Powersystems • Industrial Engines

Electronical Engine Control

Series 457, 500 and 900

Advanced Training

As at 04/03

Powersystems • Industrial Engines

Electronical Engine Control Series 457,
500 d 900 Ad dT i i
This document is provided for training purposes only and is not subject to the normal updates.

Printed in Germany Note:

ã 2003 Copyright DaimlerChrysler AG The term "employee" always refers to both male
and female staff.
Issued by: Global Training
This documentation and all its constituent parts are subject to copyright. Any reproduction or re-use requires written
permission from DaimlerChrysler AG in advance. This especially applies to any form of duplication, dissemination,
editing, translating, microfilming, or storage and/or processing of this documentation on electronic systems,
databases or online services.

st
1511 1210 02 - 1 edition 04.03 72 As at 04/03
 Contant 07.05.2003

Title Side

Welcome ..................................................................................................................................................................................................................................................1
Course targets .........................................................................................................................................................................................................................................2
Structure and principle of operation of the engine control (MR).............................................................................................................................................................3
MR/PLD engine control ...........................................................................................................................................................................................................................4
MR components - BR 500 ........................................................................................................................................................................................................................8
MR components - BR 900 ......................................................................................................................................................................................................................10
Telligent engine control..........................................................................................................................................................................................................................12
Rotational speed, crank angle and TDC detection.................................................................................................................................................................................17
Evaluation of crankshaft and camshaft angles ......................................................................................................................................................................................19
Temperature detection ..........................................................................................................................................................................................................................20
Oil pressure sensor, oil temperature sensor .........................................................................................................................................................................................22
Oil level detection ..................................................................................................................................................................................................................................23
MR control loop......................................................................................................................................................................................................................................24
Engine control parameterization............................................................................................................................................................................................................25
Starter actuation through the MR..........................................................................................................................................................................................................26
Direct starter actuation..........................................................................................................................................................................................................................28
Telligent engine system .........................................................................................................................................................................................................................30
ADM - FR ................................................................................................................................................................................................................................................32

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Contant I 1
ADM - 2 ..................................................................................................................................................................................................................................................34
ADM - AR and FR....................................................................................................................................................................................................................................36
Pedal communication functions of the Mercedes-Benz foot throttle actuator......................................................................................................................................40
Alternators .............................................................................................................................................................................................................................................42
Engine brakes ........................................................................................................................................................................................................................................48
Turbobrake.............................................................................................................................................................................................................................................50
Flame starting system............................................................................................................................................................................................................................60
Heater flange in Mercedes-Benz engines ..............................................................................................................................................................................................62

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Contant I 2
 Welcome 07.05.2003

MR engine control module GT07_15_0001_00

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Welcome 1
 Course targets 07.05.2003

After working through this document, you will be able to:

· Explain the basic procedure for diagnosis of the engine control (MR).
· Name and locate the components required by the MR.
· Describe the relation between engine speed, crankshaft angle and TDC detection.
· Describe the engine control loop.
· Name the most important MR parameters.
· Explain the functional principle of direct starter actuation and starter actuation through the MR.
· Explain the basic structure and operation of the Telligent electronic engine control.
· Explain the basic structure and operation of the FR adaptation module (ADM), and ADM 2.
· Explain the basic principle of operation of the pedal transfer functions of the Mercedes-Benz foot throttle actuator.
· Explain the basic structure and operation of the compact alternators installed in industrial engines.
· Explain the basic structure and operation of the engine brake systems used, in particular the Turbobrake.
· Explain the basic structure and operation of the flame starting system and heater flange on Mercedes-Benz industrial engines.

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Course targets 2
 Structure and principle of operation of the engine control (MR) 07.05.2003

Short description of the MR engine control module

The "MR" engine control module controls the electronic diesel injection system and is intended for engines of the 457, 500 and 900 model series, among others.
The main function of the control module is the precise, electrical actuation of the solenoid valves at the unit pumps. To do this, the optimal start of injection and
the injected quantity needed for the required torque (or specified rpm in working speed control mode) is calculated and set by the on-board control module,
using the performance map and according to the detected engine and ambient conditions.
The control module also provides fault detection, emergency mode functions, and diagnoses.

Protection/redundancy:

The PLD/MR is configured as a 2-computer system, which means that if the host CPU fails, the back-up computer takes over the control of the solenoid valves at
the unit pumps. In this case, the engine speed remains constant (about 1300 rpm). The redundant operation (i.e. if one functional component fails, at least one
other functional component is available to take its place) applies also to solenoid valves (unit pumps), rpm sensors, starter actuation and the engine CAN bus
(single-wire mode capability). The electronic system also has a watchdog circuit, extensive self-tests are performed continuously, and mutual monitoring is
performed with the ADM electronics.

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Structure and principle of operation of the engine control (MR) 3
 MR/PLD engine control 07.05.2003

The MR (PLD) engine control system receives guideline values from the drive
control (FR) or ADM in the form of 'desired torque' factors.

Using these values, the fuel delivery and start of injection at the unit pumps is
controlled in relation to a series of performance maps and characteristics
stored in the control module, and the actual operating conditions of the
engine.

