menu and
viewed in the instrumentation display.

The “Vehicle” menu can be operated (depending on age and equipment of the vehicle) using the buttons
on the instruments, the control panel or the multi-function steering wheel.
Requirements and display in vehicles with multi-function steering wheel
Example: TGS, TGX
1 Select the “Vehicle” menu
Press the button briefly
2 Quit the menu item
Press the button briefly

Quit the “Vehicle” menu

Press and hold down the button
3 Selecting or exiting a menu item or
saving the settings
4 Scroll down in the “Vehicle” menu
5 Scroll up in the “Vehicle” menu

The active button functions in the menu item

appear as symbols on the status bar of the
display.
6 Selected menu, e.g. “Vehicle”
7 Scrolling up in the menu item.
8 Scrolling down in the menu item.
9 Selecting or quitting a menu item or
saving the settings.
10 Quit a menu item or “Vehicle” menu
without saving the settings.
11 Quit “Vehicle” menu

Calling up menu item “Control units” in the

“Vehicle” menu Vehicle
Select the “Control units” menu item by using Driving data
the corresponding buttons on the steering
wheel. Monitoring data

Subsequently, in the “Control units” menu item …

only the malfunctioning electronic systems are Diagnosis
listed.
Control units
If the menu item is selected and there is no
failure then a message appears saying there
are no diagnostic entries.

3438PEen
Page 40 of 157
Illustration of the available error message
• Under “Diagnosis”, select the “EDC” menu Control units
item for the injection system
In the scroll bar to the right of the “EDC” menu
item, one or more error messages may be EDC ACTIVE!
displayed.
Description of the display: 3-03938-08
1 System designation, e.g. EDC
2 Error message “Active!” or “Passive”
Active = There is a current error
Passive = The error is not current but it is
not older than 7 days
3 The mileage at which the error last occurred
4 Error message
Description from left to right:
Priority - SPN (fault location) - FMI
(fault type)

3438PEen
Page 41 of 157
3.10 Identification of hardware and software control units:

Before starting the work, e.g. updating the control unit, use MAN-cats II to identify which hardware and
software is installed in the vehicle.
For this purpose, select the following menu items in the main menu of MAN-cats II:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Control unit identification
These details could be useful for later work, therefore you should make a note of them or print the screen.
• System designation In MAN-cats, the term "System designation" is also referred to as Control
unit name. – Code 0x97:
In the EDC 7 system, the designation of the engine type is stored under System designation.
For example, the change of the engine type could be checked here after flashing the control unit. This
could be the case when changing the engine type from no torque reduction in an OBD error case to an
engine type with torque reduction in an OBD error case.

3438PEen
Page 42 of 157
• MAN item number – code 0x91:
The MAN item number shown here principally corresponds to the control unit installed in the vehicle,
including vehicle adjustment, and is to be used when ordering a spare part, in an update process (flash)
or for service requests.
The MAN item number, e.g. 51.25803-7xxx, represents an assembly from...:
o MAN unfinished part number In MAN-cats, the term "unfinished part number" is also referred to
as MAN unmachined part number. e.g. 51.25803-1xxx
o MAN software number e.g. 51.25803-2xxx
o MAN data record e.g. 51.25803-3xxx
An MAN item number can used to allocate an MAN item number to an EDC software version.
See Section 4.

• MAN unfinished part number In MAN-cats, the term "unfinished part number" is also referred to
as MAN unmachined part number. – code 0x9D:
This item number indicates the hardware used in the EDC 7 control unit.
In order to be able to use it with the basic hardware, a control unit must be flashed with software and a
data file.
The different EDC hardware generations can be identified by the following unfinished part numbers,
for example:

MAN unfinished part number Control units version For software version Comments
51.25803-1000 EDC 7 C3 V24, V25 Stand Alone
51.25803-1006 EDC 7 C3 V23, V30, V31 Stand Alone
51.25803-1800 EDC 7 C3 V20 Master
51.25803-1900 EDC 7 C3 V20 Slave

Stand Alone,
51.25803-1011 EDC 7 C32 V25
Master, Slave
51.25803-1015
EDC 7 C32 V27 Stand Alone
51.25803-1016
Stand Alone,
51.25803-1017 EDC 7 C32 V34, V35
Master, Slave
51.25803-1025
EDC 7 C32 V43, V44 Stand Alone
51.25803-1027

3438PEen
Page 43 of 157
• Withdraw torque limiting In MAN-cats, the term "Withdraw torque limiting" is also referred to as
Withdraw torque limit. – code 0x83:
Use/availability in following software versions:
• From EDC 7 C32 V32
In the course of OBD monitoring, errors are detected that may, in various cases, lead to torque limiting
and activation of the “Exhaust gas aftertreatment” check lamp.
After a successful repair, the workshop has the option of resetting the torque limiting. This represents a
deep intervention into the system and is documented with the date and workshop code (identification
number, fingerprint) in code 0x83!
See also Section 6.2.4.1, Withdraw torque limiting.
• Emission certification In MAN-cats, the term "Emission certification" is also referred to as
Exhaust certification. – code 0x96:
Code 0x96 documents the emission class, e.g. EEV, E4 (EuroIV), etc. and the level of the On-Board
Diagnosis e.g. OBD1, OBD1b or OBD2.
• Manufacturer software version In MAN-cats, the term "Manufacturer software version" is also
referred to as Control unit version number. – code 0x95:
Here, the software version implemented in the control unit is displayed. A change to the software
version, e.g. after flashing the control unit, may be checked here.
Various engine test functions and the structure (illustration) of various Monitoring windows within
MAN-cats II are based on the respective software version.

3438PEen
Page 44 of 157
3.11 D2676LF22 engine with emission class EuroV and EGR
3.11.1 Engine view 1 – front and left

1 2 3 4 5 6

1 and flame glow plug (optional) 5 EDC control unit

2 Flame-start system solenoid valve (optional) 6 Speed sensor, camshaft
3 Charging pressure sensor and intake 7 Fuel pressure sensor
air temperature sensor (B623)
4 Charge air temperature sensor

3438PEen
Page 45 of 157
 3.11.2 Engine view 2 – front

3 4 5
2

1 Proportional valve (Y458) to control the 5 Flame-start system solenoid valve (optional)
EGR adjusting cylinder 6 Charging pressure sensor and intake air
2 Compressed air shut-off valve (Y460) temperature sensor (B623)
for the exhaust gas recirculation (EGR) 7 Intercooler, high-pressure side
3 Check valve housing
4 Flame glow plug (optional)

3438PEen
Page 46 of 157
3.11.3 Engine view 3 – rear

1 Crankshaft speed sensor (B488) 4 Oxygen sensor (B322)

2 Coolant temperature sensor (B124) 5 Coolant service module with coolant filter,
3 Intercooler, low-pressure side including syndicate cartridge*
6 Intercooler, high-pressure side

3438PEen
Page 47 of 157
 3.11.4 Engine view 4 – right-hand side

4 5 6 7

2
8

10

14
11
13 12 15

1 Intercooler, low-pressure side 8 Shut-off/pressure reduction valve (Y496)

2 Pulse valve of the exhaust turbocharger to the low-pressure radiator
(wastegate socket), high-pressure stage 9 Oil pressure sensor (B104)
3 Exhaust gas turbocharger, low-pressure stage 10 Exhaust gas temperature sensor
4 EGR adjusting cylinder 11 Intercooler, high-pressure side
5 Pulse valve of the exhaust turbocharger 12 Oxygen sensor
(wastegate socket), low-pressure stage 13 Exhaust gas turbocharger, high-pressure side
6 Proportional valve (Y458) to control the EGR 14 Charging pressure sensor and intake air
adjusting cylinder temperature sensor (B694) in the
7 Compressed air shut-off valve (Y460) for the low-temperature circuit
exhaust gas recirculation (EGR) 15 Coolant service module with coolant filter,
including syndicate cartridge*

* Note:
As of July 2010, no replacement of the coolant filter and the silicate cartridge is necessary in the context
of standard maintenance or repair work.

3438PEen
Page 48 of 157
3.12 Overview of the sensors for monitoring and controlling the exhaust gas aftertreatment
Below, you will find an overview of possible combinations of sensors and/or actuators which are necessary
for monitoring and controlling the exhaust gas aftertreatment systems, among other functions, and which are
connected to the EDC 7 control unit.
Note: Combinations/vehicles have not been taken into account where the exhaust gas aftertreatment is
carried out with AdBlue.

Exhaust gas differential pressure

Exhaust gas temperature sensor

Exhaust gas relative pressure

Exhaust gas aftertreatment

Engine air flow sensor flap

Oxygen sensor (B322)
(B561, B633, B634)
system

sensor

sensor
(B683)

(B565)

Y398
Engine series and OBD stage

D08 with OBD1 X

PM-KAT
D20, D26 with OBD1 X X
D08 with OBD1 X X X
CRT
D20 with OBD1 X X X
D08 with OBD1 and NOx check X X X
PM-KAT
D20, D26 with OBD1 and NOx check X X X
D08 with OBD1 and NOx check X X X X
CRT
D20 with OBD1 and NOx check X X X X
D08 with OBD2 X X X
PM-KAT
D20, D26 with OBD2 X X X
D08 with OBD2 X X X X
CRT
D20 with OBD2 X X X X
D08 with OBD2 OXI X X
D20, D26 with OBD2 CAT X X

3438PEen
Page 49 of 157
4 Software versions:
Below, you will find an overview of all software versions for the EDC 7 control units that have been in use at
MAN to date.

Date: 07/2010
EDC 7 C3:

MAN software In use since Comments

designation (month/year) Emission class
V 20 12/2001 Master, Slave EuroIII
V 23 02/2002 Stand Alone EuroIII, EuroIV
V 24 04/2003 Stand Alone EuroIII
V 25 12/2003 Stand Alone EuroII, EuroIII
V 30 12/2004 Stand Alone EuroIV
V 31 12/2004 Stand Alone EuroIV
V 32 05/2005 Stand Alone EuroIII, EuroIV

EDC 7 C32:

MAN software In use since Comments

designation (month/year) Emission class
Stand Alone,
V 25 08/2005 EuroIV, EuroV
Master, Slave
EuroII, EuroIII,
V 27 05/2006 Stand Alone
EuroIV, EuroV
Stand Alone,
V 34 06/2007 EuroIV, EuroV
Master, Slave
Stand Alone,
V 35 05/2007 EuroIV, EuroV, EEV
Master, Slave
V 43 06/2008 Stand Alone EuroIV, EuroV, EEV
V 44 11/2008 Stand Alone EuroIV, EuroV, EEV

3438PEen
Page 50 of 157
5 Function parameters (FUP)

A function parameter set is a configuration element in the vehicle data file. It includes one or more
parameters (also from different control units) for activating a specific vehicle functionality and for
adjustment to the current vehicle conditions.
The vehicle data file includes, among other elements, a large number of function parameter sets which
all together describe the configurable functionalities of the vehicle.
Usually a modification of the function parameter sets (FUP) is required only after exchanging the
components, e.g. control unit and/or when making improvements. For this purpose a conversion data
file must be requested. In many cases, this can be done online (MAN-cats II) in the course of campaigns
(Service Information notices) or by ordering from the ESC department competence centre. For the ordering
procedure from the ESC department, see SI 3237SM.

5.1 EDC 7 engine control unit

The overview below is only for information purposes because normally vehicle equipment does not change
in this area. Its purpose is to illustrate the correlation of the function parameters for a specific item of
equipment.
Example: EDC 7
Function parameter designation Item number
EDC control unit with AB sensor fitted 81.25890-0022
Engine brake for D2066 CR engine with EVBec 81.25890-1039
Single-cylinder air compressor in D20/D26 81.25890-1042
Engine speed limit 1 1300 rpm 81.25890-1134
Engine speed limit 2 1400 rpm 81.25890-1135
Fuel filter heating (plug X6/pin 9) 81.25890-1157
Oil level sensing D20 34/40L, engine angle 3° (oil pan glued) 81.25890-1426
Accelerator pedal map D20 version 2 81.25890-1142
Partial vacuum sensor air filter version 70 mbar (air filter housing installation) 81.25890-1510
Exhaust gas temperature sensor AB fitted 81.25890-1611
OBD 1 with NOx check measurement 81.25890-1683
Actuation of compressed air cut-off valve via EDC (mounted to engine) 81.25890-1702
Exhaust gas check via CAN 81.25890-1703
D2066 CR engine, 440 hp, 2100 Nm, Euro 5 81.25890-1718
Electronic Sound Management (ESM) D20 81.25890-1870
Engine catalytic converter V_D20_13 WD 81.25890-1923
Pre-catalytic converter parameters V_D20_13 81.25890-1924
SCR catalytic converter parameters V_D20_13 81.25890-1925
Monitoring of coolant temperature in D08/D20/D26/V8, Euro 4/5 81.25890-1969
Output reduction with OBD error, version 2 81.25890-2117
Flame start with Common Rail 81.25890-2132

3438PEen
Page 51 of 157
A check whether or which function parameters are “fitted” may be carried out as follows with MAN-cats II:

⇒ Main menu Î Vehicle programming Î Information Î Information about vehicle from vehicle
and conversion data file Î Vehicle data file Î from vehicle’s vehicle management computer.
After the vehicle data file has been read out you are given a menu with various groups of
information.

3438PEen
Page 52 of 157
⇒ Select menu item Information functions and press ENTER.
In this menu item, it is also possible to check, if necessary, whether the FUP 81.25890-2135
“RME operation (biodiesel)” has possibly been loaded in the vehicle.

Examples screens

3438PEen
Page 53 of 157
6 Repair notes/diagnosis:

6.1 Troubleshooting/elimination of faults after problems or symptoms:

Problem/symptom/features Vehicles/engines/units affected Cause/Remedy

General
Various problems with the exhaust gas recirculation Engines with exhaust gas recirculation (EGR) Repair instructions for the exhaust gas recirculation
(EGR) module module
• Coolant loss
• Individual parts of the EGR module may be replaced
• EGR shut-off flap sluggish (D28)
• Engine sooted in the area of the EGR shut-off flap
housing (D20)
• Compressed air cylinder for the EGR shut-off flap
is leaking

See SI 169000

If the ignition is switched off and switched on again Trucks and buses/coaches with EDC 7 control unit EDC 7 and FFR begin “afterrunning” when the ignition
shortly afterwards, it may occur in rare cases that the is switched off If, by chance, two specific, brief (50 ms)
engine cannot be started. time windows coincide when the ignition is switched off
and subsequently switched on again, the EDC is
switched off.
This may sporadically lead to the following fault memory
entries:
• FFR 03277 (no engine CAN)
• OBDU 02000 (EDC not on CAN)
Inform the driver that, in unfavourable circumstances, an
“ignition off” followed quickly by “ignition on” may lead to
starting blockages.
Switch the ignition off and on once again

See SI 196602

3438PE
Page 54 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
EDC 7 C3 control unit cannot be flashed; there is a Trucks and buses/coaches with EDC 7 C3 control unit At a control unit temperature above 65 °C, there may be
communication failure with MAN-cats. a data loss during flashing, so the control unit does not
permit flashing at this temperature.
The problem described above currently occurs only with
EDC 7 C3 control units. Therefore please ensure that
these control units are cooled to a temperature of
approx. 60 °C before flashing.
The temperature of the control unit can be displayed in
the Monitoring “Temperatures” of the EDC 7.
See SI 235702

Impurities in the fuel system after the Fuel Service Trucks and buses/coaches with Common Rail engine If the fuel filter is replaced without draining the fuel in the
Center (KSC) KFC beforehand, particles may enter the “clean side”.
Fuel Service Center (KSC)
During repair and maintenance work, please observe
that the fuel must be drained from the KSC before every
fuel filter replacement.
To allow the fuel to be drained fully, not only the shut-off
cock – on the underside – but also the cover of the KSC
must be opened so far that the KSC becomes effective
via the ventilation bore provided in this area.
In this connection, please observe the applicable
maintenance manual for Common Rail engines.
See also Section 3.5.1.

3438PE
Page 55 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
It may be necessary to perform tests with MAN-cats to Vehicles with EDC 7 C32 If required, flash fitted control unit to most recent
be able to do troubleshooting for some error messages EDC control unit with an older software version version to be able to perform tests necessary for
(especially EDC 03776, EDC 03777, EDC 03778, EDC troubleshooting.
03779, EDC 03780 or EDC 03781). It is not always
Most recent software version can only be recognised
possible to perform these tests with control units that
with the MAN part number.
have older software versions.
An additional test device is necessary for some of these
error messages. See SI 334700

Due to the identical appearance of the pressure-limiting Vehicles with D08, D20, D26, D20xxLOH engines and During replacement, always fit the pressure-limiting
valves for 1600 bar and 1800 bar fuel system pressure, 1800 bar fuel system pressure (emission classes EuroV valve for the correct fuel system pressure (1600 bar
in some cases pressure-limiting valves for 1600 bar and EEV) or 1800 bar).
have been fitted in 1800 bar Common Rail injection
Pressure-limiting valve
systems.
See Section 3.2

Replacement engine has been fitted and the EDC Trucks and buses/coaches with Common Rail engine Only the EDC control unit supplied with the replacement
control unit of the removed (old) engine has been engine or attached to it must be used. Only this control
Replacement engine
reused. unit has been optimised for the new engine on the
engine test stand.
Perform pairing of the EDC control unit and the FFR
control unit, activate immobiliser, etc.