BR 500
A3 FR control module or ADM control module
A4 Flame starting system control module
A6 MR Control module
B9 Charge air temperature sensor
B10 Fuel temperature sensor
B11 Oil temperature sensor
B13 Boost pressure sensor
B12 Oil pressure sensor
B14 Oil level sensor
B15 Crankshaft angle position sensor
B16 TDC sensor cylinder 1
B65 Coolant temperature sensor
M1 Starter
S10 Engine start pushbutton switch
S11 Engine stop pushbutton switch

N15.00-2067-12

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MR/PLD engine control 4
BR 900

A3 FR control module or ADM control module

A4 Flame starting system control module
A6 MR Control module
B10 Fuel temperature sensor
B14 Oil level sensor
B15 Crankshaft angle position sensor
B16 TDC sensor cylinder 1
B65 Coolant temperature sensor
B110 Combination oil temperature / oil pressure sensor
B111 Combination charge air pressure / temperature sensor
Y2 Constant throttle solenoid valve, 6-cyl.
Y6-Y11 Unit pump solenoid valves, cylinders 1 - 6
S10 Engine start pushbutton switch
S11 Engine stop pushbutton switch

N01.00-2124-06

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MR/PLD engine control 5
Task m Now assign the components to the correct functions. Not all components are linked into the
conventional engine management system! In the "Engine management" column, identify the
components required for engine running.

Component Has the following function: Engine

management
Unit pump (Y...) Builds up pressure and deliver fuel as required.

Detects coolant temperature.

Detects fuel temperature.

Detects charge air temperature.

Detects oil temperature.

Determines oil pressure in the oil circuit.

Boost pressure sensor (B13) Determines boost pressure in the intake pipe.

Determines oil level in the oil pan.

Determines the position of the crank mechanism.

Determines the camshaft position and communicate the TDC

point.
Controls start of start of delivery and length of delivery.

atmospheric air pressure sensor* Detects atmospheric pressure.

* Installed in the MR control module.

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MR/PLD engine control 6
MR engine control components, BR 457

W07.15-1117-06 W07.15-1116-06

A6 MR/PLD control module with fuel cooler Fuel temperature sensor

Crankshaft position sensor Coolant temperature sensor
Cylinder 1 TDC sensor at camshaft Combination oil sensor (temperature, pressure)
Combination charge air sensor (temperature, pressure)

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MR/PLD engine control 7
 MR components - BR 500 07.05.2003

W07.15-0005-09

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MR components - BR 500 8
 W07.15-0006-09

MR control module (A6) Crankshaft angle position sensor (B15) Oil temperature sensor (B14)
TDC sensor, cylinder 1 (B16) Oil level sensor (B14) Charge air temperature sensor (B9)
Oil pressure sensor (B12) Starter (M1) Engine stop pushbutton switch (S11)
Engine start pushbutton switch (S10) Coolant temperature sensor (B65) Boost pressure sensor (B13)
Unit pumps (Y6-Y...) Starter relay Fuel temperature sensor (B10)

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MR components - BR 500 9
 MR components - BR 900 07.05.2003

W07.15-1019-09

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MR components - BR 900 10
 W07.15-1020-09

MR control module (A6) Crankshaft angle position sensor (B15) Combination oil pressure/temperature
TDC sensor, cylinder 1 (B16) Oil level sensor (B14) sensor (B110)
Engine start pushbutton switch (S10) Starter (M1) Combination charge air pressure /
Fuel temperature sensor (B10) Coolant temperature sensor (B65) Charge air temperature sensor (B111)
Starter relay Engine stop pushbutton switch (S11)

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MR components - BR 900 11
 Telligent engine control 07.05.2003

Location of the unit pump in the case of the BR 500 engine

The injection process is performed by the newly

developed pump-line-nozzle (PLD) system,
controlled by the Telligentâelectronic engine
management system.

In the PLD system, fuel is delivered to the

injection nozzle by individual unit pumps through
short, relatively rigid high-pressure injection lines,
and through the pressure pipe connection
screwed into the cylinder head.

A unit pump fitted to the crankcase is assigned to

each cylinder. The pump is driven by another
timing cam on the camshaft. Therefore, the
camshaft also has the task of driving the unit
pumps, besides the traditional function of driving
the intake and exhaust valves.

The operating principle of the unit pump is based

on the same principle as the piston pump, as in
the in-line injection pumps used till now, but
without control edges at the pump plunger.

The quantity injected is determined individually

per cylinder by solenoid valves, which control the
start and end of injection.

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Telligent engine control 12
 Sub-Menu Homepage

N07.02-2018-06

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Telligent engine control 13
PLD components

1 Camshaft
2 Roller tappet
3 High-pressure cylinder
4 Injection nozzle
5 Pressure line
6 Valve body
7 Unit pump solenoid
8 Unit pump head
9 High-pressure chamber
10 Pump plunger
11 Pressure pipe
12 Suction gallery

N07.15-2031-06.

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Telligent engine control 14
Unit pump delivery phases

Unit pump operation is divided into 4 delivery phases

.

N07.15-2024-01 N07.15-2025-01

Intake stroke Initial stroke Delivery stroke Residual stroke

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Telligent engine control 15
Unit pump actuation

The beginning of fuel injection (start of injection) must take place at a certain crank position
determined by the rotary sensor and by the control module.

Chronologically, start of delivery comes before the actual start of injection.

Before the actual start of delivery, the control module places a voltage at the unit pump concerned.
This creates a magnetic field in the coil, which causes the anchor plate to be drawn along with the
screwed-on valve body through channel A into the valve seat, where it is held. The time required to
do this is called the response time.
When actuated, the current at first rises to about 16 A, and as the gap (clearance) between the
anchor plate and the magnetic core decreases, the current drops to around 10 A. If the falling
current goes below a set value, this is detected by a detector circuit in the control module and
identified as a reference mark or hit detection.