3438PE
Page 56 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
Engine replacement has been performed and/or is Trucks and buses/coaches with Common Rail engine For the application for vehicle parameter setting to the
imminent ESC department, the following specifications (shown
below with examples) are necessary:
Which specifications are necessary for the application
for vehicle programming/parameter setting with • Engine type (D2876 LF04)
conversion data file during conversion? • Engine number (5450114093B2E1)
• Part number, EDC control unit: (51.11616.7011)
• Oil pressure sensor (Bosch or AB; refer to the
drawing to see which sensor has been fitted.
Bosch sensor drawing number: 51.27421.0169,
AB sensor drawing number: 51.27421.0163)
• Engine information about the new engine
(D2876/460 hp/2100 Nm/EuroIII)
• Part number of the FFR control unit (81.25805.7015)
• Type of the oil level sensing
– External with oil level sensor control unit
51.25805.6000 or 51.25805.6003
– Can be internally selected as from FFR Step 3;
it would be better to proceed according to the
wiring of the replacement engine cable harness
and to replace the FFR, if applicable.
– No oil level sensing (with oil dipstick)
• Engine angle:
the following can be selected for D28: 1°, 3° and 5°;
the following can be selected for D20: 1° and 3°;
the following can be selected for D08: 0° and 3.2°.
If necessary, specify previous engine angle.

See SI 3237SM for application for vehicle parameter

setting using fax application or
SI 3495SM for an online application for vehicle
parameter setting

3438PE
Page 57 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
The engines mentioned are intended exclusively for Trucks with OBD and the following engines • Apply for manufacturer confirmation for the engine
vehicles with special rights (military, fire service, etc.). conversion from ESC department. An application for
D2066LF17, D2066LF18, D2066LF19, D2066LF20,
These engines do not reduce torque in the event of an vehicle parameter setting is not required. Parameter
D2676LF15, D2676LF16
OBD fault. setting will be internally applied for by the ESC
EDC control unit department due to the confirmation request.
If these engines are used in vehicles without special
rights (e.g. after selling a used vehicle or an inventory • Flash EDC control unit using MAN-cats and
vehicle), it is legally required to specify torque reduction configure vehicle with the conversion data file
in the event of an OBD fault.
• Replace engine model plate.
• The previously fitted model plate of the engine
must be returned to the ESC department
See SI 340800

D0834, D0836
• Error message 03814, control unit switch-off Trucks and buses/coaches with Common Rail engine: Faulty software in the EDC control units
duration (all engine types), D0834LFL50, D0834LFL51, D0834LFL52,
D0834LOH50, D0834LOH51, D0836LFG50, • In the event of error messages 03814 and 03853,
• Error message 03785, clean particulate filter D0836LFL50, D0836LFL51, D0836LFL52, update control unit.
(D0834 only) D0836LOH51, D0836LOH52 • If error messages 03785 are displayed without
• Error message 03853, exhaust gas recirculation, EDC control unit reason, update control unit.
permanent system deviation (all engine types) The
• If the intermediate speed is actuated approx.
term “permanent system deviation” is also referred
200 rpm lower than set, update control unit.
to as residual control deviation in MAN-cats
To avoid damage to a possibly fitted power take-off,
• Intermediate speed control is not actuated correctly
the set intermediate speeds must be checked in the
(D0836LFL52).
Customer-specific parameters menu using MAN-cats
after flashing and parameter setting with the relevant
conversion data files.
See SI 241800

3438PE
Page 58 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
Engine emits white smoke and does not run smoothly D0836LFL40, D0836LFL41, D0836LFL44, Check function of flame-start system.
between 800 and 1100 rpm during warm-up. D0836LOH40,D0836LOH41, D0836LUH40, A leaking solenoid valve on the flame-start system,
D0836LUH41 engines for instance, generates similar fault characteristics.
EDC control unit, flame-start system If flame-start system OK:
Perform update of the EDC 7 control unit
See SI 249800

Intermediate speed control is not actuated correctly. Trucks with D0836LFL51 Common Rail engine faulty EDC control unit software.
EDC control units: If the intermediate speed is actuated approx. 200 rpm
lower than set, perform update of the EDC 7 control unit.
51.25803-7087, 51.25803-7263, 51.25803-7337
See SI 251000

Shaking in partial load range at 1400 to 1600 rpm D0836LOH51, D0836LOH52, D0836LOH53, For some operating conditions, the control unit data
D0836LOH54, D0836LOH55, D0836LOH56, record is not ideal.
D0836LOH57, D0836LOH58, D0836LOH62,
If the customer complains about the stated problem,
D0836LOH63 engines
perform update of the EDC 7 control unit
EDC 7 control unit
See SI 276600

If the error messages 03850, 03851 or 03853 have been Trucks and buses with EuroIV engine (Euro4) D0834CR These error messages are entered into the fault memory
entered into the fault memory, the EGR adjusting or D0836CR with EGR control not only if a faulty EGR adjusting cylinder is present,
cylinder is replaced without further inspection. but also if it is incorrectly adjusted.
EGR adjusting cylinder 51.08150-0044
Therefore, in order to back up and empty the fault
memory of the complete vehicle, please also carry out
the checking and adjusting steps described in the SI.
See SI 276700

3438PE
Page 59 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
Error message 03837 is stored in the fault memory. This D0836LFL53, D0836LFL54, D0836LFL55 engines 1. The oxygen sensor really has a short-circuit to earth,
error message indicates that the oxygen sensor has a so this SPN is stored permanently in the fault
Oxygen sensor, EDC control unit
short-circuit to earth. memory.
2. The oxygen sensor does not have a short-circuit to
earth; however, the fault memory entry is triggered
when the engine speed is briefly "pushed" below
the idling speed. Due to the resulting brief smoke
emission the oxygen sensor is considered
“defective”, and SPN 03837 is sporadically
stored in the fault memory.
To ascertain whether the fault is permanent or just
sporadic, it may be helpful to read out the frequency
counter using MAN-cats.
1. In the case of a permanent fault memory entry,
proceed as described in the T18 repair manual.
2. In the case of a sporadic fault memory entry,
perform update of the EDC 7 control unit
See SI 295400

OBD fault memory entries P2bAE or P2bAD Engines D0834LFL53, D0834LFL54, D0834LFL55, NOx check too sensitive. The fault memory entries are
D0834LOH52, D0834LOH53 unfounded
OBD, EDC 7 control unit Perform update of the EDC 7 control unit
See SI 301700

• Error messages 03868, 03871, 03872 Buses/coaches, TGL, TGM and X-types with D0836 Plausibility test of the temperature sensors for charge
engine air, coolant and EDC control unit can be defective in
• During diagnosis with MAN-cats II, the exhaust gas vehicles with long downtimes.
temperature sensor and the ambient temperature EDC 7 C32 control unit
sensor are classified as faulty from a coolant Perform update of the EDC 7 control unit
temperature of 70 °C. See SI 310200

3438PE
Page 60 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
1. Error messages EDC 03785, EDC 03929 and/or Trucks or buses/coaches with D08 EuroV (Euro5) 1. Check which exhaust back pressure sensor is
EDC 03930 for vehicles with D08 EuroV (Euro5) engine or EEV (Enhanced Environmentally Friendly installed.
engine or EEV Vehicle) A ServiceDesk case with the following information
2. Error messages EDC 03929 for vehicles with Exhaust back pressure sensor, EDC control unit, must be created if an AB exhaust back pressure
D0836LFL63 engine operation with FAME sensor is fitted:
Sensor AB and EDC 03785, 03929 and 03930
3. Error messages EDC 03929 for vehicles with
D0836LFL53, D0836LFL54 or D0836LFL55 engine After you have received a solution, function
parameter 81.25890-1610 must be ordered using
an application for vehicle parameterisation. A copy
of the ServiceDesk case must be attached to the
application for vehicle parameterisation.
2. Do not carry out any repair attempts for this
fault memory entry. Delete EDC and OBD fault
memories first. A ServiceDesk case with the
following information must be created if the
fault appears again after a test drive:
D0836LFL63 and EDC 03929 engines
3. Check if the function parameter for operation with
FAME (81.25890-2135) is present in the vehicle
data file. Use the vehicle data file in the FFR:
Vehicle programming Î Information Î Information
about vehicle from vehicle and conversion data file
Î Vehicle data file Î from vehicle’s vehicle
management computer.
⇒ If the function parameter is present but the
vehicle is not operated with FAME, function
parameter 81.25890-2135 must be removed
with an application for vehicle parameterisation.

3438PE
Page 61 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy

⇒ A ServiceDesk case with the following

information must be created if the function
parameter is present and the vehicle is
operated with FAME:
EDC 03929 and FAME operation

Problem in engines D0836LFL60, D0836LFL63: Vehicles with engines D0836LFL60, D0836LFL63, Software error in the EDC control unit.
D0834LOH60, D0834LOH61
• Error message 03929 Perform update of the EDC 7 control unit
EDC control unit
• Vehicles move off poorly See SI 343500
Problem in engines D0834LOH60 and D0834LOH61:
Vehicles do not idle smoothly

Vehicles do not always start without problems at low Bus/coach and bus/coach chassis with D0836LOH60, Perform update of the EDC 7 C32 from software
temperatures. D0836LOH61, D0836LOH64 or D0836LOH65 engine version 43 to software version 44
EDC 7 C32 control unit See SI 357700

D2066, D2676
One of the following EDC error messages is shown in TGA with D20xx engine The electrically sensed tolerances of the components
the instrument display: are arranged too narrowly for the mechanical tolerances
EDC 7 control unit
• EDC 03778 (Rail pressure: Leakage in overrun An update is necessary for the EDC 7 control unit in
conditions) order to enlarge the sensed tolerance range.
• EDC 03779 (Rail pressure: Leakage during If the error messages in the display are still present
quantity compensation) after flashing, the component which is triggering the
error message must be determined and replaced.
• EDC 03780 (Rail pressure: High controller
output when idling) See SI 182402

3438PE
Page 62 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
Oil emerges at the injector cable harness in the area of D20 and D26 engine series Poor crimping and/or plug contact is not flush with the
the plug of the control unit injector cable harness, so engine oil is being sucked
Injector cable harness
into the injector cable harness (capillary effect).
Replace leaking injector cable harnesses.
See SI 266300

At low ambient temperatures, error message is/entry TGA, TGS, TGX with D2066LF23, D2066LF24 or The control unit's plausibility check of the exhaust
EDC 03811, even though the exhaust gas temperature D2676LF12 engines temperature is not working correctly
sensor before the AdBlue mixer is operating correctly.
EDC control unit Perform update of the EDC 7 control unit
See SI 273000

Error message EDC 03785 (exhaust gas differential Bus/coach with D2066LOH26, D2066LOH27, Software error in the control unit
pressure too high) D2066LOH28, D2676LOH26, D2676LOH27 engine
Clear the EDC fault memory.
If the error message appears again after this, please
open a ServiceDesk case, stating the engine type and
error message 03785.
See SI 327500

D2876
Engine does not run smoothly, unusual engine noise, Trucks and buses/coaches with D2876LF12, Wear at the nozzle seat of the injectors
smoke development, performance deficiency D2876LF13, D2876LOH20, D2876LOH21 Common Rail
engines up to engine number xxx0532002xxxx inclusive • Check build status of the EDC control unit and
injection system, and update to the latest version
Rail, injector, EDC 7 control unit if necessary.
• Always (even in connection with other repairs)
ensure the correct allocation of the injectors – Rail –
EDC control unit.
See SI 132400

3438PE
Page 63 of 157
 Problem/symptom/features Vehicles/engines/units affected Cause/Remedy
Excessive fuel consumption, performance complaints TGA with D2876LF12, D2876LF13 engine Programme version of the control units is not yet the
most recent version.
EDC 7 control unit (Common Rail) 51.25803-7057 and
51.25803-7056 Update of EDC 7 control unit necessary
See SI 159300

3438PE
Page 64 of 157
6.2 Extensions/process descriptions in MAN-cats II
6.2.1 Monitoring

6.2.1.1 Overview of the input variables that work with replacement values in the event of a defect
categorisation
A sensor or signal path is categorised as faulty if an error is present over a defined period of time. Until the
defect categorisation is completed, the system (control unit) uses the most recent value that was detected as
valid.
When defect categorisation is completed, generally after the ignition is switched off and on again, the system
switches to a replacement value or substitute function stored in the control unit.
In the case of most of these faults, the signal is monitored constantly. If the sensor or signal path is detected
as intact over a defined period of time, the defect categorisation is cancelled and the system switches to the
actually present value.
You will find below an overview of the input variables/sensors that are applied (assigned) with replacement
values in the control unit and are disclosed in the appropriate Monitoring windows in MAN-cats II and/or must
be taken into account during troubleshooting:
Example of defect categorisation

3438PEen
Page 65 of 157
A meaningful diagnosis with MAN-Cats II is possible only when the engine is running. The following
examples are based on tests with the engine running and at standstill, an engine temperature greater than
30 °C and an ambient air temperature of approx. 20 °C.
In the event of deviating general conditions and actual values that may therefore differ, the values displayed
in MAN-cats II must be compared with the measured values documented in the repair manual T18.

6.2.1.2 Monitoring Temperatures

• Coolant temperature
o Setpoint for an engine at operating temperature: approx. 80 to 90 °C
On the subject of the coolant temperature and its effects, see also Section 2.3.6.3 – Engine
protection functions.
o Replacement value: 100.4 °C, in D20, D26 engine with AdBlue system
• EDC internal temperature
In the EDC 7 control unit there is a temperature measuring unit, which detects the temperature load on
the control unit.
o It displays the currently prevalent internal temperature in the control unit.
(Control unit temperatures over approx. 90 °C may lead to data loss)
• EDC internal temperature, max.
o The maximum temperature reached in the control unit is displayed.
• EDC internal temperature, min.
o The minimum temperature reached in the control unit is displayed.

3438PEen
Page 66 of 157
• External air temperature via CAN
The ambient air temperature (outside air temperature) is provided for the EDC 7 control unit by the
vehicle management computer (FFR) via the engine control CAN data bus.
o The current ambient air temperature is displayed.
The displayed value should be identical to the value in the FFR Monitoring.
An ambient air temperature higher than 30 °C may lead to a torque reduction; see also Section
2.3.6.3, Engine protection functions.
o Replacement value: 20 °C in D20, D26 engine with AdBlue system
• Charge air temperature ahead of engine (optional)
EuroIV, EuroV engines: The charge air temperature sensor is integrated into the charging pressure
sensor and is fitted ahead of the exhaust gas recirculation.
The EGR rate can be checked for plausibility in connection with the sensor Charge air temperature
ahead of cylinder intake and the different temperatures of the two sensors.
o Setpoint: 0 °C to 60 °C; the current charge air temperature is displayed:
o Replacement value: 40 °C, in D20, D26 engine with AdBlue system
• Charge air temperature ahead of cylinder intake
This charge air temperature sensor is fitted in the intake pipe ahead of the cylinder intake. No charge
air temperature sensor is fitted in the D20, D26 engine with AdBlue system.
The EGR rate can be checked for plausibility in connection with the sensor “Charge air temperature
ahead of engine” and the different temperatures of the two sensors.
o Setpoint: 0 °C to 60 °C
The current charge air temperature ahead of the cylinder intake is displayed
o Replacement value: 40 °C
• Oil temperature via CAN
The oil temperature is provided for the EDC 7 control unit by the vehicle management computer (FFR)
via the engine control CAN data bus. Only the replacement value is displayed, but not in the defect
categorisation mode!

o Setpoint: 0 °C to 60 °C
The current engine oil temperature is displayed. The displayed value should be identical to the
actual value in the FFR Monitoring.
o Replacement value: 40 °C
• Fuel temperature
Note: The fuel temperature sensor is currently (07/2010) not fitted in vehicle engines. In these engines,
only the replacement value is displayed, but not in the defect categorisation mode!
o Setpoint: 20 °C to 90 °C
Only the replacement value is displayed in vehicle engines.
o Replacement value: 40 °C

3438PEen
Page 67 of 157
6.2.1.3 Monitoring pressures

• Charging pressure
The displayed charging pressure is a relative pressure in relation to the atmospheric pressure. The
EDC 7 control unit therefore outputs the pressure differential between the measured value read out
in the charging pressure sensor and the value in the atmospheric pressure sensor. See item
“Atmospheric pressure” in the same Monitoring window
o Setpoint: approx. - 30 mbar to 50 mbar (engine idling, depending on engine type)
For other setpoints, see “Minimum load pressure reference values” list (SI 301100)
In the case of an intact exhaust turbocharger system, a partial vacuum can only be measured in the
intake pipe during idling. Excess pressure always sets in at higher speeds.
If this is not the case, check the following components:
− Wastegate socket (jams, carbonised)
− Exhaust turbocharger (cracks, carbonisation (SI 277800), general damage, damage to the vanes
of the turbine wheel and/or compressor wheel, axial play and radial play)
Note on charging pressure check:
The maximum possible charging pressure can only be determined on an incline when fully loaded after
approximately 1 min in this condition.
• Atmospheric pressure
The currently prevalent atmospheric pressure is displayed, measured by the atmospheric pressure
sensor integrated into the EDC 7 control unit.
• Oil pressure
The engine oil pressure is measured by the EDC 7 control unit, but does not have any influence on the
calculations in the EDC 7 control unit. The measured value is provided to the vehicle management
computer (FFR) via the engine control CAN data bus.
o Setpoint: 1.0 bar to 6 bar (with engine idling).
o Replacement value: 1 bar in D20, D26 engine with AdBlue system

3438PEen
Page 68 of 157
• Recorded fuel pressure ahead of the filter In MAN-cats, the term "Recorded fuel pressure ahead
of the filter" is also referred to as registered fuel pressure before the filter.
The fuel pressure on the low-pressure side is displayed, measured by the fuel pressure sensor (B377)
in the Fuel Service Center (KSC).
Note: The fuel pressure sensor was originally not fitted in the D08 engine series.
o Setpoint: 5.0 bar to 6.0 bar (with engine idling and new and/or unsoiled filter).
Note:
At starting speed, a fuel pressure of over 3.0 bar should be generated within
2 seconds in an intact system.
o Replacement value: 1.0 bar in D20, D26 engine with AdBlue system
In the case of a fuel pressure greater than 8 bar, the fault memory entry 00094-1 is stored in the EDC
7 control unit, and in the case of a fuel pressure lower than 2.5 bar, the fault memory entry 00094-2 is
stored.
Information about possible causes and their remedy can be found, among other places, in the system
description about the accumulator injection for the Common Rail injection system with the EDC 7
control unit (see also Section 7.2).