In this way, the hit detection is set as the bottoming point of the valve body.

The pressure build-up just before start of delivery by the pump plunger causes the injection nozzle
needle to lift, and injection to begin.

The control module sets the end of delivery by breaking the voltage supply to the coil, and this
causes the magnetic field in the unit pump solenoid to collapse.
This allows the return spring to push the valve body out of the valve seat and against the valve stop
in the suction chamber.

N07.15-2026-12

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Telligent engine control 16
 Rotational speed, crank angle and TDC detection 07.05.2003

Principle of the mechanical coupling

The position of both rotary sensors "crank angle position sensor" and "TDC sensor, cylinder 1" (camshaft
angle position sensor) depends on the mechanical engagement of the camshaft and crankshaft
sprockets, which are coupled to each other.

With a gear ratio of two crankshaft rotations to one camshaft rotation, one complete working cycle of all
cylinders gives a crankshaft reference system of 720°.

For signal generation, the following mechanical coupling relative to crankshaft position (° KW) results:

Camshaft BR 500
12 pins for distance of 60° crankshaft
+1 additional pin for 55° KW before TDC
Camshaft BR 457 and BR 900
12 holes for distance of 60° crankshaft
+1 additional hole for 55° crankshaft before TDC
Crankshaft BR 457 and BR 500
36 grooves for distance of 10° crankshaft
+1 additional groove for 65° crankshaft before TDC

Crankshaft BR 900
36 holes for distance of 10° crankshaft
+1 additional hole for 65° crankshaft before TDC

N07.15-2028-73

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Rotational speed, crank angle and TDC detection 17
Rotary sensor

Induction-type pulse generators are used for detecting instantaneous crank angle and rotational speed.
These pulse generators have a coil around a soft iron core with permanent magnets connected to them,
so that the field lines from the magnets penetrate the core.
The end of the soft iron core is set at a minimum distance from the rotating flywheel or camshaft
sprocket. As the 'marks' (grooves, pins, or holes) rotate, a voltage is induced in the coil (in the same way
as the ABS rotary sensor) by the variation of the magnetic flux lines.

Crankshaft angle position sensor

The sensor placed at the flywheel detects the rotational speed and crankshaft angle by
means of 36 symmetrically arranged grooves or holes (1).
From the received signal, the electronics also determine variations in crankshaft rotational
speed between the individual working cycles and regulates cylinder uniform speed at idle.
An additional 37th groove (65° before TDC), depending on the signal synchronization (see
below), sends the trigger point for calculating the start of delivery.

Cylinder 1 TDC sensor (camshaft angle position sensor)

In case of requirement, the sensor placed at the camshaft sprocket sends the rotational
speed by means of 12 symmetrically arranged pins.
An additional 13th pin (13th hole) (55° before TDC) is needed for signal synchronization, as the
trigger point for calculating the start of delivery.

Resistance = 1000 - 1385 W

N07.15-2032-03

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Rotational speed, crank angle and TDC detection 18
 Evaluation of crankshaft and camshaft angles 07.05.2003

At engine start, a matching (synchronization) of the two signals from the crankshaft angle position sensor and cylinder 1 TDC sensor is performed in the
electronics.
If both signals are present, all actions are coupled to the crankshaft. The crankshaft signal has priority.
The camshaft signal is only used to check that both signals match.

Task m The signal function should be easy to understand, but what is the effect if a signal is missing?
Identify the possible effects in the table below, and indicate whether a fault code is displayed.

Double
Signal failure in .... Limited power actuation of unit Engine does not Engine stops Fault code
output / torque pump per start automatically indication
working cycle
Crankshaft angle position sensor at start-up
Crankshaft angle position sensor with engine running
Cylinder 1 TDC sensor at start-up
Cylinder 1 TDC sensor with engine running
Both sensors

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Evaluation of crankshaft and camshaft angles 19
 Temperature detection 07.05.2003

Various temperature values have to be detected in the engine, for optimal control of start of delivery in all engine operating conditions, for the engine protection
system, and for actuation of the electromagnetic fan clutch.

From start of production of the BR457, BR 500, and BR 900, the coolant, fuel, and charge air
temperatures were detected by three temperature sensors. Since then, the fuel temperature sensor has
been removed from the BR 500. Nevertheless, fuel temperature is taken into account along with coolant
temperature for calculating fuel quantity.

The structure and principle of operation on these temperature sensors are the same:

The temperature sensor housing contains a temperature-sensitive resistor (1) with negative temperature
coefficient (NTC thermistor). Since its electrical resistance falls as temperature increases, this component
is referred to as a thermal resistor.

If connected to the battery voltage, these temperature sensors are destroyed by overheating.

W07.15-0022-02

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Temperature detection 20
Coolant and temperature sensor characteristic:

The coolant and temperature sensors are similar in structure. Since temperature detection has to be
sensitive over a wide temperature range (operating temperature from - 40 to + 130 °C), the limit values
are far apart on both sensors.

Resistance values of the charge air temperature sensor:

Operating temperature - 30 to + 130 °C

Resistance values:

- 10 °C 7980 W to 10560 W
+ 20 °C 2280 W to 2750 W
+ 80 °C 290 W to 365 W

W07.15-0023-02

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Temperature detection 21
 Oil pressure sensor, oil temperature sensor 07.05.2003

Oil pressure sensor

In vehicles with MR/PLD engine control, the oil pressure sensor is not
connected directly to the oil pressure gauge on the instrument panel. So that
the instrument panel can indicate oil pressure, values are detected by the MR
control module and sent continuously over the CAN bus to the adaptation
module (ADM).