3438PEen
Page 69 of 157
6.2.1.4 Monitoring Rail control (proportional valve) In MAN-cats, the term "Rail control
(proportional valve)" is also referred to as Rail control (proportioning unit).

• Fuel pressure setpoint (Rail pressure)

o The setpoint for the Rail pressure specified by the control unit and calculated for the current
operating state is displayed.
• Fuel pressure actual value (Rail pressure)
The actual value for the fuel pressure in the rail, measured via the Rail pressure sensor (B487, B514),
is displayed.
o Setpoint: 200 bar to 540 bar (with engine idling).
o Replacement value: 750 bar to 860 bar, depending on the engine speed and the requested
injection volume
• Rail pressure monitoring
The status of the Rail pressure monitoring is displayed and, in the event of a fault, notes about the type
of the present fault in the high-pressure system are supplied.
The following status messages are possible:
o No fault In MAN-cats, the term "no fault" is also referred to as no defect.
o Rail pressure too high
o Rail pressure too low
o Rail pressure above limit value
o Negative deviation
o Positive deviation
o Leak detected in coasting mode In MAN-cats, the term "Leak detected in coasting mode" is also
referred to as Leakage detection in coasting.
o Leak based on volume report In MAN-cats, the term "Leak based on volume report" is also referred
to as Leakage from quantity balance.
o Excessively high-pressure pump supply volume when idling In MAN-cats, the term "Excessively
high-pressure pump supply volume when idling" is also referred to as High pressure pump delivery
quantity excessive in idling.

3438PEen
Page 70 of 157
• Who limits Rail pressure (SPN) In MAN-cats, the term "Who limits Rail pressure (SPN)" is also
referred to as which limits Rail pressure (SPN).
In the event of a fault, the Rail pressure (fuel setpoint) may be restricted under certain circumstances,
in order to protect the engine from possible further damage.
o The error message (SPN) which triggered the restriction of the Rail pressure is displayed.
• Rail pressure controller starting value In MAN-cats, the term "Rail pressure controller starting
value" is also referred to as Output value Rail pressure controller.
The activation value for the Rail pressure controller, i.e. the proportional valve, is displayed under this
item. An internal control-unit value (duty cycle) is shown, which cannot be measured at any output in
that form.
However, experience shows that this value is extremely helpful in assessing the governing of the Rail
pressure and the integrity of the fuel system. The value is never static, because this is part of the
control circuit for the Rail pressure.
o Setpoint at idling speed: lower than 6 %
Note: A value over 6 % for the idling speed indicates a possible leak in the fuel system.
Opening the proportional valve wider is an attempt to compensate for this.
If the output value for the Rail pressure controller jumps up several percentage points,
the cause could possibly be that the proportional valve is jammed.
Another possible cause could be a sluggish high-pressure pump.
• Status of the pressure-limiting valve In MAN-cats, the term "Status of the pressure-limiting valve"
is also referred to as Status of pressure relief valve.
The status of the Monitoring for the pressure-limiting valve is displayed here. In the event of a fault,
more detailed information is provided about the type of the fault.
The following status messages are possible:
o Normal
o Pressure > maximum pressure
o Pressure drop detection, step 1
o Pressure drop detection, step 1 with averaging
o Pressure drop detection, step 2 In MAN-cats, the term "Pressure drop detection, step 2" is also
referred to as Pressure stop detection step 2.
o Undefined flag is set
o Forced opening requested In MAN-cats, the term "Forced opening requested" is also referred to as
Push open requested.
o Not open after forced opening In MAN-cats, the term "Not open after forced opening" is also
referred to as after pushing open, not opened.
o Open

3438PEen
Page 71 of 157
6.2.1.5 Monitoring Engine speeds

• Speed (crankshaft)
The speed measured by the crankshaft speed sensor (B488), integrated in the flywheel casing, is
displayed. The term “speed sensor” is also referred to as “engine speed sensor” in MAN-cats.
Attention:
In the event of a faulty crankshaft speed sensor, the replacement value from the camshaft speed is
displayed here. See also “Operating mode of the speed sensors” item in the same Monitoring window.
• System speed from camshaft
A speed from the speed sensor (B489) on the camshaft is displayed here. This is an engine speed
calculated by the control unit and not the actual speed of the camshaft.
• System speed
The engine speed calculated by the control unit from the crankshaft speed and/or the camshaft speed
is displayed.
• Synchronisation of the speed sensor
During the starting procedure, the signals from the camshaft and crankshaft speed sensors are
synchronised or, if only one sensor signal is available, the control unit switches to operation with
just one sensor.
The following status messages are possible:
o Initialisation state: The control unit attempts to synchronise both speed sensor signals.
o Synchronisation successful (normal state): The synchronisation procedure is complete.
o Synchronisation with one speed sensor only: The control unit has switched to operation
with one speed sensor.
o Engine stop: The control unit detects an engine standstill.

3438PEen
Page 72 of 157
• Operating mode of the speed sensors
In the case of a fault, additional information about the speed signals is displayed here.
The following status messages are possible:
o No fault
o Camshaft signal faulty
o Crankshaft signal faulty
o Both sensors defective
• Status of engine speed detection
Various status messages about the engine speed detection, which provide additional information
for troubleshooting in the event of a fault, are displayed.
The following status messages are possible:
o Normal state
o Initialisation state: search for increments
o Engine is at a standstill or is rotating too slowly
o Valid crankshaft signals found, but no gap yet. Phase still unknown
o Gap found. Phase still unknown
o Start only with crankshaft. EDC finds ignition TDC through test injections and evaluation of the
engine speed acceleration, i.e. if there is no increase in the rotational acceleration after the
injection, the injection at 360 crankshaft degrees was incorrect (load change TDC)
o Check of angle difference between camshaft and crankshaft
o Increment system (crankshaft) defective; start attempt only with camshaft
o Final state: operation with camshaft only
o Condition for avoiding faults in uneven engine running or failure of the engine
o Final operation with crankshaft only
o Sensors are being ignored
o Engine speed evaluation without function

3438PEen
Page 73 of 157
6.2.1.6 Monitoring Engine values

• Start main injection

The start of the main injection is displayed in crankshaft degrees.
Depending on the operating state, values up to – 15.6 crankshaft degrees before TDC are possible.
• Current injection volume
The injection volume currently used for the operating state is displayed in milligrams per cylinder
stroke.
• Volume limit
The currently maximum possible injection volume is displayed, which is limited by various characteristic
curves or maps.
• Volume limit by EDC fault
This item shows the currently maximum permissible injection volume, resulting from possible EDC error
messages. This is designed to prevent impermissible operating states and to warn the driver (torque
limiting).
If no error message is available which requires a limiting of the injection volume, the maximum value
of 410 mg/stroke is displayed.
• Who limits injection volume (SPN)
The EDC error message (SPN) is displayed which leads to volume limiting under the “Volume limiting
by EDC fault” item.

3438PEen
Page 74 of 157
• Engine mode
The controller function of the EDC control unit that is currently responsible for the calculation of the
present injection volume is displayed. See “Current injection volume” item in this Monitoring window.
The following status messages, among others, are possible:
o CAN decoder
o Intermediate speed controller
o Volume limit
o Maximum-speed governor In MAN-cats, the term "Maximum-speed governor" is also referred to as
Top-speed governor.
o Idling speed governing
o Start module
o Zero quantity by monitoring logic
o Specification by remote control
o Volume control through fuel pressure peak limiting In MAN-cats, the term "Volume control through
fuel pressure peak limiting" is also referred to as Quantity influenced by peak fuel pressure limit.
o Volume control by forcing the pressure-limiting valve open In MAN-cats, the term "Volume control
by forcing the pressure-limiting valve open" is also referred to as Quantity influenced by opening
of pressure limiter.
• Relative torque
The percentage value of the torque/injection volume at the current engine speed is displayed,
based on the value of the full-load map.
• Load operation: Positive value
• Coasting: Zero value or negative value
• Current torque limitation
The function or the map on which the current engine speed limiting is based is displayed.
The following status messages, among others, are possible:
o Basic map incl. overheating protection
o Smoke map
o Volume increase after start In MAN-cats, the term "Volume increase after start" is also referred to
as Quantity increase after start.
o Limit by system fault
o Active PTO
• Engine speed from maximum-speed governor In MAN-cats, the term "Engine speed from
maximum-speed governor" is also referred to as Speed from top-speed governor.
The maximum governed speeds specified for this engine are displayed. The displayed value is
dependent on the version of the maximum-speed governor currently activated in the control unit.
See following item.
• Maximum-speed governor In MAN-cats, the term "Maximum-speed governor" is also referred to
as Limit speed control.
The version of the maximum-speed governor that is currently in use is displayed. The respective stored
speeds are output under the Engine speed from maximum-speed governor item. In MAN-cats, the term
"Engine speed from maximum-speed governor" is also referred to as Speed from top-speed governor.
The following maximum-speed governor statuses are possible:
o EDC internal maximum-speed governor In MAN-cats, the term "EDC internal maximum-speed
governor" is also referred to as EDC internal top-speed governing.
o Basic speed governor, CAN specification In MAN-cats, the term "Basic speed governor,
CAN specification" is also referred to as Basic governing specification CAN.
o Limit, cold engine
o Limit due to fault
o Increase, CAN specification In MAN-cats, the term "Increase, CAN specification" is also referred to
as Raise CAN specification.

3438PEen
Page 75 of 157
 o Increase, CAN specification limited In MAN-cats, the term "Increase, CAN specification limited" is
also referred to as Raise CAN specification limited.
o Limiting of active PTO In MAN-cats, the term "Limiting of active PTO" is also referred to as Limit
active power take-off.
• Exhaust gas recirculation flap (only in vehicle with EGR)In MAN-cats, the term "Exhaust
gas recirculation flap" is also referred to as Exhaust gas recirculation system flap.
The actuation ratio for the EGR adjusting cylinder (non-controlled) and/or for the proportional valve for
controlling the adjusting cylinder (position-controlled or lambda-controlled) is displayed as a percentage
o Setpoint, non-controlled EGR: 0 % or 100%
o Setpoint, position-controlled or lambda-controlled EGR: 0 % up to 100%
• Exhaust gas recirculation actual flap position (only in vehicle with EGR) In MAN-cats, the term
"Exhaust gas recirculation actual flap position" is also referred to as Exhaust gas recirculation flap actual
position.
The current position of the EGR shut-off flap (non-controlled) is displayed
A dry-reed contact in the EGR adjusting cylinder (uncontrolled) monitors whether the EGR shut-off flap
is open or closed.
The following status messages are possible:
o Open
o Closed in end position In MAN-cats, the term "Closed in end position" is also referred to as Closed
in limit position.
• Exhaust gas recirculation status (only in vehicle with EGR) In MAN-cats, the term "Exhaust gas
recirculation status" is also referred to as Exhaust gas recirculation system status.
It is displayed here whether the exhaust gas recirculation is enabled.
In the event of a fault or under specific general conditions, additional information is output here through
status messages.
The following status messages are possible:
o enabled
EGR disabled because:
o Distance to smoke map too low
o Dynamic engine operation In MAN-cats, the term "Dynamic engine operation" is also referred to as
Dynamic engine mode.
o Engine too hot
(coolant temperature above approx. 95 °C, depending on engine type)
o Engine too cold
(coolant temperature below approx. 60 °C, depending on engine type)
o Charge air temperature too high
(charge air temperature above approx. 70 °C, depending on engine type)
o Charge air temperature too low
(charge air temperature below approx. 10 °C, depending on engine type)
o Coolant temperature sensor defective In MAN-cats, the term "Coolant temperature sensor
defective" is also referred to as Cooling water temperature sensor defective.
o Engine brake active
o Regeneration request active
o Atmospheric pressure too low
o Engine in accelerated warm-up
o Injection volume too low
o defective output stage
o EGR disabled due to sooting In MAN-cats, the term "EGR disabled due to sooting" is also referred
to as EGR blocked because of soot buildup.

3438PEen
Page 76 of 157
6.2.1.7 Monitoring Cylinders
The Cylinders monitoring window supplies information to the smooth running control function (adaptive
cylinder balancing control). This function is designed to ensure even engine running, especially when idling.
This is achieved with an individual adjustment of the fuel volume for each cylinder.
Note: The smooth running control function is only active when idling and/or in the engine series D08 and
D2868 (V8) it is always inactive.

• Cylinder shut-off status

EDC 7 provides the possibility of switching off injectors of individual cylinders and/or cylinder banks
when idling and in gearbox neutral position. At cold temperatures, this leads to reduced white-smoke
emissions.
The following status messages are possible:
o active
o not active
This functionality is currently not used in vehicle engines, so the status should be “not active” at this
item.
• Speed (crankshaft)
The speed measured by the crankshaft speed sensor (B488), integrated in the flywheel casing, is
displayed.
• Current injection volume
The injection volume currently used for the operating state is displayed in milligrams per cylinder
stroke.

3438PEen
Page 77 of 157
• Fuel volume correction, cylinder 1 to n
Under these items, the deviations determined by the control unit (increase or reduction in injection
volume) from the actual injection setpoint volume per cylinder calculated for this operating state are
displayed for you.
On the basis of these values, it is also possible to reach conclusions about the engine status in
connection with the compression test and the rev-up test. Information about evaluating the displayed
values can be found on the following page.
Note: The Smooth running control function is not active in the engine series D08 and D2868 (V8):
you will therefore not see any deviations under this item, but only static values (0 mg/stroke).

3438PEen
Page 78 of 157
Assessment of the Cylinders Monitoring window:

Reduction of the fuel

volume (-)

Increase of the fuel Increase of the fuel

volume (+) volume (+)

Attention:
For fault-memory entries 00651 to 00656 and if there is a short-circuit in the control unit injector current path,
the injectors of a bank (output stage in the control unit) are deactivated and the bars of the relevant injectors
go to the same negative values in the smooth running control.

Sample analysis:
• If Cylinder 2 is performing poorly, the adjustment amount for Injector 2 is therefore increased.
• If the engine still does not run evenly, the adjustment amount for injector 4 is also increased.
• To ensure that the engine does not then run too quickly, the injection volumes for cylinders 1 and 5 are
reduced in the present example.

It is therefore possible to detect a group of injectors where two injectors demonstrate an added volume (+)
and one injector, and in some cases even two injectors, demonstrate a reduced volume (-).
In this combination (+ + -), the first cylinder, i.e. cylinder 2, is the one performing poorly.
However, this does not mean that the injector in the second cylinder is defective, but simply means that, in
our example, the second cylinder is the one with the poorer performance. Other checks are necessary to be
able to determine what is the cause of the present fault, because the cause for poor performance may also
be a lack of fuel or poor compression, for example. Therefore always perform a compression test and a
rev-up test.

3438PEen
Page 79 of 157
If greater deviations are displayed, the user should check in the “Status of the injectors” Monitoring window
whether any physical faults may be present in the path of an injector.
Further information about possible causes and their remedy can also be found in the system description
about the accumulator injection for the Common Rail injection system with the EDC 7 control unit
(see also Section 7.2).

3438PEen
Page 80 of 157
6.2.1.8 Monitoring Status of the injectors

Diagnostic functions of the control unit continuously monitor the output stages (banks) of the injectors. This
makes it possible to detect physical defects such as line discontinuities or short-circuits in the control unit –
cable harness – injector current path. Depending on the fault type and categorisation, the injection of the
affected cylinder, and in individual cases the injection of an output stage (two cylinders) is disabled.
A faulty “injector” should also be noticeable in the Cylinders Monitoring window.
• Line discontinuity at cylinder In MAN-cats, the term "Line discontinuity at cylinder" is also
referred to as Line interruption on cylinder.
The cylinder that is categorised as defective (current path) is displayed.
• Electrical fault (short circuit)
The cylinder that is categorised as defective (current path) is displayed.