Oil temperature sensor

At present, the MR control module does not need the oil temperature sensor
for engine control.
The temperature value is detected and placed on the CAN bus.
The engine temperature is also taken into account in calculating oil level.

Representation on the BR 500 W07.15-0029-11

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Oil pressure sensor, oil temperature sensor 22
 Oil level detection 07.05.2003

The MR control module detects the oil level in the engine through the oil level sensor. The detected value
is placed on the CAN bus.

If the value differs from normal level, the ADM sends a warning indication.

W07.15-0030-01

Function:

A sensor probe of about 210 mm in length is screwed into the engine oil pan. The probe is designed so that the measured level is detected from about 100mm.
Level measurement is started on terminal 15 when the ignition is switched on. A constant current pulse then passes through the probe for 1.5 seconds and
heats a hot wire, thus raising the resistance.
At the start of the current pulse, and just before the end, the voltage over the hot wire is measured and the voltage difference compared with a pre-set threshold
value.
If the temperature increase, and consequently the voltage difference, goes over the pre-set threshold value, then the oil level is too low and the warning lamp is
lit on the instrument cluster.
The sensor probe is linked with the MR/PLD control module, and over the CAN data bus with the ADM control module, which controls the indicator lamp on the
instrument cluster.

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Oil level detection 23
 MR control loop 07.05.2003

The basic operation of the engine control can be

represented as a simple control loop.

A control loop consists of the controlled system

(in this case the engine) and the control device (in ADM
this case the control module).

The ADM sends the specified value in the form of

a preset engine value. The controlled system (the
engine) sends the actual value in the form of the
value actually present.
The MR compares the specified value with the
actual value (the conditions actually present).

The actual value thus represents the real

operating conditions in the engine, as detected by
the various sensors.

In the comparison, if the actual value is found to

be higher than the specified value, the injection
control reduces the injection quantity. If it is
found to be lower, the injection control raises the
injection quantity.
Thus, the actual value is continuously compared
with the specified value.

N07.15-2027-75

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MR control loop 24
 Engine control parameterization 07.05.2003

For ordering a new engine control electronic system, the required parameters are found on the model
plate.

Legend:

1 = MB number and data record number

2 = Certification No.
3 = Engine number
4 = Device code

N07.15-2017-20

For ordering a new MR control module, the required data can be read out of the old MR with Minidiag 2.

MR Parameter Value Explanation

01 Engine number XXXXXX-XX-XXXXXXX Actual engine number

02 MB number and data record number A XXX XXX XX XX ZGS XXX The loaded data record with update level
03 Certification number OM XXX XX. XX/X-X Certified engine model
04 Device code 1 XXXX.XXXX.XXXX XXXX.XXXX Power correction code. The EOL data. These can be determined on the bench dynamometer by the end of
production (End of Line).
05 Device code 2 XXXXX Code for the configured MR parameters 06-16

Parameters should only be changed after obtaining the approval of the engine installer!

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Engine control parameterization 25
 Starter actuation through the MR 07.05.2003

Function description

Engine start with the drive switch After the ignition (tml.15) is switched on and the ignition key is turned to the start position (tml. 50), the
FR sends the engine start request over the CAN Bus to the MR control module.
The MR control module then starts the engine start relay at the starter, which in turn energizes the starter
solenoid switch.
During the start request (tml. 50 over the CAN), the engine start relay is only energized till a certain
engine speed is reached.

Engine start with the start button When an engine start request from the start button has been identified, the MR sends the request over
the CAN bus to the ADM. The ADM sends the engine start request back to the MR as described above.
The engine speed can be raised to rated rpm by operating the start button while the engine is running.
When the start button is released, engine speed returns to idle speed.

Cranking the engine for service operations By simultaneously operating the engine start and stop button, the engine can be cranked on the starter
without starting the engine.

Note:
If the starter has been operated using the start button on the engine, for safety reasons, the engine can
only be started with the drive switch after the ignition has been switched off then on again.

Engine start with CAN bus failure In order to ensure engine starting when there is a fault in the drive switch/ADM connection (tml. 50), or
an ADM control module failure, or discontinuity in the CAN Bus data line, the engine start signal (tml.50)
is also connected directly to the MR control module.
In this way, the engine start relay is actuated directly by the MR control module.

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Starter actuation through the MR 26
 ADM
30 50
15

MR

PPT

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Starter actuation through the MR 27
 Direct starter actuation 07.05.2003

The starter can also be actuated directly.

However, the starter actuation parameter in the

MR must be noted.

ADM

Disadvantages: 30 50
15

Engine start/stop switch on the engine does not

work.

The engine start relay is energized as long as the

ignition key is at the "Start" position.

PPT

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Direct starter actuation 28
 Sub-Menu Homepage

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Direct starter actuation 29
 Telligent engine system 07.05.2003

The engine control (or engine management) system is divided into two subsystems, each with its own control module. The control module of the ADM subsystem
is installed on the vehicle side, and the engine control (MR) subsystem is installed at the engine.

Daimler-Chrysler engines of the 457, 500 and 900 model series are equipped with an MR electronic engine control. All engine specific data are stored in the MR
control module. The MR monitors and defines all the values required for engine operation (for example, start of injection, load condition, ambient conditions,
sensor evaluation, etc.).

Connection to the ADM is over a single-wire enabled CAN bus, which carries the specified values (required torque, required engine speed, etc.) and actual values
(engine speed, coolant, temperature, etc.) in digital form.
The ADM control module contains vehicle-related data (among other things), determines the vehicle operating conditions, and allows driver requirements to be
transferred to the engine side. These requirements may consist of an accelerator pedal action, application of the engine or service brake, or the working speed
control (ADR).

From these, the ADM control module determines the required engine torque or engine speed, and sends it as an engine specified torque or specified engine
speed by the ADR control to the MR. The ADM monitors and defines certain values required for vehicle operation (legally required speed limitation, maximum
working speed, engine brake, etc.). It also provides fault detection, emergency mode functions, and diagnoses.

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Telligent engine system 30
You must be asking, "why have two separate systems"?
Let's look at the reasons, and the advantages this provides.

· Modular structure, so it can be customized and upgraded.

· The drive control also includes 'non-engine' functions and can be configured individually for each variant.

· Vehicle specific data (idle speed, working speed, etc.) are retained in the vehicle if the engine is replaced.

· The engine control module and the data specific to this engine remain with the engine.
They thus remain linked to the engine.

· Reconditioned assemblies always receive the most recent engine data.

· Simpler fault diagnosis, as processes can be assessed individually.

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Telligent engine system 31
 ADM - FR 07.05.2003

ADM-FR function

Mercedes-Benz engines of the 500, 900 and 450 model series are equipped with an MR electronic engine control. The MR monitors and defines all the values
required for engine operation (for example, start of injection, load condition, ambient conditions, sensor evaluation, etc.).

Connection to the vehicle is through a CAN interface, which carries the specified values (required torque, required engine speed, etc.) and actual values (engine
speed, oil pressure, etc.) in digital form.

The adaptation module as vehicle control (ADM-FR) possesses the CAN interface required for the MR, and allows driver requirements to be transferred to the
engine side. The ADM-FR allows the use of conventional display devices, while also providing the conventional interface for special functions.

Switch signals allow the selection of operating statuses pre-defined in the engine control, for example torque and engine speed limits, or the specifying of pre-
defined rpm values.

By parameterization, the routines stored in the control module can be adapted optimally to the type of application. A diagnostic interface is provided for
connecting external diagnostic equipment.

IMPORTANT!
ADM-FR parameters should only be changed after obtaining the approval of the engine installer!

Note:
There is an operator's manual for the ADM-FR, which gives a description of the possible functions, inputs/outputs, required parameter settings, and fault codes.

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ADM - FR 32
Adaptation module as vehicle control (ADM-FR)

ABS Antilock Brake System

ADR Working speed control
BGR Limits
FFG Foot throttle actuator
Driving mode or required rpm
FLA Flame starting system
ISO International Standards Organization
IWA Actual value output (for automatic transmission, customer-
specific electronics)
MBR Engine brake
MR Engine control

N30.14-2023-00

Engine speed signal

The rotational speed signal from the engine electronics is used for regulating the vehicle engine speed. The rpm value is sent over the LS CAN and checked in the
FR electronics for plausibility with the rpm value at terminal W.

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ADM - FR 33
 ADM - 2 07.05.2003

ADM-2 function

Mercedes-Benz engines of the 500, 900 and 450 model series are equipped with an MR electronic engine control. The MR monitors and defines all the values
required for engine operation (for example, start of injection, load condition, ambient conditions, sensor evaluation, etc.).

Connection to the vehicle is through a CAN interface, which carries the specified values (required torque, required engine speed, etc.) and actual values (engine
speed, oil pressure, etc.) in digital form.

The adaptation module as vehicle control (ADM-2) possesses the CAN interface required for the MR, and allows driver requirements to be transferred to the
engine side. The ADM-2 allows the use of conventional display devices, while also providing the conventional interface for special functions.

Switch signals allow the selection of operating statuses pre-defined in the engine control, for example torque and engine speed limits, or the specifying of pre-
defined rpm values.

By parameterization, the routines stored in the control module can be adapted optimally to the type of application. A diagnostic interface is provided for
connecting external diagnostic equipment.

The ADM-2 is connected to an SAE J 1939 CAN bus (high-speed CAN bus) and an additional diagnosis CAN bus.
The ADM-2 is a new development of the ADM-FR.

IMPORTANT!
The ADM-2 parameters should only be changed after obtaining the approval of the engine installer!

Note:
There is an operator's manual for the ADM-2, which gives a description of the possible functions, inputs/outputs, required parameter settings, and fault codes.

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ADM - 2 34
Adaptation module as vehicle control (ADM-2)

ABS Antilock Brake System

ADR Working speed control
ABS/ASR Control module for Antilock Brake System or Acceleration
Slip Regulation
BGR Limits
FFG Foot throttle actuator
Required torque (Drive mode) or required rpm (ADR mode)
FLA Flame starting system
Transmission Control module for the transmission
ISO International Standards Organization
IWA Actual value output
(for automatic transmission, customer-specific electronics)
MBR Engine brake
MR here, PLD-MR = Engine control for the pump-line-nozzle injection
system
Retarder Control module for a retarder
SAE J 1939 Data bus to SAE J 1939 Standard

GT_30_14_0001

Engine speed signal

The rotational speed signal from the engine electronics is used for regulating the vehicle engine speed. The rpm value sent over the LS CAN is checked for
plausibility in the ADM electronic system with the rpm value at terminal W.