3438PEen
Page 81 of 157
6.2.1.9 Monitoring Status information
In vehicles without OBD:

In vehicles with OBD:

3438PEen
Page 82 of 157
• Battery voltage
The supply voltage measured by the EDC control unit is displayed.
• EDC operating hours
The total operating hours of the EDC control unit are displayed (time duration from “Ignition on” and
engine speed greater than 0 rpm)
• Engine operating hours from EDC
The total operating hours measured in the EDC control unit, in which the engine speed was greater
than 0 rpm, are displayed.
• Operating mode
The current operating mode of the EDC engine control is displayed.
The operating mode is determined by the central monitoring logic of the control unit.
The following operating modes are possible:
o Function initialisation
(Takes place after “switch-on” of the control unit)
o Normal operation
o Afterrunning terminal 15 off
(The engine has been switched off. The control unit remains in an afterrunning phase until the
engine reaches standstill and all corresponding control-unit checks have been completed)
o Afterrunning test
(A test of the overvoltage detection function is carried out) In MAN-cats, the term "Afterrunning test"
is also referred to as After-run test.
o Store afterrunning
(The control unit has been switched off and is in afterrunning mode. In MAN-cats, the term "Store
afterrunning" is also referred to as After-run save. Any errors and values learned during operation
are stored in the control-unit memory)
o Switch-off mode main relay
(In this operating mode, the switch-off of the control unit is organised via the internal main relay
(HRL) and the Monitoring of the main relay)
o Engine diagnosis
(An engine test, e.g. the compression test, has been requested by an external testing unit
(e.g. MAN-cats II))
o Wait mode
(In this operating mode in vehicles with master/slave control units, one control unit waits until the
partner control unit has been programmed)
o Copy appl. RAM to Flash
(The control unit copies data and/or data is copied to Flash via MAN-cats II)
• EDC status
The current status of the EDC is displayed
The following status messages are possible:
o Status undefined
o Normal before start
o Normal start
o Normal after start
o Post-operation
o Electronic diesel control in emergency running
o Disengaging

3438PEen
Page 83 of 157
• Starter control
The current status of the logic module for the starter control in the EDC 7 control unit is displayed.
The logic module is responsible, for example, for the generation of start and stop requests or for start
aborts. This module receives the start request from the vehicle management computer (FFR) or from
the compression test.
The following status messages are possible:
o No start active
o Normal start active
o EMERGENCY start active
o Normal start successfully completed
o Normal start cancelled, ring gear turning
o Normal start cancelled, max. number of dummy shifts exceeded
(Dummy shift: starter has not engaged in ring gear)
o Max. normal start time exceeded
o Normal start cancelled, overtemperature detected by IER
(IER: this refers to the integrated mechanical relay (IMR))
o Normal start cancelled, withdrawal of request by vehicle management computer
o Normal start cancelled, “terminal 15” off during start
o Normal start cancelled, engine speed information missing
o Normal start cancelled, engine stop button pressed
o Emergency start completed successfully
(Emergency start EDC: engine start with accelerator pedal pressed)
o Emergency start cancelled, engine speed information missing
o Emergency start cancelled, withdrawal of request by vehicle management computer
o Emergency start cancelled, terminal 15 off during start
o Engine stop button pressed

• Status of starter relay activation

The status of the internal control-unit module for controlling the output stage for the integrated
mechanical relay (IMR) on the starter is displayed.
The following status messages are possible:
o no activation
o Constant activation
o Cyclic activation (normal start)
o Cyclic activation (emergency start)
(In the event of this status message, an overload protection for the integrated mechanical relay
(IMR) is bridged)

The following Monitoring items are also displayed in vehicles with OBD and exhaust gas recirculation.
• Status of the MIL (MIL = malfunction indicator lamp)
The current status of the check lamp for the exhaust gas aftertreatment (MIL) is displayed

or
The following status messages are possible:
o No request
o Continuous light
o Flashing light

3438PEen
Page 84 of 157
• MI lamp lit for (hours (h))
The total activation duration of the check lamp for the exhaust gas aftertreatment is displayed in hours.
• MIL request by
The control unit displays which system/control unit initiated the request for activation of the check lamp
for the exhaust gas aftertreatment.
The following systems/control units are possible:
o EDC or master
o EDC7C32 slave
o AdBlue System, Bosch
(Control unit in AdBlue supply module)
o Lamp test

3438PEen
Page 85 of 157
6.2.1.10 Monitoring specifications/messages from FFR

All values/information shown in this Monitoring window are provided for the EDC 7 control unit by the
vehicle management computer (FFR) via the engine control CAN data bus.
• Intermediate speed control setpoint of vehicle management computer
The setpoint engine speed requested by the vehicle management computer is displayed, e.g. the
values in the respectively programmed ZDR parameter records for PTOs (ZDR = intermediate speed
control).
Upon activation of the pre-programmed working speed via the stalk switch using the “MEM” button,
the setpoint e.g. for the TG truck series is 1200 rpm.
• Max. governed speed In MAN-cats, the term "Max. governed speed" is also referred to as
Max. limit control shut-off speed.
In normal operation (without activation of the intermediate speed control by the FFR), a setpoint of
approx. 8000 rpm is displayed. The term “intermediate speed control” is also referred to as
“intermediate speed controller” in MAN-cats.
Upon activation of an intermediate speed control, e.g. by approaching the working speed for a PTO,
the currently permissible maximum governed speed for this operating state is displayed.
With regard to intermediate speed controls, see also SI 68102 (interface for intermediate speed control
on FFR) and SI 71302 (interface on customer-specific control module (KSM).
• Driver's request
The driver's request volume requested by the FFR is displayed as a percentage, resulting from the
accelerator-pedal position.

3438PEen
Page 86 of 157
• Engine torque
The engine torque currently requested by the FFR is displayed
• Idle speed set speed
The idling setpoint speed requested by the vehicle management computer is displayed.
• Pedal travel
The driver's request volume requested by the FFR is displayed as a percentage, resulting from the
accelerator-pedal position.
• Max. injection volume
The volume limiting requested by the vehicle management computer (i.e. the maximum permissible
injection volume) for the current operating state is displayed.
The reasons for the volume limiting may include the activation of a PTO or, in vehicles with TipMatic,
torque limiting during gear shifts, for example.
o Setpoint: Approx. 150 to 400 mg/stroke (in normal operation, depending on engine type)
• Parking brake
The status information for the parking brake is displayed, showing whether the brake is engaged or not
engaged. This information is used to signal a vehicle standstill to the EDC control unit.
• Zero quantity request
This Monitoring item is used to display whether the engine brake has been activated. Using this
information, the EDC control unit reduces the injection volume to 0 mg/stroke (zero volume) when
the engine brake is active.
The following status messages are possible:
o No request
o Engine brake active
• Engine stop request
The control unit displays whether an engine stop request is present in the FFR.
The following status messages are possible:
o No request
o Request active
• FFR status
The current status is displayed regarding the request for an engine start from the FFR to the
EDC control unit.
The following status messages are possible:
o No start request
o Request normal start
o Request emergency start (EDC)
• EDC stand-alone operation
This point displays whether the EDC control unit is communicating with the vehicle management
computer (FFR) via the CAN data bus or the EDC control unit is working autonomously
(stand-alone operation), e.g. due to a missing CAN message.
The following status messages are possible:
o Normal operation
o Ignore vehicle management computer specifications (stand-alone)
Engine running at idling speed only

3438PEen
Page 87 of 157
• Intermediate speed control parameter set
This item displays which intermediate speed control (ZDR) is requested by the vehicle management
computer and, in connection with this, which parameter set is activated in the EDC 7 control unit.
The following status messages are possible:
o ZDR 0 to ZDR 7
o Setpoint: ZDR 0
• EDR parameter set
This item displays which maximum-speed governor mode is requested by the vehicle management
computer and, in connection with this, which parameter set is activated in the EDC 7 control unit. The
setpoint speed stored in the respective parameter set is displayed under the “Max. governed speed”
item in this Monitoring window. In MAN-cats, the term "Max. governed speed" is also referred to as
Max. limit control shut-off speed.
The following status messages are possible:
o EDR 0 to EDR 5
• Idling speed governor parameter set
This item displays which idling-speed governor is requested by the vehicle management computer and,
in connection with this, which parameter set is activated in the EDC 7 control unit. Each parameter set
contains parameters for a cold, a warm and a hot engine. The setpoint speed stored in the respective
parameter set is displayed under the “Idle speed set speed” item in this Monitoring window.
The following status messages are possible:
o Parameter set 0
o Parameter set 1
o Parameter set 2

3438PEen
Page 88 of 157
6.2.1.11 Monitoring Charging pressure governing system (EuroIV, EEV)

• Charging pressure setpoint

The charging pressure setpoint calculated by the control unit for the current operating state is
displayed, based on various input variables such as speed, charge air temperature, current charging
pressure, engine brake request, state of the wastegate capsule, etc.
• Charging pressure
The displayed charging pressure is a relative pressure in relation to the atmospheric pressure. The
EDC 7 control unit therefore outputs the pressure differential between the measured value read out in
the charging pressure sensor and the value in the atmospheric pressure sensor.
o Setpoint: approx. - 30 mbar to 50 mbar (with engine idling).
For other setpoints, see list of Minimum load pressure reference values (SI 301100)
In the case of an intact exhaust turbocharger system, a partial vacuum can only be measured in the
intake pipe during idling. Excess pressure always sets in at higher speeds.
If this is not the case, check the following components:
− Wastegate socket (jams, carbonised)
− Exhaust turbocharger (cracks, carbonisation (SI 277800), general damage, damage to the vanes
of the turbine wheel and/or compressor wheel, axial play and radial play).
Note on charging pressure check:
The maximum possible charging pressure can only be determined on an incline when fully loaded after
approximately 1 min in this condition.

3438PEen
Page 89 of 157
• Atmospheric pressure
The currently prevalent atmospheric pressure is displayed, measured by the atmospheric pressure
sensor integrated into the EDC 7 control unit.
• Control difference charging pressure In MAN-cats, the term "Control difference charging
pressure" is also referred to as Control differential charge air pressure.
The charging pressure differential is displayed between the current charging pressure and the charging
pressure calculated by the control unit.
• Activation pulse duty ratio for charging pressure governing system The term “charging pressure
governing system” is also referred to as “boost pressure control” in MAN-cats
The duty cycle is displayed, based on the charging pressure setpoint for the activation of the pulse
valve of the exhaust turbocharger and the connected wastegate capsule.
Fixed values are displayed, for example, if an invalid value is provided from the charging pressure
sensor, or an engine brake request or a permanent system deviation is present.
o Setpoint: 0 % to 100 %
Note:
0 % = Minimum charging pressure
100 % = Maximum charging pressure
• Changeover
The current operating mode of the charging pressure governing system is displayed.
A changeover from the operating mode Closed-loop control (standard) to the operating mode
Open-loop control is carried out, for example, if the control difference is outside the specified range,
the EGR shut-off flap is opened or the charging pressure falls below a specified value in the current
operating state.
The changeover is reversed immediately if the conditions for closed-loop control are fulfilled again.
The following operating modes are possible:
o Closed-loop control
o Open-loop control
• Operating mode charging pressure governor In MAN-cats, the term "Operating mode charging
pressure governor" is also referred to as Operating mode charge air pressure governor.
The current operating mode of the charging pressure governing system is displayed.
The following operating modes are possible:
o Open-loop control
o Closed-loop control
o Disengaging
o Normal operation
• Permanent system deviation charging pressure governor In MAN-cats, the term "Permanent
system deviation charging pressure governor" is also referred to as Permanent system deviation
charge air pressure governor.
The control unit displays whether a permanent system deviation is present.
If a permanent system deviation is present, a fixed value, for example, for the activation of the pulse
valve of the exhaust turbocharger and the connected wastegate capsule is output.
The following status messages are possible:
o No
o Yes

3438PEen
Page 90 of 157
6.2.1.12 Monitoring Exhaust gas aftertreatment
In vehicles without AdBlue, EGR only:

In vehicles with AdBlue:

3438PEen
Page 91 of 157
Differences in Exhaust gas aftertreatment Monitoring window:
In vehicles without AdBlue system, and only exhaust gas recirculation (illustration, top), the exhaust gas
differential pressure sensor signal voltage is displayed at the marked position, whereas in vehicles with
AdBlue system (illustration, bottom) the exhaust temperature after exhaust gas aftertreatment is displayed
at the marked position.
• Exhaust temperature before exhaust gas aftertreatment
The values of the exhaust gas temperature sensor (B561, B633) are displayed, which is fitted before
the PM catalytic converter (EGR system) or at the AdBlue mixer ahead of the SCR catalytic converter
(AdBlue system).
The measured value is provided for various monitoring tasks within the EDC and acts, for example, as
a protection against thermal overload in the exhaust manifold, the exhaust turbocharger, the exhaust
silencer, etc. via the quantity limit function.
o Setpoint:
o Replacement value: 100 °C, in D20, D26 engine with AdBlue system
Note:
In vehicles with the D2868LF (V8) engine, this exhaust gas temperature sensor is connected to the
Master control unit. The slave control unit receives the required value from the master control unit.
• Exhaust gas differential pressure, particulate filter (only in vehicle with EGR) In MAN-cats, the term
"Exhaust gas differential pressure particulate filter" is also referred to as Exhaust differential pressure
particulate filter.
Depending on the exhaust gas aftertreatment, PM catalytic converter or CRT filter (bus/coach), the
measured pressure of the exhaust is displayed as compared to atmospheric pressure (exhaust gas
relative pressure sensor) and/or the pressure drop at two measuring points (exhaust gas differential
pressure sensor).
If the specified value is exceeded, a regeneration of the catalytic converter/filter (PM or CRT) is
initiated. See also “Regeneration status” item in this Monitoring window.
o Setpoint: less than 60 mbar (PM catalytic converter), see following notes
Approx. 150 mbar (CRT filter) in D08 engine
Approx. 200 mbar (CRT filter) in D28 engine
o Replacement value: 15 mbar (PM catalytic converter)
Notes:
In normal operation, the exhaust gas differential pressure at breakaway speed should be under
60 mbar. Hold breakaway speed for approx. 5 s until this condition stabilises. With values over
60 mbar, the catalytic converter/filter may be blocked or a developing blockage may be present.
In a vehicle with a PM catalytic converter and at engine standstill, a setpoint of 0 to 3 mbar should be
displayed. In the event of a negative measured value, the cause may possibly be a defective exhaust
gas relative pressure sensor or the pressure measuring line to the exhaust gas relative pressure
sensor (hairline cracks).
See also SI 3306AT
• Exhaust gas differential pressure sensor signal voltage (only in vehicle with EGR)
(only in vehicles without AdBlue system, EGR only)
The signal voltage currently output by the exhaust gas relative pressure sensor (PM catalytic converter)
and/or the exhaust gas differential pressure sensor (CRT filter) is displayed. This value corresponds to
the value displayed under the “Exhaust-gas differential pressure particulate filter” item.
o Setpoint: 0.40 V to 0.70 V (when idling)
• Exhaust temperature after exhaust gas aftertreatment
(only in vehicles with AdBlue system)
The values of the exhaust gas temperature sensor (B634) are displayed, which is fitted in the tailpipe of
the exhaust gas silencer.
o Setpoint:
o Replacement value: 100 °C, in D20, D26 engine with AdBlue system

3438PEen
Page 92 of 157
• Differential pressure threshold for cleaning the particulate filter (only in vehicle with EGR)
• Particulate filter status (only in vehicle with EGR)
The status of the various regeneration modes, neutral or forced regeneration and any initiated
measures are displayed.
The following status messages are possible:
o No action
o Neutral
o Forced regeneration
o Forced regeneration action close exhaust gas recirculation flap
(The engine brake flap is opened and the EGR shut-off flap is closed, and a time delay for the start
of the forced regeneration action level 1 is started.)
o Forced regeneration action idling speed
o Forced regeneration action coasting
o Forced regeneration action regeneration level 1
(The EGR shut-off flap is closed, the injection start is corrected and/or the Rail pressure is raised)
o Forced regeneration action regeneration level 2
o Forced regeneration action diagnosis
• Regeneration status (only in vehicle with EGR)
The control unit displays the status whether a and/or which regeneration level is currently being
performed.
The following status messages are possible:
o Regeneration no activity
o Regeneration level 1
o Regeneration level 2
• Control engine air flow sensor flap
It is displayed which status is requested for the engine brake flap by the EDC control unit.
The following status messages are possible:
o Open
o Closed
• Exhaust gas recirculation flap (only in vehicle with EGR)In MAN-cats, the term
"Exhaust gas recirculation flap" is also referred to as Exhaust gas recirculation system flap.
The actuation ratio for the EGR adjusting cylinder (non-controlled) and/or for the proportional valve for
controlling the adjusting cylinder (position-controlled or lambda-controlled) is displayed as a percentage
o Setpoint, non-controlled EGR: 0 % or 100%
o Setpoint, position-controlled or lambda-controlled EGR: 0 % up to 100%

3438PEen
Page 93 of 157
• Exhaust gas recirculation flap actual position (only in vehicle with EGR)
The current position of the EGR shut-off flap (non-controlled) is displayed
A dry-reed contact in the EGR adjusting cylinder (uncontrolled) monitors whether the EGR shut-off flap
is open or closed.
The following status messages are possible:
o Open
o Closed in end position In MAN-cats, the term "Closed in end position" is also referred to as Closed
in limit position.

• Exhaust gas recirculation status (only in vehicle with EGR) In MAN-cats, the term
"Exhaust gas recirculation status" is also referred to as Exhaust gas recirculation system status.
It is displayed here whether the exhaust gas recirculation is enabled.
In the event of a fault or under specific general conditions, additional information is output here through
status messages.
The following status messages are possible:
o enabled
EGR disabled because:
o Distance to smoke characteristic map too small
o Dynamic engine operation In MAN-cats, the term "Dynamic engine operation" is also referred to as
Dynamic engine mode.
o Engine too hot
(coolant temperature above approx. 95 °C, depending on engine type)
o Engine too cold
(coolant temperature below approx. 60 °C, depending on engine type)
o Charge air temperature too high
(charge air temperature above approx. 70 °C, depending on engine type)
o Charge air temperature too low
(charge air temperature below approx. 10 °C, depending on engine type)
o Coolant temperature sensor defective In MAN-cats, the term "Coolant temperature sensor
defective" is also referred to as Cooling water temperature sensor defective.
o Engine brake active
o Regeneration request active
o Atmospheric pressure too low
o Engine in accelerated warm-up
o Injection volume too low
o defective output stage
o EGR disabled due to sooting In MAN-cats, the term "EGR disabled due to sooting" is also referred
to as EGR blocked because of soot buildup.

3438PEen
Page 94 of 157
• Charging pressure
The displayed charging pressure is a relative pressure in relation to the atmospheric pressure. The
EDC 7 control unit therefore outputs the pressure differential between the measured value read out in
the charging pressure sensor and the value in the atmospheric pressure sensor.
o Setpoint: approx. - 30 mbar to 50 mbar (engine idling
For other setpoints, see “Minimum load pressure reference values” list (SI 301100)
In the case of an intact exhaust turbocharger system, a partial vacuum can only be measured in the
intake pipe during idling. Excess pressure always sets in at higher speeds.
If this is not the case, check the following components:
− Wastegate socket (jams, carbonised)
− Exhaust turbocharger (cracks, carbonisation (SI 277800), general damage, damage to the vanes
of the turbine wheel and/or compressor wheel, axial play and radial play)
Note on charging pressure check:
The maximum possible charging pressure can only be determined on an incline when fully loaded after
approximately 1 min in this condition.
• Atmospheric pressure
The currently prevalent atmospheric pressure is displayed, measured by the atmospheric pressure
sensor integrated into the EDC 7 control unit.
• Current injection volume
The injection volume currently used for the operating state is displayed in milligrams per cylinder
stroke.
• Speed (crankshaft)
The speed measured by the crankshaft speed sensor (B488), integrated in the flywheel casing,
is displayed.

3438PEen
Page 95 of 157
6.2.1.13 Monitoring of exhaust gas recirculation
Depending on the engine type, the emission class (Euro...) or the level of the exhaust gas emission
monitoring (OBD1/OBD2), no or varying Monitoring windows are provided for the topic of exhaust
gas recirculation.
Non-controlled exhaust gas recirculation:

Position-controlled exhaust gas recirculation:

3438PEen
Page 96 of 157
Position-controlled and lambda-controlled exhaust gas recirculation:

• Exhaust gas recirculation

The type of exhaust gas recirculation which is fitted/configured in this vehicle is displayed.
The following status messages are possible:
o Non-controlled
o Position-controlled
o Lambda-controlled EGR with subordinate position control
• Exhaust gas recirculation system
The display shows how the exhaust gas recirculation system is classified by the EDC control unit. This
information is used, among other functions, for the allocation of the actuation logic and the actuation
signals for the exhaust gas recirculation.
The following classifications are possible:
o Not ready for operation
o Ready for operation

3438PEen
Page 97 of 157
• Actual position of exhaust gas recirculation flap
The display shows how the current position of the EGR shut-off flap is classified by the EDC control
unit. This information is used, among other functions, for the allocation of the actuation logic and the
actuation signals for the exhaust gas recirculation.
The following classifications are possible:
With non-controlled exhaust gas recirculation
o Open
o Closed
With position- or lambda-controlled exhaust gas recirculation
o Not ready for operation
o Ready for operation
• Adapted zero position of the EGR flap
The display shows how the zero position of the EGR shut-off flap learned in an automatic calibration
mode is classified by the EDC control unit.
In the case of the “invalid” classification, please check the setting of the EGR adjusting cylinder and the
displacement sensor and readjust if necessary.
The following classifications are possible:
o Invalid
o Valid
• Exhaust gas recirculation lock
The current status of the exhaust gas recirculation is displayed.
If conditions are prevalent which set the status of the exhaust-gas recirculation to “blocked”, you will
find additional information with regard to a possible cause under the “Exhaust-gas recirculation lock
status” item in this Monitoring window.
The following status messages are possible:
o Enabled
(The exhaust gas recirculation is enabled in a fault-free system from approx. 60 °C coolant
temperature)
o Blocked
• Exhaust gas recirculation lock status
Any shut-off conditions detected by the system are displayed which have led to the blocking of the
exhaust gas recirculation module. Several shut-off conditions are possible at the same time and are
displayed, if necessary.
The following shut-off conditions are possible:
o Enabled
o Distance to smoke map too low
o Dynamic engine operation In MAN-cats, the term "Dynamic engine operation" is also referred to
as Dynamic engine mode.
o Engine too hot
(coolant temperature above approx. 95 °C, depending on engine type)
o Engine too cold
(Coolant temperature below approx. 60 °C, depending on engine type)
o Charge air temperature too high
(charge air temperature above approx. 70 °C, depending on engine type)
o Charge air temperature too low
(Charge air temperature below approx. 10 °C, depending on engine type)
o Coolant temperature sensor defective In MAN-cats, the term "Coolant temperature sensor
defective" is also referred to as Cooling water temperature sensor defective.
3438PEen
Page 98 of 157
 o Engine brake active
o Regeneration request active
o Atmospheric pressure too low
o Engine in accelerated warm-up
o Injection volume too low
o Defective output stage
o EGR disabled due to sooting In MAN-cats, the term "EGR disabled due to sooting" is also referred
to as EGR blocked because of soot buildup.
• Neutral voltage
The voltage value measured by the control unit via the displacement sensor attached to the EGR
adjusting cylinder for the current actual position of the EGR shut-off flap is displayed.
If the measured value is classified as defective, a replacement value is provided.
o Setpoint: 0.5 - 0.9 V – when idling
with a correctly adjusted EGR adjusting cylinder (1.25 ± 25 mm pre-load), setpoint approx. 0.7 V

1 Voltage
2 Travel of the EGR adjusting cylinder
1

2
Notes:
In the event of a measured value greater than approx. 4.94 V, it is extremely probable that a
discontinuity is present; if the measured value is lower than approx. 0.5 V, it is extremely
probable that a short-circuit is present.
• Nominal position exhaust gas recirculation flap
The setpoint specified by the control unit as the actuation signal for the EGR adjusting cylinder
(non-controlled) and/or for the proportional valve for controlling the EGR adjusting cylinder
(position-controlled or lambda-controlled) is displayed as a percentage.
o Setpoint, non-controlled EGR: 0 % or 100%
o Setpoint, position-controlled or lambda-controlled EGR: 0 % up to 100%
Actual position exhaust gas recirculation flap The current actual position of the EGR shut-off flap is
displayed.
The open or closed EGR shut-off flap is detected in the case of non-controlled exhaust gas
recirculation via a dry-reed contact in the EGR adjusting cylinder or via a displacement sensor attached
to the EGR adjusting cylinder in the case of position-controlled or lambda-controlled exhaust gas
recirculation.
o Setpoint, non-controlled EGR: 0 % or 100%
o Setpoint, position-controlled or lambda-controlled EGR: 0 % up to 100%
If no current actual position of the EGR shut-off flap is displayed, the possible cause in the case
of position-controlled or lambda-controlled exhaust gas recirculation may be either a defective
proportional valve (Y458), a defective compressed air shut-off valve (Y460) or its activation.
During a check, also pay attention to electrical and pneumatic lines.

3438PEen
Page 99 of 157
 See also SI 276700, Section 3 in the case of trucks and buses/coaches with D0834 or D0836 engines
In the case of the D08 engine with the emission class EuroIV or the emission class EEV and OBD 1,
the compressed air shut-off valve (Y460) is fitted on the frame side!
• EGR flap defect status
A detected defect classification in the feedback path regarding the position of the EGR shut-off flap is
displayed
The following status messages are possible:
o No fault
o Too high
o Too low
o No signal present
o Not plausible
o Short-circuit to positive
o Short-circuit to earth
o Not defined
• Exhaust gas recirculation system output stage
The classification of the activation path (output stage) of the exhaust gas recirculation system by the
EDC control unit is displayed.
The following status messages are possible:
o OK
o Fault
In the case of the status message “Fault”, the closed-loop control of the EGR shut-off flap is
switched off.
Note:
If the status message “Fault” is displayed, the possible cause in the case of position-controlled or
lambda-controlled exhaust-gas recirculation may be either a defective proportional valve (Y458), a
defective compressed air shut-off valve (Y460) or its activation. During a check, also pay attention to
electrical and pneumatic lines.
EGR permanent system deviation It is displayed whether a permanent system deviation has been
detected by the EDC control unit. A permanent system deviation is output if the setpoint to be achieved
by the system in the relevant operating state is not achieved in a defined period of time.
The following status messages are possible:
o Yes
o No
• Operating mode of lambda-controlled EGR
It is displayed in which operating mode the lambda-controlled exhaust gas recirculation is working.
Depending on the operating mode, various characteristic curves, maps, etc. are used for forming the
setpoint for activating the EGR shut-off flap.
The following status messages are possible:
o Closed control loop
o Open control loop

3438PEen
Page 100 of 157
• Charge air temperature ahead of cylinder intake
This charge air temperature sensor is fitted in the intake pipe ahead of the cylinder intake.
The EGR rate can be checked for plausibility in connection with the sensor “Charge air temperature
ahead of engine” and the different temperatures of the two sensors.
o Setpoint: 0 °C to 60 °C
The current charge air temperature ahead of the cylinder intake is displayed
o Replacement value: 40 °C
• Coolant temperature
o Setpoint for an engine at operating temperature: approx. 80 to 90 °C
On the subject of the coolant temperature and its effects, see also Section 2.3.6.3 – Engine
protection functions.
o Replacement value: 100.4 °C, in D20, D26 engine with AdBlue system

3438PEen
Page 101 of 157
6.2.1.14 Monitoring Lambda values

• Oxygen sensor in exhaust pipe

It is displayed whether the installation of the oxygen sensor (in the exhaust pipe) was classified as valid
by the EDC control unit.
The detection of whether the oxygen sensor is fitted in the correct location, i.e. in the exhaust pipe,
is carried out under specific engine operating conditions. The check verifies whether the measured
lambda value is above a defined specification.
The following status messages are possible:
o Installed
o Not installed
• Oxygen sensor system
The system displays how the oxygen sensor system was classified by the EDC control unit on the
basis of the prevalent general conditions.
On the basis of this classification, the start value, for example, is defined for activating the output
stage for the oxygen sensor heating.
The following classifications are possible:
o Not ready for operation
o Ready for operation

3438PEen
Page 102 of 157
• Oxygen sensor
The current status of the oxygen sensor is displayed
In vehicles without AdBlue, the heating of the oxygen sensor is enabled in this way. In vehicles with
AdBlue, a CAN data bus message it is sent to the AdBlue control unit in the supply module to enable
the heating in the NOx sensor.
The following status messages are possible:
o Enabled
(The oxygen sensor heating is enabled from approx. 60 °C coolant temperature)
o Not enabled
• Lambda measurement
The system displays how the currently measured oxygen sensor signal and so the oxygen sensor is
classified.
The following classifications are possible:
o Not ready for operation
o Ready for operation
• Lambda actual value (displayed value/100)
The currently measured lambda value is displayed.
o Setpoints: approx. 400 - 700 When idling
approx. 120 At full load
approx. 2000 When coasting (no engine brake operation)
Requirement: Coolant temperature greater than 70 °C, waiting time approx. one second after every
load change.
Display: 3K = 3000
• Oxygen sensor temperature
The current operating temperature of the oxygen sensor is displayed
To allow an optimal detection of the lambda value, the oxygen sensor must be maintained at a constant
temperature. The oxygen sensor temperature is detected via the temperature-dependent internal
resistance of the probe.

3438PEen
Page 103 of 157
• Oxygen sensor correction factor (displayed value/1000)
The correction factor stored in the EDC control unit is displayed. This factor is read determined in every
“coasting phase” while observing specified general conditions, and it is stored during control-unit
after-running whenever the EDC 7 control unit is switched off.
The correction factor acts as an influencing factor on the increase of the measuring accuracy for the
measurement of the oxygen concentration via the oxygen sensor.
o Setpoint: approx. 1010
o Tolerance range: approx. 890 to 1140
If the value of the correction factor is greater than 1140 and a fault-memory entry 03898 is present,
the following causes are possible:
− Plug connection to the oxygen sensor damaged or
− Oxygen sensor worn
Note:
If the correction value is approx. 8000 or -8000, the oxygen sensor must be taught.
See also Section 6.2.4.2, Initialisation of the lambda correction factor.
Display: 5K = 5000
• Mark-to-space ratio for activation of heater output stage
The setpoint specified by the control unit as an activation signal for the heating of the oxygen sensor is
displayed as a percentage.
Note:
In the case of a setpoint greater than 60 %, the fault-memory entry 03855 (oxygen sensor system) is
entered. Check plug contacts and lines to the oxygen sensor.
The enabling of the output stage for the lambda probe heating is performed from a coolant temperature
of approx. 60 °C and it can be checked under the “Lambda probe” item.
• Coolant temperature
o Setpoint for an engine at operating temperature: approx. 80 to 90 °C
On the subject of the coolant temperature and its effects, see also Section 2.3.6.3 – Engine
protection functions.
o Replacement value: 100.4 °C, in D20, D26 engine with AdBlue system
• Exhaust temperature before exhaust gas aftertreatment
The values of the exhaust gas temperature sensor (B561, B633) are displayed, which is fitted before
the PM catalytic converter (EGR system) or at the AdBlue mixer ahead of the SCR catalytic converter
(AdBlue system).
The measured value is provided for various monitoring tasks within the EDC and acts, for example, as
a protection against thermal overload in the exhaust manifold, the exhaust turbocharger, the exhaust
silencer, etc. via the quantity limit function.
o Setpoint:
o Replacement value: 100 °C, in D20, D26 engine with AdBlue system
Note:
In vehicles with the D2868LF (V8) engine, this exhaust gas temperature sensor is connected to the
Master control unit. The slave control unit receives the required value from the master control unit.

3438PEen
Page 104 of 157
6.2.2 Engine test function
In order to support Service, test routines have been implemented in the EDC 7 control unit as well as
troubleshooting on actuators, which reduce and/or limit the effort involved in troubleshooting the fuel system
(low-pressure and high-pressure sides) and on mechanical components (engine compression) of the engine.
In recent years, more and more engine test functions have been developed, so that today (07/2010) the
following tests are available, depending on the software version for the EDC 7 control unit:

• Actuator test • Cylinder shut-off test

• Compression test • High-pressure test
• Rev-up test • Pressure-limiting valve open test
(In MAN-cats also referred to as
opening test for pressure-limiting valve.

For better evaluation of the damage pattern/symptoms, you should always carry out the following tests
in this order:
• Compression test
• Rev-up test
• Monitoring window Cylinders
• High-pressure test (only as from vehicles with a control unit as from software version EDC 7 C32
V34.1)

Further information about engine test functions can also be found in the system description on accumulator
injection for the Common Rail injection system with EDC 7 control unit (see also Section 7.2).

3438PEen
Page 105 of 157
6.2.2.1 Actuator test
Available in MAN-cats II:
• as from EDC 7 C32 software version 30
Description:
The actuator test makes it possible to actuate different actuators for test purposes, to gather acoustic
(“click-clack test”) or visual (visual check) feedback about the function of the actuator.
The actuation period and the selection of the components to be actuated are defined by MAN-cats II.
Depending on the test it is possible in different cases to enter various values in the tester, in order to set – for
example – a desired duty cycle or pressure for test purposes.
The “Actuator test” menu item is offered by MAN-cats II only if suitable actuators, for example for
exhaust-gas recirculation, are fitted.

Note:
If no visual check of the EGR shut-off flap is possible despite activation by MAN-cats II, the possible cause
in the case of position-controlled or lambda-controlled exhaust gas recirculation may be either a defective
proportional valve (Y458), a defective compressed air shut-off valve (Y460) or its activation. During a check,
also pay attention to electrical and pneumatic lines.
See also SI 276700, Section 3 in the case of trucks and buses/coaches with D0834 or D0836 engines.

In the case of the D08 engine with the emission class EuroIV or the emission class EEV and OBD 1,
the compressed air shut-off valve (Y460) is fitted on the frame side!

3438PEen
Page 106 of 157
6.2.2.2 Compression test
Available in MAN-cats II:
• as from EDC 7 C32 software version 20
Description:
The compression deviations of the individual cylinders are determined with the help of the compression test.
The starter must be actuated via the ignition lock until the control unit has measured the speeds at BDC
(bottom dead centre) and shortly before TDC (top dead centre) for all cylinders.
The speed briefly reaches its minimum at the TDC of each cylinder. This is the point of maximum
compression.
General conditions for test
• Battery 100% charged
• Engine at operating temperature, greater than 75 °C
• Warm up the vehicle by driving; do not let it warm up whilst stationary
• After completing the compression test, switch off the ignition without fail (otherwise the control unit
remains in test mode!)

Evaluation of the Compression test:

Experience shows that the values of the

following cylinder (in ignition sequence)
are slightly excessive. This must be
regarded as normal.

Low speed:
Good: Maximum difference ± 2 rpm Value too low:
Unclear: to ± 5 rpm; incorrect valve Problem at cylinder 4
clearance possible Maximum difference: 5 rpm compared
Defective: The difference greater than to previous and/or following cylinder
5 rpm compared to previous
and/or following cylinder
(valve damage, piston ring
Cylinders that are conspicuous and/or are
damage, etc. possible)
classified as faulty during the compression
In the event of cylinder damage, test indicate a large positive correction
the values of the other cylinders volume in the fuel correction volumes for
an have greater variability. the smooth running control function.
Always repair only the poorest See example on the following page
cylinder!