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ADM - 2 35
 ADM - AR and FR 07.05.2003

If the engine installer is also installing other MB assemblies, for example if a crane vehicle manufacturer is also installing an MB transmission with EPS (electronic
power shift), the transmission electronics must be able to communicate with the drive control, or must have engine-specific data.
A CAN bus is required for this purpose. In this case, we have the MB commercial vehicle CAN bus, with the related components (excluding instrument cluster),
to fall back on.
However, the MB commercial vehicle FR does not have its own display functions, since it sends all the information required by the driver over the CAN bus to the
electronics system in the instrument cluster.

FR function

The connection between the MR and FR is over a single-wire enabled CAN bus, which carries the specified values (required torque, required engine speed, etc.)
and actual values (engine speed, coolant, temperature, etc.) in digital form.

The FR control module contains vehicle-related data (among other things), determines the vehicle operating conditions, and allows driver requirements to be
transferred over to the engine side.
These requirements may consist of an accelerator pedal action, application of the engine or service brake, or the power take-off control.

From these, the FR control module determines the required engine torque or engine speed, and sends it as the engine specified torque or specified engine speed
by the ADR control to the MR.
The FR monitors and defines certain values required for vehicle operation (for example, legally required speed limitation, maximum working speed, engine brake,
etc.).

The FR does not have its own display functions, and requires information about the current drive status. This is provided over an HS CAN bus, which links the FR
with the other on-board electronic systems (transmission, retarder, etc.).

The FR control module also provides fault detection, emergency mode functions, and diagnoses.

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ADM - AR and FR 36
ADM-AR function

The ADM-AR has the task of transferring all important data to conventional display devices for the operator, and also provides the conventional interface for
special functions.

Switch signals allow the selection of operating statuses pre-defined in the engine control, for example torque and engine speed limits, or the specifying of pre-
defined rpm values.
By parameterization, the routines stored in the control module can be adapted optimally to the type of application. A diagnostic interface is provided for
connecting external diagnostic equipment.

Important!

The FR or ADM-AR parameters should only be changed after obtaining the approval of the engine installer!

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ADM - AR and FR 37
 GT_15_40_0004

Engine speed signal

The rotational speed signal from the engine electronics is used for regulating the vehicle engine speed. The rpm value sent over the LS CAN is checked for
plausibility in the ADM electronic system with the rpm value at terminal W.

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ADM - AR and FR 38
 Sub-Menu Homepage

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ADM - AR and FR 39
 Pedal communication functions of the Mercedes-Benz foot throttle actuator 07.05.2003

Transfer of foot throttle position

The electronic foot throttle actuator transfers two PWM

signals (Pulse Width Modulated). The resulting duty cycle
corresponds to the accelerator pedal position and so
represents the driver's wishes.

Put simply, "PWM" means that the data to be transferred

is represented by the width of the pulse.
When the foot pedal is operated, the pulse varies. The
frequency remains the same (see illustration).

The two signals go in opposite directions. This means

that, in no load position, signal 1 has a low duty cycle,
which rises towards full load. In no-load position, signal 2
has a high duty cycle which decreases towards full load.

A teach-in process is required for the foot throttle

actuator, using Minidiag2.

N07.15-2035-05

Leergas = Idle throttle position

Halbgas = Half-open throttle position
Vollast = Wide open throttle position

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Pedal communication functions of the Mercedes-Benz foot throttle actuator 40
Explanation of pedal range subdivisions

1. The electrical system is the same for all foot throttle Idle throttle adjustment range Wide open throttle adjust-
actuators. ment range
However, the mechanical form of the accelerator pedal 0% 10% 30% 40% 90% 100%
may vary.
Duty cycle
2. 0 % indicates no voltage.
100 % indicates continuous voltage.
The percentage values can be read as actual values on
the Minidiag2. Lower Upper
pedal stop pedal stop
3. The closed throttle position must always be between
10 % and 30 %, otherwise a fault is assumed. 0% Useful pedal range 100%

4. The kickdown position must always be between 40 % Pedal range

and 90 %, otherwise a fault is assumed.
Closed Kickdown-ON position
5. There must be a difference of more than 30% between Throttle position
the closed throttle and the kickdown "On" position, Kickdown-OFF position
otherwise a fault is assumed (accelerate gently). Wide-open position
In wide-open position, the actual value in Minidag2 for
the torque requirement of the foot throttle actuator
must indicate maximum engine torque.

Note:
A teach-in process is required for the foot throttle
actuator, using the test equipment.

N.B.: The kickdown only provides one more item of information, which is evaluated by certain functions such as the cruise control, or limiter.

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Pedal communication functions of the Mercedes-Benz foot throttle actuator 41
 Alternators 07.05.2003

Since March 2001, compact alternators with multifunction controllers have

been installed in all assemblies.
These replace the bowl-type alternators.
There are two versions (Bosch designations):

NCB1-28V 35/80A
NCB2-28V 40/100A

Main advantages of the new alternators:

* Reduced dimensions
* Reduced weight
* Higher maximum rotational speed
* Higher belt drive ratio
* Up to 25 % higher output for the same rotational speed
* Multifunction controller
* Use of Zener rectifier diode Z54

N15.40-2034-11
1 Housing with twin-pipe ventilation 5 Multifunction controller
2 Internal fan 6 External slip rings
3 Stator 7 External rectifier
4 Rotor

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Alternators 42
Information unit

The greatest differences between a compact alternator and the bowl-

type alternator are ...