3438PEen
Page 107 of 157
An example is shown below (Cylinders Monitoring window), which represents fuel correction volumes for an
engine with an insufficient compression on cylinder 4.

During the compression test, cylinder 4 was detected with

values outside the permissible range, which indicates poor
compression.
As a result of the poor compression, cylinder 4 therefore
demonstrates a large positive fuel correction volume.
Cylinders with poor compression always have a positive
correction volume.

Note: If the compression test indicates mechanical damage, this must be remedied before
it is possible to come to a conclusion about the injectors with the rev-up test.

3438PEen
Page 108 of 157
6.2.2.3 Rev-up test
Available in MAN-cats II:
• as from EDC 7 C32 software version 30
Description:
The rev-up test allows a check of the cylinders with regard to their even function. For this purpose, cylinders
are switched off consecutively and the engine is then accelerated from idling speed. In the process, the time
required for acceleration is measured. A major deviation for the deactivated cylinder indicates faulty injection
or a defective cylinder.
There are faults that only have an effect when Rail pressures are higher. To increase the clarity of the rev-up
test you can select different Rail pressures for the rev-up test using MAN-cats II with control units as from
software version EDC 7 C32 V35.
Injectors that are stuck (e.g. (as a result of poor quality fuel or FAME fuels) can now be detected with the
rev-up test:
• At low Rail pressure there is a bad test result across all cylinders
• At high Rail pressure there are no abnormalities
The rev-up test for higher Rail pressures is analysed using the same process as for selecting Normal.
Please perform a compression test and evaluate it before performing a rev-up test. Cylinders with a low
compression will also indicate faults during the rev-up test.
Only if the compression test of a cylinder does not result in any abnormality and the rev-up test indicates
a fault, a fault in the injection is highly likely. It can have electrical, mechanical or hydraulic causes.

General conditions for test

• Engine at operating temperature, greater than 75 °C
• Warm up the vehicle by driving; do not let it warm up whilst stationary
• Always run the rev-up test at least twice. It is important that no other consumer such as the
compressor or fan is switched on because it may be switched off during the second test run,
leading to inaccurate results
• After having finished the rev-up test, always switch off the ignition, otherwise the smooth-running
control will not be activated.

3438PEen
Page 109 of 157
Evaluating the rev-up test:
Example for a test result where the engine is OK:

1 2 3

1 = Cylinder switched off, 2 = Engine speed reached after 3 = Engine speed difference
in firing sequence MAN-cats II accelerated of the switched off cylinder
from idling speed regarding the engine speed
acceleration without
switching off an injector
(line 1, centre column)

3438PEen
Page 110 of 157
Example for a test result where cylinder 3 shows abnormalities:
In the present example, the engine reaches almost the same engine speed acceleration as in the first rev-up
test where no injector was switched off although an injector at cylinder 3 is switched off in the second test.
For this reason, cylinder 3 is not working optimally during normal operation.
This does not mean that the injector at this cylinder is faulty, however!
This only means that the respective cylinder has a lower power output. This means that the engine
mechanics must be checked as well: valve clearance, compression, etc.
The rev-up test should thus only be evaluated in conjunction with the compression test. The rev-up test only
compares the cylinders with each other. The test result must also fit the fuel correction quantities in the
Cylinders Monitoring window.

Cylinder 3 is outside the permissible

deviation with its value.

Average value in the present example: 163 Do not include this value
to create an average
Calculating the permissible deviation using value because it is
figures based on experience: already too far off the
• Calculation of an average value of all cylinders that other values.
are approximately at the same engine speed level
• A deviation of ± 25 rpm from this average is still OK.
In the above example, cylinder 3 is outside the
permissible deviation with a value of (163 - 74 =) 89

Note:
• The rev-up test only provides usable results if the previously performed compression test was OK!
• The rev-up test only compares the cylinders with each other.
• The test result must also fit the fuel correction quantities in the Cylinders Monitoring window.
Please see next page

3438PEen
Page 111 of 157
 During the rev-up test cylinder 3 was identified to
have values outside the permissible deviation.
As a result, cylinder 3 therefore demonstrates a
large positive fuel correction volume.
This is intended to compensate for reduced power
output of the cylinder.

3438PEen
Page 112 of 157
6.2.2.4 Cylinder cutoff test
Available in MAN-cats II:
• as from EDC 7 C32 software version 30
Description:
The cylinder cutoff test offers Service the possibility to exclude a certain cylinder from injection while the
engine is idling, i.e. no fuel is injected into this cylinder.
This makes acoustic diagnosis possible, e.g. to identify a faulty cylinder. This becomes necessary if an
electrical fault cannot be detected but the engine is not producing the expected power output, e.g. as a
consequence of mechanical or hydraulic faults.

General conditions for test

• Engine at operating temperature, greater than 75 °C
• Warm up the vehicle by driving; do not let it warm up whilst stationary
• Parking brake applied
• Gearbox in neutral
• Start engine and pay make sure idling speed is at least 600 rpm

3438PEen
Page 113 of 157
6.2.2.5 High-pressure test
Available in MAN-cats II:
• as from EDC 7 C32 software version 34.1
Description:
The high-pressure test is intended for fast detection of faults caused by leaks (e.g. also for error messages
03775, 03776, 03777, 03778, 03779, 03780, 03781) and indicates whether the fault is on the pressure
supply side (high-pressure pump or proportional valve) or on the consumer side (injector, pressure pipe
socket, pressure-limiting valve).

General conditions for test

• Sensors for engine speed, coolant temperature and Rail pressure are OK.
• Engine at operating temperature, greater than 75 °C
• Warm up the vehicle by driving; do not let it warm up whilst stationary
• Parking brake applied
• Gearbox in neutral
• Start engine and pay make sure idling speed is at least 600 rpm

Test sequence:
During the test MAN-cats II automatically actuates four engine speed values (800/700/700/700 rpm).
The Rail pressure is increased to system pressure (1600 bar or 1800 bar) and lowered again to 600 bar
for each individual engine speed (800/700/700/700 rpm). During this process, the time for pressure
build-up and pressure reduction is taken and the results are presented in a table.
Note:
The test result is invalid if engine speeds of — 800/1200/1400/1800 rpm — are actuated.
Cause:
There is a high probability that this is a control unit with an older software version 34)

If these engine speed values have been

used during the test, the result is invalid.

3438PEen
Page 114 of 157
Evaluating a high-pressure test (1600 bar system):

Pressure build-up times:

The pressure build-up times are momentarily not evaluated because there are currently (7/2010) no
significant reference values.

Pressure reduction times:

In a perfectly operating Common Rail injection system the pressure reduction times are between 850 ms
and 1600 ms.
Minimum pressure reduction time limit values:
Engine (fitted in vehicle) Minimum limit value
4-cylinder inline engine (D08) 1300 ms
6-cylinder inline engine (D08, D20, D26) 1100 ms
8-cylinder V-type engine (D2868) 850 ms
8-cylinder V-engine (two high-pressure pumps) 1600 ms

Please observe that other limit values apply to 8- and 12-cylinder V-type engines that are not fitted into
vehicles:
Engine (not fitted in vehicle) Minimum limit value
8-cylinder V-engine (two high-pressure pumps) 1600 ms
12-cylinder V-type engine 1100 ms

3438PEen
Page 115 of 157
If the minimum limit value is not reached, the fault (leak) is on the consumer side (injector, pressure
pipe socket, pressure-limiting valve).
If the minimum limit value is not reached by a significant margin, we recommend to perform the
high-pressure test with an open line at the pressure-limiting valve to narrow down the fault cause. The
pressure-limiting valve must not leak during testing! If this is the case, it indicates a fault in the injector.
Apart from the procedures described above, there is another method to check the pressure-limiting valve.
The so-called "Pressure-limiting valve open test".
This test can be performed up to EDC 7 C32 software version 42 using a DLS tester and MAN-cats II,
see Section 6.2.3.5 and as from software version 43 also directly using MAN-cats II, see Section 6.2.2.6.
Our experience shows that it is relatively easy to fix an increased leakage quantity in engines with low
mileage.
Undo all pressure pipe and injector attachments and then retighten them as prescribed. If these steps do
not produce any positive results, you should measure the leakage quantity individually to identify the faulty
injector(s).
Note:
Identifying one or more leaking pressure pipe sockets is heavily dependent on the engine temperature.

Maximum pressure reduction time limit values:

Engine (fitted in vehicle) Maximum limit value
4-cylinder inline engine (D08) 2000 ms
6-cylinder inline engine (D08, D20, D26) 2000 ms
8-cylinder V-type engine (D2868) 2000 ms
If the maximum limit value is exceeded, the fault (leak) is on the supply side (e.g. a faulty proportional
valve or a blocked zero delivery throttle in the high-pressure pump).
Note:
Before removing the high-pressure pump you should definitely perform another high-pressure test with a new
proportional valve. If the pressure reduction times is over 2000 ms again, refit the original proportional valve
and check the return line to the fuel tank (squashed, kinked and/or possibly blocked).
Simple testing method for the return line:
Route the fuel out of the "OUT" connector on the high-pressure pump into a suitable collecting vessel using
a tube. If the high-pressure test values are subsequently within the permitted range, the fault is caused by a
return line to the fuel tank that does not allow sufficient amounts of fuel to pass through.

Note:
If the following error messages are present in the EDC 7 control unit:
• 03775, 03776, 03777, 03778, 03779, 03780, 03781
entered in the fault memory, however, if the pressure reduction times are OK, you must find the fault(s)
on the high-pressure pump and/or on the proportional valve: Check the delivery capacity of the
high-pressure pump.

Further information about troubleshooting can also be found in the section on the hydraulic test step list in
the system description on accumulator injection for the Common Rail injection system with EDC 7 control
unit (see also Section 7.2).

3438PEen
Page 116 of 157
6.2.2.6 Checking the pressure-limiting valve (test) with MAN-cats II
Available in MAN-cats II:
• as from EDC 7 C32 software version 43
In EDC 7 C3 and EDC 7 C32 control units up to software version 42 there is the possibility to check the
pressure-limiting valve using the DLS tester. See also Section 6.2.3.5.
Description:
The so-called pressure-limiting valve open test is intended to check whether the pressure-limiting valve has a
reduced opening pressure, i.e. whether it opens too early. If the pressure-limiting valve opens at a level that
is too low, the pressure-limiting valve open test determines the limit pressure at which the valve just about
remains closed.
The test is structured in two phases: pressure build-up and pressure test.
During the test the Rail pressure is gradually increased to just under the opening pressure of the
pressure-limiting valve.

General conditions for test

• Sensors for engine speed, coolant temperature and Rail pressure are OK.
• Parking brake applied
• Gearbox in neutral
• Engine running at idling speed

Procedure:
Perform this test initially with connected leakage line of the pressure-limiting valve and subsequently
with an open leakage line of the pressure-limiting valve:
• Perform test with connected leakage line to check whether the pressure-limiting valve opens.
• Subsequently perform the test with opened leakage line to check whether there is a leak at the
pressure-limiting valve. For this purpose, the line on the T piece must be opened and a container
(e.g. from the test case for Common Rail engines) must be placed under the line.
• If there is no fuel in the container after the test, there is no leak between Rail and
pressure-limiting valve.
• If there is fuel in the container after the test, there is a leak between Rail and pressure-limiting
valve. In this case, empty the container first, retighten pressure-limiting valve to 100 Nm and
subsequently repeat the pressure-limiting valve open test with open leakage line.
• If, after retightening the pressure-limiting valve, there is no fuel in the container after
retightening and subsequent repeating of the test, there is no leak between Rail and
pressure-limiting valve.
• If, after retightening the pressure-limiting valve, and a subsequent repeating the test there is
fuel in the container, the rail must be replaced.
⇒ Select the following menu items in the main menu of MAN-cats II to call up the pressure-limiting valve
open test menu item:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Pressure-limiting valve open test

3438PEen
Page 117 of 157
Example for a test result:
After completing the test, the last pressure value at which the pressure-limiting valve was closed and the
state of the valve are displayed.

MAN-cats II can display the following status messages for the pressure-limiting valve:
MAN-Cats display Status of the pressure-limiting valve Procedure
No fault Pressure-limiting valve OK. ----
Pressure-limiting valve Pressure-limiting valve has burst open. Replace pressure-limiting
open valve.
Leakage Pressure-limiting valve leaking, but not burst Replace rail
open.

If the pressure-limiting valve is OK:

⇒ Perform Injector test with DLS tester.

If the pressure-limiting valve has burst open:

⇒ Replace the pressure-limiting valve.

If the pressure-limiting valve is leaking despite having been retightened to 100 Nm:
⇒ Replace the rail.

3438PEen
Page 118 of 157
6.2.3 Measuring the leakage quantity, pressure-limiting valve open test using DLS tester and
MAN-cats II
Available in MAN-cats II:
• As from EDC 7 C3

Description:
DLS = Detektion von Leckage über Spulenwiderstandsmessung (detection of leaks using coil resistance
measurement)

Searching for leaks in the Common Rail injection system is usually difficult because basically every
component (e.g. high-pressure pump, Rail pressure sensor, pressure-limiting valve, injector, pressure
pipe socket) can cause a fault in the high-pressure system.
Additionally, detecting leaks is time-consuming and possible only with special tools and a very good system
knowledge.
Two tests can be performed using the DLS tester:
• Test for leaks at the injectors
• Pressure-limiting valve open test, test for leaks on the pressure-limiting valve

Performing tests using the DLS tester also offers the following advantages:
• no risk of dirt ingress in the Common Rail injection system because it is not necessary to open the
high-pressure system
• Long-winded and time-consuming individual checks for leaks are not necessary. The time
necessary to test for leaks individually can be significantly reduced when using the DLS tester,
depending on the engine and the installation situation in the vehicle.
• The pressure-limiting valve can be tested without going on a test drive or a possible reduction of the
service life (occurred during previous procedures).
• The test result can be documented in MAN-cats II to use it to explain the repair to the customer or
add it to the damaged part as documentation.
The DLS tester can be used in all of today's MAN Common Rail injection systems (EDC 7 C3 and EDC 7
C32). Successor systems have already been taken into account.
For MAN part numbers for the DLS tester, see Section 7.5.1.

3438PEen
Page 119 of 157
6.2.3.1 Measuring principle to test for leaks
The measuring principle is based on the fact that a leak in the high-pressure section of the Common Rail
injection system leads to increased fuel temperature. The hot fuel internally heats up the injector and
therefore the magnetic coil of the injector. This temperature increase can then be measured via the
change in the magnetic coil resistance:

1 Injector with high-pressure leak

2 The hot fuel internally heats up the injector and also the magnetic coil contained in it.
3 This temperature increase of the magnetic coil can then be measured via the change in the
magnetic coil resistance:

A temperature increase of approx. 0.8 °C corresponds to a change in resistance of approx. 1 mΩ. As from a
temperature increase in excess of 4 °C (internal resistance increase in excess of 5 mΩ) the injector can be
classified as faulty.

3438PEen
Page 120 of 157
6.2.3.2 Test setup
The DLS tester is an additional device for MAN-cats II and is fitted between the EDC 7 control unit and the
engine cable harness.
Schematic diagram:

1 2

11

3 4

6 7

8 9

10 10

1 MAN-cats II 8 Signal, Rail pressure sensor, original

2 DLS tester 9 Signal, Rail pressure sensor, manipulated
3 Vehicle/engine cable harness 10 Communication line
4 EDC control unit 11 Plug connection for a second Rail pressure
5 Adapter cable for DLS tester sensor (e.g. V8 engine)
6 Diagnostics socket X200 ST1 Plug connection, injectors
7 Measuring lines, injectors ST2 Plug connection engine periphery
ST3 Plug connection vehicle connection

3438PEen
Page 121 of 157
6.2.3.3 Connection of the DLS tester
Example for connection in trucks, TGS

1 DLS tester 2 DLS tester cable harness with plug connections

The connection to MAN-cats II is established to connect to EDC 7 control unit and engine
using a communication line. cable harness.

Connecting the DLS tester to V-type engines

In engines with two control units (master/slave), two high-pressure pumps and two separate rails
(high-pressure accumulators) each control unit is tested separately using the DLS tester. See following
functional diagrams.
Functional diagram for V12 (D2862, D2842), V10 (D2840) or V8 (D2848) engines

Flywheel

• Two high pressure pumps (HDP) and two proportional valves (ZME)
• Two Rail pressure sensors
• Two separate Rail pressure control circuits
• Each of the control units — master or slave —supplies one cylinder bank.

3438PEen
Page 122 of 157
Special features of the D2868LFxx (V8) engine
The special feature of the D2868LF (V8) engine is that this engine is equipped with only one high pressure
pump (HDP), one proportional valve (ZME), two Rail pressure sensors and two interconnected rails
(high-pressure accumulators).
It is required to manipulate the second Rail pressure sensor to also be able to perform the leakage test in
this system structure.
For this purpose, an additional adapter cable (80.99641-0025) has been included in the DLS tester.
The Rail pressure sensor connections are easily accessible because the engine cover has already been
removed to connect the DLS tester to the control units.
Procedure:
• Connect DLS tester to master control unit and connect the additional adapter cable to the Rail
pressure sensor of the slave control unit.
• Start the engine and set an engine speed of between 800 rpm and 950 rpm.
• Select the master control unit and start it by selecting "Injector test" in MAN-cats II.
• After having completed measurement, switch off the engine and connect only the cable harness for
the injectors from the master control unit to the slave control unit.
• Reconnect the cable harness for the injectors to the master control unit. All other connections such
as engine periphery and vehicle connection remain connected to the master control unit. The
additional cable harness remains connected to the Rail pressure sensor of the slave control unit.
• Start the engine and set an engine speed of between 800 rpm and 950 rpm.
• Select the slave control unit and start it by selecting "Injector test" in MAN-cats II.

Functional diagram V8 truck (D2868LF)

Flywheel

• Only one high pressure pump (HDP) and one proportional valve (ZME), hence only one Rail
pressure control circuit
• Two Rail pressure sensors
• During the test procedure, the disconnected control unit must be set to the manipulated Rail
pressure.

3438PEen
Page 123 of 157
6.2.3.4 Measuring the leakage quantity using the DLS tester
Description:
The measurement is intended to clearly identify faulty injectors without having to remove them or individually
measure the leakage quantity.
Note:
Measuring the leakage quantity only makes sense if the total leakage quantity is too high. For this reason,
always measure the total leakage quantity before measuring the leakage quantity using the DLS tester.
If the vehicle due for testing enables a high pressure test (see section 6.2.2.5), it is not required to measure
the total leakage quantity. Evaluating the high pressure tests may determine whether the problem is on the
supply or consumer side.
An important influencing factor in this measuring procedure is the engine temperature. Changes to
the engine temperature (coolant) during the test effect the measured result because measurement takes
approximately 8 minutes.
To ensure a faultless evaluation of the measured result, the maximum coolant temperature
fluctuation may be 2 °C. For this reason, the coolant temperature at the start and after concluding the
measurement are recorded in the result log.

Procedure for measurement with DLS tester

⇒ Constant coolant temperature of more than 50 °C (the required temperature to be maintained
depends on the ambient temperature)
⇒ Connect DLS tester
(Please observe different procedure with D2868LF — see previous section "Special feature of
D2868LFxx engine")
⇒ Prevent activation of engine fan during measurement
Depending on the vehicle (truck, bus/coach) it is possible to disconnect certain plug connections
such as the plug connection to the Visco fan or the plug connection at the proportional valve of the
hydro motor (hydrostatic fan drive) during testing.
⇒ Engine running at idling speed
An invalid measured result may be caused by engine speed fluctuations (engine "hunting") during
measurement.
Remedy: Increase the idling speed during the measurement to approx. 800 rpm to under 1000 rpm
and subsequently repeat measurement
⇒ Select and start the injector test in MAN-cats II
MAN-cats II main menu Î Workshop routines Î DLS tester Î Injector test
At the start of the measurement, MAN-cats II reads out the engine type and the current Rail pressure
in the EDC control unit. MAN-cats II subsequently sends the start command for the leakage quantity
measurement to the DLS tester depending on the previously read out engine and injection system
information.
In the first step, the DLS tester then carries out resistance measurement on the injector coils at
current Rail pressure. In the next step, the Rail pressure signal is manipulated and the engine
therefore runs with a Rail pressure increased by approx. 400 bar. The resistance at the injector
coils is measured a second time in this phase.
After having concluded measurement, the determined values are transferred from the DLS tester to
MAN-cats II for evaluation. The Rail pressure manipulation is then revoked.
⇒ The measured result is displayed in MAN-cats II

3438PEen
Page 124 of 157
Evaluation of the measured result
Example for a measured result where injectors are OK:
Injectors shown in the example below can be considered to be OK because the resistance changes are
significantly below the defined limit value of 6 mΩ. The currently valid limit values are always displayed in
MAN-cats II.

1 Evaluated cylinder or injector, in firing order 3 Measured coolant temperature.

2 Relative resistance change of the injector Permitted maximum change 2 °C
4 Increased Rail pressure after manipulating
the Rail pressure signal by the DLS tester

3438PEen
Page 125 of 157
Example for a measured result where the injectors show deviations:
In the following example two injectors are causing problems.
The injector for cylinder 3 can be classified as faulty because the resistance change is considerably above
the permitted limit value. The injector for cylinder 6 can be classified as borderline because the value is close
to the limit value.
Limit value of the permissive resistance measurement: 6 mΩ (status 7/2010).
The currently valid limit values are always displayed in MAN-cats II.

Injector for cylinder 3 Injector for cylinder 6

is faulty is borderline

With this measuring procedure, a leak between injector and pressure pipe socket does not cause any
or no significant change in temperature and/or resistance compared to a leak inside the injector.
For this reason, the DLS tester can clearly determine whether the injectors are increasingly leaking.
Leaking pressure pipe sockets can be identified by inverting the process: The pressure-limiting valve
is not leaking and neither are the injectors. So the leak can only be at the pressure pipe socket.

3438PEen
Page 126 of 157
Information on possible incorrect measurements:
Incorrect measurements due to engine speed fluctuations:
An invalid measured result may be caused by engine speed fluctuations (engine "hunting") during
measurement.
Reason: Increasing the Rail pressure during measurement may cause the engine speed control to no longer
be able to maintain the idling speed of, e.g. 600 rpm and the engine "hunts". This engine speed fluctuation
causes very different amounts of fuel to be injected at cylinders 1, 2 and 3 and a useful resistance
measurement is not possible.
Remedy: Increase the idling speed during the measurement to approx. 800 rpm to under 1000 rpm and
subsequently repeat measurement

In the following example, implausible values are displayed for cylinders 1, 2 and 3.

3438PEen
Page 127 of 157
Incorrect measurement due to changes of the coolant temperature:
Coolant temperature changes influence the measured result. The measured result in the following example
cannot be used because the coolant temperature increased by 4 °C during measurement. The maximum
permitted increase would be by 2 °C.
The temperature increase during measurement also caused an increased resistance in the majority of
injectors. Reliable measurement is therefore not really possible.

Example for the influence of a temperature change on the measured result

Measured result:
Temperature °C Injector
Cylinder(s) Leakage
Measurement Leakage ZME Start/finish Replacement
1 2 3 4 5 6
1 100 ml 5,92 % 0 5 0 0 1 1 65/65 2 50 ml
2 50 ml 1,74 % 2 2 1 3 3 2 58/60
3 50 ml 1,74 % -2 -2 -1 -2 -1 -1 60/58
• In measurement 1, all cylinders show the actual change in resistance of the injectors due to the
constant coolant temperature (65 °C/65 °C) during measurement. The defective injector at cylinder 2
was therefore replaced and the measurement repeated.
• In measurement 2 the coolant temperature changed from 58 °C to 60 °C. This temperature rise
increased all injector values even though only the injector of the second cylinder was replaced.
• In measurement 3 the coolant temperature changed from 60 °C to 58 °C. This temperature rise
decreased all injector values even though only the injector of the second cylinder was replaced.

Incorrect measurements due to too many measurements in succession:

Whenever five or more measurements are carried out within a few minutes, the same effect as with a
changing coolant temperature occurs.
All injectors are heated up relatively strongly by the increased Rail pressure and the differences between the
injectors diminish continuously. A reliable evaluation is therefore impeded.
For this reason, allow the engine to cool down at idling speed after two (three at maximum) measurements.

3438PEen
Page 128 of 157
6.2.3.5 Testing the pressure-limiting valve (pressure-limiting valve open test) using the DLS tester
Description:
The so-called Pressure-limiting valve open test is intended to check whether the pressure-limiting valve
(DBV) has a reduced opening pressure, i.e. whether it opens too early. If the pressure-limiting valve opens
at a level that is too low, the pressure-limiting valve open test determines the limit pressure at which the
valve just about remains closed.
The test is structured in two phases: pressure build-up and pressure test.
During the test the Rail pressure is gradually increased to just under the opening pressure of the
pressure-limiting valve.
Up to control unit EDC 7 C32 with software version 40, the Pressure-limiting valve open test using the
DLS tester is the only possibility to increase the Rail pressure to just below the opening pressure of the
pressure-limiting valve. As from control unit EDC 7 C32 with software version 44, the Pressure-limiting valve
open test is also available directly in MAN-cats II. See also Section 6.2.2.6.

Procedure for measurement with DLS tester

⇒ Connect DLS tester.
⇒ Engine running at idling speed.
⇒ Select and start the pressure-limiting valve open test in MAN-cats II.
MAN-cats II main menu Î Workshop routines Î DLS tester Î Pressure-limiting vale open test
At the start of the test, MAN-cats II reads out the engine type and the current Rail pressure in the
EDC control unit. MAN-cats II subsequently sends the start command for the pressure-limiting valve
open test including information such as holding periods or detuning factors for a Rail pressure jump,
etc. to the DLS tester.
By manipulating the Rail pressure signal, the DLS tester gradually increases the Rail pressure up to
just under the opening pressure of the pressure-limiting valve. For this reason, the engine runs with
an increased Rail pressure depending on the fuel system pressure applied (1400 bar, 1600 bar or
1800 bar).
The Rail pressure manipulation is subsequently reduced, so is the Rail pressure (approx.
10 seconds) which is measured at the end of the test and finally transferred to MAN-cats II for
evaluation.
⇒ The measured result is displayed in MAN-cats II

3438PEen
Page 129 of 157
Evaluating the pressure-limiting valve open test
Example for a measured result where the pressure-limiting valve is OK:

Note:
This test does not determine with an absolute certainty whether the pressure-limiting valve is really leaking.
This test result only shows that the pressure-limiting valve was not burst open during this test.
If the pressure-limiting valve open test or the measurement of the leakage quantity in the injectors and the
pressure pipe socket are OK, yet the uncertainty remains of whether the pressure-limiting valve is leaking,
you should repeat the pressure-limiting valve open test and visually check the pressure-limiting valve for
leaks or perform leakage quantity measurement.
The advantage of the pressure-limiting valve open test is that you can increase the Rail pressure to just
under the opening pressure of the pressure-limiting valve while the vehicle is at standstill. This avoids
possible premature damage of the pressure-limiting valve during a test.
Further information about fault causes in the high pressure system can also be found in the system
description on accumulator injection for the Common Rail injection system with EDC 7 control unit
(see also Section 7.2).

3438PEen
Page 130 of 157
Information on possible incorrect measurements during Pressure-limiting valve open test:
Incorrect measurements due to engine speed fluctuations:
An invalid measured result may be caused by engine speed fluctuations (engine "hunting") during
measurement.
Reason: Increasing the Rail pressure during measurement may cause the engine speed control to no longer
be able to maintain the idling speed of, e.g. 600 rpm and the engine "hunts".
Remedy: Increase the idling speed during the measurement to approx. Increase to 700 rpm to 800 rpm and
subsequently repeat measurement.

In the following example, an implausible value was measured under Maximum Rail pressure In MAN-cats,
the term "Maximum Rail pressure" is also referred to as Maximal Rail pressure reached.

3438PEen
Page 131 of 157
 6.2.4 Workshop routines within EDC diagnosis
"Workshop routines" are functions provided by MAN-cats II that enable the workshop to bring the control
unit to a defined status after having replaced or repaired components (e.g. oxygen sensor) without having
to perform time-consuming driving cycles for procedures such as withdrawing the torque limiting.

6.2.4.1 Withdrawing torque limiting

Available in MAN-cats II:
• as from EDC 7 C32 software version 32
If, due to emission-relevant faults (OBD, P codes), torque limiting is triggered and the check lamp of the
exhaust gas aftertreatment flashes, it is possible to withdraw the torque limiting using MAN-cats II and
performing the following:
Note:
Withdrawing the torque limiting and deactivating the flashing check lamp is a radical intervention into
the system which is logged with the date and workshop code (identification number, fingerprint).
The information is stored in the EDC and AdBlue control units (if fitted). It can be read out using
MAN-cats II under menu item Control unit identification.

⇒ After having repaired the component, delete the EDC, OBD and — if present — AdBlue fault memories.
⇒ Select the following menu items in the main menu of MAN-cats II:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Reset torque limiting and flashing MIL

3438PEen
Page 132 of 157
⇒ Follow the on-screen instructions.
The system detects automatically within the menu item whether there is a torque limiting set and whether
it is a vehicle with AdBlue.
The torque limiting and flashing check lamp are reset
⇒ After quitting the Reset torque limiting and flashing MIL menu item, switch the ignition off and wait for the
EDC afterrun.
Note:
To reset the torque limiting upon the next "ignition on", it is essential that the EDC afterrun was
completed successfully!
In vehicles with AdBlue and an empty AdBlue tank, another fault is then detected and the check lamp of
the exhaust gas aftertreatment flashes and a torque limiting is set again briefly after switching to "ignition
on".

3438PEen
Page 133 of 157
6.2.4.2 Initialisation of the lambda correction value
If values of approx. 8000 or -8000 are displayed in the Oxygen sensor values In MAN-cats, the term
"oxygen sensor values" is also referred to as “Lambda values” Monitoring window under Oxygen sensor
correction factor (displayed value/1000) In MAN-cats, the term "Oxygen sensor correction factor (displayed
value/1000)" is also referred to as Oxygen sensor correction factor (displayed value/1000) or the oxygen
sensor was replaced, the oxygen sensor must be taught-in (initialised). The same procedure may be
necessary in the event of fault entry 03938 (oxygen sensor cannot be adapted).
For this purpose, you have two possibilities:
• Teach-in (initialise) using MAN-cats II
• Teach-in during test drive

Initialising the correction factor using MAN-cats II:

Available in MAN-cats II:
• as from EDC 7 C32 software version 34.1
To reinitiate the correction factor for the oxygen sensor without a test drive, please perform
the following steps:

⇒ If applicable, switch off engine, switch off ignition and switch on again.
⇒ Select the following menu items in the main menu of MAN-cats II:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Initialisation of the lambda correction factor

⇒ Confirm the request on the information screen with <Yes> to start initialising the correction factor.
The correction factor is set to 1 using MAN-cats II.
3438PEen
Page 134 of 157
⇒ Finally, confirm the information window with <ENTER>
⇒ Switch the ignition off and on.
Switching off the ignition saves the initialised value during the control unit afterrun
After successfully completing initialisation, the setpoint 1000 can be read out in the Lambda values
Monitoring window under Oxygen sensor correction factor (displayed value/1000) In MAN-cats, the term
"Oxygen sensor correction factor (displayed value/1000)" is also referred to as Oxygen sensor correction
factor (displayed value/1000).

Initialising the correction factor during a test drive:

To reinitialise the correction factor for the oxygen sensor in engines with an EDC 7 control unit and software
older than version 34.1, please perform the following steps:

⇒ Go for test drive until the coolant temperature is in excess of 70 °C

⇒ Let the vehicle coast for 15 seconds from a speed of 60 km/h and subsequently accelerate again.
Please make sure to keep to the 15 seconds otherwise these steps must be repeated.
The correction factor is re-established in coasting mode.
⇒ Switch engine off, switch ignition off and subsequently switch the engine on again
⇒ Check the correction factor in the Lambda values Monitoring window under Oxygen sensor correction
factor (displayed value/1000) In MAN-cats, the term "Oxygen sensor correction factor (displayed
value/1000)" is also referred to as Oxygen sensor correction factor (displayed value/1000).
If the value is not between 890 and 1140, repeat these steps.

3438PEen
Page 135 of 157
 6.2.5 Evaluations
A summary is provided under the „Evaluation“ menu item by MAN-cats II. It allows the workshop to evaluate
the vehicle's deployment conditions in detail to incorporate it during fault analysis or to use it to bring any
arising issue across to the customer.
To use the functions/information of the sections described below select the following menu item in the
MAN-cats II main menu:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Evaluation

3438PEen
Page 136 of 157
6.2.5.1 Operating data
This window provides operating data which are saved in the EDC 7 control unit, such as:
• Engine operating hours from EDC, the total operating hours when the engine was on are displayed.
• Number of performed forced regeneration cycles. A forced regeneration is normally started when the
exhaust gas differential pressure exceeds defined values and there is therefore the risk of a blocked
catalytic converter/filter. This might be caused by the deployment profile of the vehicle. An example
for this would be predominant deployment in distribution transport.
• Consumed total fuel since last filter replacement

Note:
Reliable values for the filter currently fitted in the vehicle (CRT filter, PM-Kat or SCR catalytic converter) are
only provided if the values for the filter have been reset after replacement of the filter using MAN-cats II and
the corresponding function. See Section 6.2.5.3.

3438PEen
Page 137 of 157
6.2.5.2 Signal analysis

6.2.5.2.1 Exhaust gas

This evaluation window provides you with information on the time of the defined operating variable on
a percentage basis, such as exhaust gas temperature, particulate filter temperature and exhaust gas
differential pressure in the respective temperature range. This could enable conclusions on exhaust
gas treatment and independent regeneration of the filter system.
Always reset the operating variables after replacing filters or catalytic converters.
The displayed data is saved after the EDC control unit is switched off.

• Exhaust gas temperature In MAN-cats, the term "exhaust gas temperature" is also referred to as
Exhaust gas temperature downstream of filter.
The distribution of the measured exhaust gas temperatures on a percentage basis upstream of the filter
system is displayed in relation to the displayed analysed period.
Exhaust gas Proportion of engine operating Proportion of engine operating
temperature time, at minimum time, ideally
Over 250°C 30% 60% to 80%
Over 300°C 10% 15% to 25%
If — for example — the proportion of exhaust gas temperature over "250 °C" upstream of the filter must
be determined, it is required to add up all stated time periods upstream of the filter in percent.
• Particulate filter temperature
The distribution of the measured particulate filter temperatures (exhaust gas temperatures sensor
downstream of the filter) on a percentage basis is displayed in relation to the displayed analysed
period.