· ... internal fan

· ... modified connections

· ... multifunction controller.

· ... exciter diodes no longer necessary.

N15.40-2032-11

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Alternators 43
 10 A

GT00_19_0015 N15.40-2033-06
Multifunction controller connection layout Compact alternator functional circuit layout

A3 ADM control module M1 Starter

A6 MR (PLD) control module X8 Positive terminal point
G2 Alternator X9 Ground terminal point

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Alternators 44
> Connections at the multifunction controller

W connection
The voltage signal of an alternator phase can be picked up at the W connection.
The output signal is decoupled from the actual alternator phase and is passed to the exterior through a push-pull end output stage; this means that
the signal at the W terminal is formed in an electronic circuit in the controller and then made available to consumers in the form of a square wave
signal.

L connection
Status indication signal for the alternator/on-board electrical system.

Fault display
The following faults are detected by the FR through this signal, and displayed on the instrument cluster:
* undervoltage (excitation circuit open, alternator stopped, due to broken V-belt for example)
* overvoltage from alternator due to controller fault
* discontinuity at tml. 15

Tml. 15 connection
The "Drive switch ON/OFF" data is sent over terminal 15.

Preexcitation
The preexcitation current is no longer set by the ADM.
Alternator preexcitation occurs when the drive switch or terminal 15 is switched on by the chopped field output stage of the controller.

Alternator deenergizing
The alternator can be deenergized by internal connection of controller input terminal 15 to ground.

Emergency contact (contact broken at Tml. 15)

If contact is broken at terminal 15 and operation is on the battery, the alternator is excited by its own remanence at higher alternator rotational
speeds above 5000 rpm (@ 1500 rpm engine speed).

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Alternators 45
 Sub-Menu Homepage

BS connection
The actual value of the control voltage is detected over the BS connection (Battery Sensor).
Preferably, this is connected to the battery in order to compensate for a voltage drop on the charge line.
At present, on our vehicles, this terminal is connected to starter B+.

Voltage drop on the charge line

If the BS line is connected, the controller can compensate for a voltage drop of DU = 2.5 V.
If there is a voltage difference of DU = 3.5 V ±1 V, a fault indication is generated in the ADM.
For reasons of safety, the control voltage is limited to Umax = 31 V ±1 V.

DFM connection (not used)

The DFM connection supplies the duty cycle of the excitation current, i.e. the capacity utilization of the alternator, in the form of a PWM signal.
The pulse width depends on the operating point of the alternator. The connection must be activated for this purpose.

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Alternators 46
 Homepage

Task 1 m Indicate the point(s) at which you would perform an alternator test.
Discuss this with your group.

Legend:
A3 FR control module
A6 MR (PLD) control module
G2 Alternator
M1 Starter
X8 Positive terminal point
X9 Ground terminal point

GT00_19_0015

What possible fault sources do you find when you examine the voltage supply on terminal 15 at the alternator?

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Alternators 47
 Engine brakes 07.05.2003

Constant throttle

A constant throttle valve is located in each cylinder head, as a 'fifth valve'.

It is actuated pneumatically or hydraulically through the screw-on connection.

The pressure chamber is sealed at the top by an O-ring in the cap.

The cap is fixed to the cylinder head housing by a retaining clip.

Hydraulic actuation (by engine oil pressure) is used only on the OM 906 and
OM 457; but in this case, actuation is by connection to the Turbobrake.
The MR takes over control of the solenoid valve (connected to engine oil
pressure) when a request is sent by the ADM electronics (over the CAN bus).

N01.50-2001-50

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Engine brakes 48
Constant throttle operation

1. When switched on, the constant throttle is open continuously.

2. At the compression stroke (2nd stroke), during the rapid upward movement of the piston from the lower to the upper return point, only a little air escapes into
the exhaust port through the constant throttle, and so the desired compression work is done.

3. During the short pause of the piston at upper TDC, most of the compressed air escapes through the constant throttle into the exhaust port.

4. Without the constant throttle, the next downward movement of the piston (3rd stroke) is assisted by the expansion of the compressed air, and in this way the
compression work of the 2nd stroke is almost fully recovered. In conventional engines, therefore, it makes no significant contribution to power output. In
engines with the constant throttle, on the other hand, the pressure on the piston is considerably lower during the 3rd stroke. The useful difference in
compression and expansion work is therefore substantially higher, and so, therefore, is the contribution to engine power output.

5. The action of the constant throttle, together with the standard engine brake flap, completely prevents undesired re-opening of the exhaust valves. This
considerably relieves the load on the exhaust valves.

6. When the constant throttle is switched on, there is no engine ignition. In order to prevent the engine being switched off inadvertently, for example through a
driver error, the constant throttle and engine brake flap are switched off automatically at engine speeds below 900 rpm.

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Engine brakes 49
 Turbobrake 07.05.2003

N14.15-2053-50

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Turbobrake 50
 N14.15-2052-52

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 N14.15-2062-72 N14.15-2063-72

Turbobrake disengaged Turbobrake engaged

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Turbobrake 52
Notes on the engine head pressure brake function:

The exhaust valve brake applies the same principle as a naturally aspirated compressor.
The turbobrake applies the same principle as a turbo-compressor.
The power required to slow the engine in supercharged mode is brake power.

Method of operation of head pressure brakes:

Four essential factors determine the brake power of head pressure brakes:

· compression pressure at the compression stroke.