3438PEen
Page 138 of 157
• Exhaust gas differential pressure In MAN-cats, the term “Exhaust gas differential pressure” is
also referred to as Exhaust differential pressure.
The distribution of the measured exhaust gas differential pressure (exhaust gas backpressure) is
displayed in percentage values in relation to the displayed analysed period.
Depending on the method used for exhaust gas aftertreatment, i.e. PM-Kat, SCR catalytic converter
or CRT filter (bus/coach), the measured exhaust gas pressure in relation to ambient pressure (exhaust
gas relative pressure sensor) is measured, depending on the pressure drop determined at two
measuring points (exhaust gas differential pressure sensor).
See also Section 6.2.1.12, Monitoring Exhaust gas aftertreatment.

3438PEen
Page 139 of 157
6.2.5.2.2 Injection volume and Engine speed
This evaluation window provides you with information about the time of operation of defined engine
parameters on a percentage basis in the corresponding engine speed range and the injection volume
requested at this point.
The displayed data is saved after the EDC control unit is switched off.

3438PEen
Page 140 of 157
6.2.5.2.3 Starter motor
This evaluation window provides information about performed starts. The type of engine start,
the temperature range and the period is provided in addition to the performed engine starts.
If, e.g. there are increasingly problems with the starter, the information provided below may contribute to
finding the fault/analysing it.

• Number of starts
The total number of performed starts (normal starts, emergency starts and dummy starts) are displayed
• Normal start
The table shows the distribution of performed normal starts in the corresponding temperature range
and period of time (actuation time of the starter) in percentage values.
• Request emergency start
The distribution of possibly performed emergency starts in the corresponding temperature range is
displayed in percentage values.
Emergency start: engine start with accelerator pedal fully depressed
• Request dummy start
The distribution of possibly performed dummy starts in the corresponding temperature range is
displayed in percentage values.
Dummy start: Starter unable to move into ring gear. The starting procedure is automatically repeated
until a permissible number of start procedures has been exceeded in the event of the engine not
starting.

3438PEen
Page 141 of 157
6.2.5.3 Reset all values after replacing particulate filter In MAN-cats, the term "Reset all values
after replacing particulate filter" is also referred to as Reset all values after exchanging
particulate trap
In the EDC 7 control unit all information specific for operation is displayed and subsequently stored in the
control unit for the purpose of a long-term backup. This information can be called up under the "Evaluation"
menu item.
Apart from information on starts, etc. information (operating data) on the filter system and/or catalytic
converter such as forced regeneration cycles, fuel consumption, exhaust gas temperature, exhaust gas
differential pressure, etc. is also stored.
As this data can be allocated to the filter system and/or the catalytic converter and serve as a basis for its
evaluation/analysis, this data must be reset when replacing the filter system and/or catalytic converter. This
is the only way to guarantee that the correct information (operating data) to evaluate/analyse the newly fitted
filter system and/or catalytic converter is provided.

To reset the data of the filter system and/or catalytic converter, select the following menu items in the
MAN-cats II main menu:
Diagnosis Î Engine/Exhaust gas aftertreatment Î EDC Î Evaluation Î Reset all values after replacing
particulate filter In MAN-cats, the term "Reset all values after replacing particulate filter" is also referred to
as Reset all values after exchanging particulate trap.

3438PEen
Page 142 of 157
6.2.5.4 EDC trend data
The EDC trend data should be read out if, e.g. there are complaints regarding fuel consumption and
performance (SI 301100), work on the exhaust gas aftertreatment system (e.g. replacing a catalytic
converter or filter) is being performed and work in the course of Service Information sheets331810 or
3306AT is required.
By running the EDC trend data menu item, those values (in addition to operating data) that are grouped
together under the Signal analysis menu item as well as additionally various engine characteristics and
engine maps from the EDC control unit are read out and saved on the MAN-cats II service computer.
Upon the next reconnection to the central MAN-cats server, the stored file with the so-called EDC trend data
is automatically transferred to this server and is subsequently available to experts at MAN Nutzfahrzeuge to
be used in conjunction with support requests according to SI 500SM and 1994SM.

3438PEen
Page 143 of 157
7 Literature/tools, etc.

The following documentation and tools offer further information on the topics covered in this SI.

7.1 Repair manuals:

Cable harnesses, seals, special tools ........................................................................... N 01, 1. Edition
Engine repair manuals, see Intranet, Extranet (overview) or MANWIS

7.2 System description

Accumulator injection of Common Rail system EDC 7.................................................. T 18 Edition 5
Heavy duty on-board diagnostics (HD-OBD)................................................................. T 100 Edition 2
CAN data bus................................................................................................................. T 51-A1 Edition 3
MAN AdBlue system...................................................................................................... T 110 Edition 2

7.3 MAN-cats II software:

Service CD........................................................................................................ 10.01.00 81.99585-4000

7.4 Service Information sheets

Rail, injector, EDC 7 control unit, D2876LF12, D2876LF13, D2876LOH20, D2876LOH21
engines: Engine does not run smoothly, development of smoke, performance deficiency, etc.........SI 132400
EDC 7 control unit, TGA with D2876LF12 or D2876LF13 engine......................................................SI 159300
Exhaust gas recirculation, truck and bus/coach: Various problems
with the exhaust gas recirculation (EGR) module ..............................................................................SI 169000
Engine, fuel system, auxiliary heater, all vehicles, operation of
MAN engines/vehicles with FAME "biodiesel")...................................................................................SI 180911
EDC control unit, TGA with D20xx engine: Fault messages EDC 03778, 03779, 03780 ..................SI 182402
EDC control unit, truck and bus/coach: Engine cannot be started after ignition off/on ......................SI 196602
EDC 7 C3 control unit, truck and bus/coach: Control unit cannot be flashed ....................................SI 235702
EDC control unit, D0836LUH50, D0836LOH50 engines: Fault message EDC 03785 ......................SI 225100
EDC control unit, truck and bus/coach with D0834xx or D0836xx engine:
Fault messages EDC 03814, 03785, 03853.......................................................................................SI 241800
EDC control unit, flame start system, D0836xx engine:
White smoke and engine not running smoothly..................................................................................SI 249800
EDC control unit, D0836LF51 engine: Intermediate speed control is not actuated correctly.............SI 251000
Injector cable harness, D20 and D26 engines, oil leak at the injector cable harness ........................SI 266300
EDC control unit, TGA, TGS, TGX with D2066LF23, D2066LF24 or D2676LF12 engines:
Fault message EDC 03811.................................................................................................................SI 273000
EDC control unit, D0836xx engine: Shaking in partial load range at 1400 to 1600 rpm ....................SI 276600
EGR adjusting cylinder, trucks and buses/coaches with EuroIV engine (Euro4)
D0834CR or D0836CR with controlled EGR: Fault messages EDC 03850, 03851, 03853 ..............SI 276700
EDC control unit, oxygen sensor, D0836LF53, D0836LF54, D0836LF55 engines:
Error message EDC 03837.................................................................................................................SI 295400
EDC control unit, OBDD0834LFL53, D0834LFL54, D0834LFL55, D0834LOH52,
D0834LOH53 engines: OBD fault memory entries P2bAE or P2bAD................................................SI 301700
Complaints about consumption and performance, engines with Common Rail.................................SI 301100
EDC 7 C32 control unit, buses/coaches, TGL, TGM, X-types with D0836 engine:
Error messages EDC 03868, 03871, 03872, problems during diagnosis with MAN-cats II ...............SI 310200
EDC control unit, vehicles with EDC 7 C32, control unit with an older software version ...................SI 334700

3438PEen
Page 144 of 157
EDC control unit, D2066LF17, D2066LF18, D2066LF19, D2066LF20,
D2676LF15, D2676LF16, engine conversion from no torque reduction to torque reduction.............SI 340800
EDC control unit, D0836LFL60, D0836LFL63, D0834LOH60, D0834LOH61 engines:
EDC 03929 error message, vehicles move off poorly and/or engine does not idle smoothly............SI 343500
EDC 7 C32 control unit, bus/coach and bus/coach chassis with
D0836LOH60, D0836LOH61, D0836LOH64 or D0836LOH65 engines,
vehicles do not always start without problems in low temperatures...................................................SI 357700

Service contacts, support by central departments .............................................................................500SM

Trend data ..........................................................................................................................................1994SM

Ordering programming data, genuine MAN software,

conversion data file, control unit replacement ....................................................................................3237SM

3438PEen
Page 145 of 157
7.5 Tools
7.5.1 Tools - electrical system
• 88-pin test box with measuring bridges 80.99641-6027

• 100-pin adapter cable set for test box Typesetting: 80.99641-6025

for EDC 7 C3 and EDC 7 C32
consisting of:

80.99641-0030

80.99641-0071

80.99641-0031
80.99641-0034

80.99641-0033
80.99641-0032

Alternative

80.99641-0072

3438PEen
Page 146 of 157
• 62-pin test box with cables for 4, 6 and 7-pin 80.99641-6044
connections
e.g. for trailer control module, EDC sensors
and gearbox sensors, oxygen sensor, etc.

• Measuring bridge for checking and 80.99641-6026

adjusting sensors
(e.g. for EGR adjusting cylinders)

• Fluke ScopeMeter 123/S/124 commercial

08.78023-0000
vehicle package

3438PEen
Page 147 of 157
 • DLS tester 80.99641-6033
for EDC 7 C3 and EDC 7 C32 (complete system)

80.99641-6032

80.99641-0024

80.99641-0025
Additional connection cable for V8 engine

3438PEen
Page 148 of 157
7.5.2 Tools — Common Rail injection system, AdBlue system

• CR engines test kit 80.99607-6050

• Test kit extension for V-type engine test kit 80.99607-6051

• AdBlue test kit 80.99607-6038

3438PEen
Page 149 of 157
 • Refractometer 08.77601-0000

3438PEen
Page 150 of 157
8 Error message/descriptions:
The implemented monitoring and self-diagnosis functions of the electronic injection system should ensure
maximum availability and in case of a fault should assign the error as quickly as possible to a path and
component(s).
The faults are identified in various ways:
• Evaluation of the permissible value range of a signal
• Plausibility check of a signal by means of other signals
• Checking that a signal is provided on time
• Plausibility check of a subsystem by comparing the target state with the current state
In case of a fault, the error messages can be read out using MAN-cats II or displayed automatically/on
request on the instruments.
Error messages can be looked up in the EDC 7 system description and in MAN-cats II on the information
portal in the SPN search engine and/or within the EDC 7 system description under SPN help.

3438PEen
Page 151 of 157
9 Circuit diagrams:

Overview of additional circuit diagrams

9.1 EDC 7 C3 and EDC 7 C32 (version: 07/2010)

Vehicles Circuit diagrams Comments

81.99192-1648 D0834LFL42, without EGR
81.99192-1649 D0836LFL40, D0836LFL41, without EGR
81.99192-1650 D0836 LFL44, without EGR
81.99192-2849 D0834LF40, D0834LF41
81.99192-3071 D0836LFL50, EuroIV
81.99192-3072 D0834LFL50, EuroIV
81.99192-3094 D0836LFL52, EuroIV
81.99192-3153 D0834LFL53, D0834LFL54, D0834LFL55, EuroIV

TGL, TGM 81.99192-3154 D0836LFL53, D0836LFL54 EuroIV

81.99192-3155 D0836LFL55, EuroIV
81.99192-3168 D0834LFL60, D0834LFL61, D0834LFL62, EuroV, EEV
81.99192-3169 D0836LFL60, EuroV, EEV
81.99192-3176 D0836LFL61, D0836LFL62, EuroV, EEV
D0834LFL63, D0836LFL64, D0836LFL65,
81.99192-3696
EuroV with DOC catalytic converter
81.99192-3697 D0836LFL63, EuroV with DOC catalytic converter
D0836LFL64, D0836LFL65, EuroV with DOC
81.99192-3698
catalytic converter
81.99192-2834 D2876LF
81.99192-2864 D2066LF
81.99192-2923 D0836LF43
81.99192-3047 D2066LF, EuroIV, PM-Kat
81.99192-3075 D2676LF, EuroIII, with EGR
TGA
81.99192-3081 D2676LF, EuroII
81.99192-3156 D2066, D2676LF, EuroV
81.99192-3161 D2066, D2676LF, EuroIV
81.99192-3447 D2066LF, EuroV, with AdBlue
82.99192-8742 D2840LF25 (H94, H95, 95X)
TGS, TGX 81.99192-3103 EuroIV with PM-Kat
81.99192-3157 D2066, D2676LF, EuroV
81.99192-3162 D2066, D2676LF, EuroIV with EGR
81.99192-3234 EuroV, with AdBlue
81.99192-3760 TGS-WW, EuroII, D2676LF
82.99192-1233 D2868, V31
81.99192-3554 D2066, D2676LF, EuroV with EGR
81.99192-3624 D2066LF, EuroIII

3438PEen
Page 152 of 157
 Vehicles Circuit diagrams Comments
81.99192-3625 D2676LF, EuroIII
81.99192-3693 D2868, V31
81.99192-3760 D2676LF, EuroII
82.99192-8911 D2868
81.99192-1642 D2066LF, EuroIV with PM-Kat
81.99192-2794 D0836LF41 (X60, X61, X92, X93), EuroIV
X-types
82.99192-1290 D2868, large fire-fighting tank truck
81.99192-3008 D2842 LF10, (X36)
81.99289-5833 D0836LUH40, 41
D2066LOH, D2676LOH with EuroV,
81.99289-5896
EEV and low-temperature concept
81.99289-5955 D0836LOH40, D0836LOH41 (A37, A38) Cradle
81.99289-5970 D0836LUH40, D0836LUH41 (A20, A21, A22, 466, 486)
81.99289-6006 D2066LOH20, 21
81.99289-6037 D2066LUH01 up to LUH04
81.99289-6059 D2066LOH with PM-Kat
Buses/coaches, 81.99289-6106 D0836LOH5x EuroIV, EuroV, EEV, hybrid
bus/coach chassis
81.99289-6110 D2066LUH01 to 04 with PM-Kat
81.99289-6147 D2066LF03, D2066LF04, FOC — RSA
81.99289-6162 D2066LUH EEV (A2x)
D2066LOH, D2676LOH,
81.99289-6240
EuroV with low-temperature concept
PM-Kat with D08xxLOH, D2066LUH, D2066LOH,
81.99289-6250
D2676LOH EuroIV and OBD1B;
81.99289-6279 D2066LUH EEV
81.99289-6250 PM-Kat with D2066LUH EuroV

If you have no Intranet/Extranet or MAN-cats II access to view the required circuit diagrams, please contact
the After Sales department (see current version of 500SM).

3438PEen
Page 153 of 157
Note:
If there is any uncertainty as to whether the circuit diagram numbers listed here are for your vehicle or the
one for your vehicle is missing and you require it for fault diagnosis, you can find out the number using
MAN-cats II.
This is currently only available for vehicles with Trucknology technology. Only circuit diagrams are listed
here that comply with the ex-works state of the vehicle.

You can determine circuit diagrams as follows:

⇒ MAN-cats II main menuÎ Vehicle programming Î Information Î Information about vehicle

from vehicle and conversion data file Î Vehicle data file Î From vehicle's vehicle management
computer
After the vehicle data file has been read out you are given a menu with various groups of
information.

⇒ Select the Information, system circuit diagrams menu item In MAN-cats, the term
"Information, system circuit diagrams" is also referred to as Information, system
diagrams.and confirm with < ENTER >. You are subsequently given an overview of the
circuit diagrams for your vehicle.
Only those circuit diagrams will be shown that were used when producing the vehicle.
Retrofitted scopes will not be included or displayed.

3438PEen
Page 154 of 157
Example screen

3438PEen
Page 155 of 157
9.2 Overview, EDC 7 fuel diagrams (version: 07/2010)
9.2.1 D2868LF02/LF03 (V8) engine fuel diagram — up to approx. October 2007
Key:
5
7 1 Fuel tank
2 D2868LF03 only
3 SEPAR filter
20 4
4 Hand primer pump
5 Supply pump
6
6 Control units
8
3 7 Fuel Service Center (KSC)
10 8 Fuel pressure sensor
9 9 Crankcase
10 KSC drain valve
12
11 Flame start solenoid valve
11
12 Flame glow plugs
13 2
13 High-pressure pump
14 Proportional valve (ZME)
17 15 High-pressure accumulator (rail),
right
14
16 High-pressure accumulator (rail),
1 left
15 17 Injectors
17 18 Rail pressure sensors
19 Pressure-limiting valve
16 19 20 Fuel filter heating (2x)
B A Engine
B Vehicle frame
A

3438PEen
Page 156 of 157
9.2.2 D2868LF02/LF03 (V8) engine fuel diagram — as from approx. October 2007
Key:
8
9 1 Fuel tank
2 D2868LF03 only
3 Return line, high-pressure pump
22 7
4 KSC return line
10 5 Connection between KSC
and high-pressure pump,
D2868LF02 only
6
12 6 SEPAR filter
11 7 Hand primer pump
8 Supply pump
14 5 9 Fuel Service Center (KSC)
13
4 2 10 Fuel pressure sensor
15 11 Crankcase
12 KSC drain valve
13 Flame start solenoid valve
19
3 14 Flame glow plugs
16 15 High-pressure pump
1 16 Proportional valve (ZME)
17 17 High-pressure accumulator (rail),
right
20
18 High-pressure accumulator (rail),
left
18 21
B 19 Injectors
20 Rail pressure sensors
21 Pressure-limiting valve
A
22 Fuel filter heating (1x)
A Engine
B Vehicle frame

3438PEen
Page 157 of 157