The better the cylinder charge, the higher the compression pressure.

· reverse compression at the power stroke

The stronger the pressure release after TDC, the lower the acceleration of the piston due
to release of the pressure in the previously compressed air (constant throttle function).

· head pressure in the gas exchange system.

The higher the head pressure, the more power is required for gas exchange. The head pressure
in the exhaust pipe must be limited in order to prevent undesired opening of the valves.

· rate of air flow.

The larger the air volume that is moved under pressure, the more power is absorbed.

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Turbobrake 53
With the exhaust valve brake, the supercharger runs on idle during brake operation. The cylinder charge corresponds to that of a naturally
aspirated engine, or is even poorer, because in this case the supercharger impedes the intake process.

With the Turbobrake, the supercharger ensures good cylinder charging. The sliding sleeve has molded slits on the turbine side and
narrows the cross-section at the inlets for the turbine, and guides the air stream directly towards the outer area of the turbine blades.
The delivered volume of air is the same as or greater than in fuel combustion operation, thus achieving optimal cylinder charge, or a
very high compression pressure. This is why the charge air pressure or turbocharger rotational speed must be controlled in engine
brake operation. The rate of air flow in engine brake operation is raised, and the engine is under lower thermal load than with the valve brake.

A controlled bypass connects the twin-pipe turbine with the turbine outlet (for the wastegate function), and the head pressure or
turbine rotational speed can be controlled.
The Turbobrake is also used by the brake speed control.

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Turbobrake 54
Engine brake control

Constant throttle in connection with the Turbobrake:

The constant throttle valves are operated hydraulically by engine oil pressure.
At engine speed over 900 rpm and coolant temperature > 60°, the MR (proportioning valve 2) energizes the solenoid valve at the oil filter housing.
A line goes from the oil filter housing to the cylinder heads, and the constant throttle valves are opened by the engine oil pressure (hydraulically).

Comment: The operation of the hydraulic constant throttle on the OM 457 depends on engine speed and coolant temperature. In general,
if coolant temperature is above > 60°, the constant throttle is in operation.

Turbobrake:

When starting, the MR (proportioning valve 1) energizes the EPW solenoid valve (with a PWM signal), at which the pneumatic
reservoir pressure from the ancillary consumer circuit is present.
This valve allows pneumatic pressure through (about 5 bar) and the rod in the vacuum cell at the Turbobrake is extended.
The rotary valve in the Turbobrake is rotated and the bypass between the turbine and turbine outlet is closed (there is no wastegate function).

At engine speeds over 900 rpm, the Turbobrake can be engaged.

The FR energizes the engine brake solenoid valve. The pneumatic cylinder extends and the sliding sleeve is pushed into the Turbobrake by
the actuating arm.
The turbo speed increases.
On the shaft linking the turbine wheel to the compressor turbine wheel is an rpm sensor (induction-type pulse generator), which indicates
the turbine speed to the MR.

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Turbobrake 55
If the speed reaches 85,000 - 90,000 rpm, the solenoid valve (EPW) vents the vacuum cell. The spring in the vacuum cell pushes the
rod back, and the rotary valve turns in the blow-off direction (part of the exhaust gases now bypass the turbine).
The speed is maintained at 85,000 - 90,000 rpm.
The vacuum cell can be vented down to 0 bar with the solenoid valve (EPW).

There is an electronic circuit in the solenoid valve (EPW), which measures pressure and atmospheric pressure.
If the engine is stopped, the vacuum cell is vented down to 0 bar with the solenoid valve (safety circuit, bypass fully open).

The turbocharger rotational speed can be read off in the MR actual values.
The proportioning valve 1 parameter in the MR must be set to "active".
In the "Actuations" menu in Star Diagnosis, the solenoid valve for the sliding sleeve cylinder or the EPW solenoid valve can be
actuated in the FR or MR.

Turbobrake MR wiring diagram

Rotary
valve
B104

MV 4
1 2

(EPW) 3

Y 87 1

N3 N3 N3 N3 N3 N3
11 51 12 24 5 4

MR
N3=55-pin plug
at the MR Turbobrake PPT

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Note:

· The flame starting system does not operate if the engine is started before the "Flame starting system" indicator lamp goes off.
· If the coolant temperature goes above -4°C approximately, the "Flame starting system" indicator lamp goes off after about 2 seconds (function check).
· If the coolant temperature goes under -4°C approximately, the "Flame starting system" indicator lamp goes off after about 20 seconds.

Faults in the flame starting system are indicated on the display by means of a warning light and a fault code. Have the flame starting system inspected at a
Mercedes-Benz service station.
If the engine coolant temperature sensor fails, the flame starting system electronics use the engine oil temperature instead.

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The Turbobrake is switched on and off by the FR. Non-operation of the Turbobrake may also be caused
by another vehicle system, for example the ASR or ABS.
· Clutch pedal teach-in error in the FR or GC, or teach-in not performed.
· The accelerator pedal is actuated.
· Faulty engine brake solenoid.
· Where necessary, the FR calculates engine brake power and sends it to the MR.

The MR controls the wastegate function. Non-operation may be due to causes in the engine components.
· Faulty boost pressure sensor (substantial loss of engine brake power).
· Faulty boost pressure rpm sensor (substantial loss of engine brake power).
· Faulty EPW valve (sporadic or no engine power, low engine brake power)
· Wiring fault
· Hardware fault

Turbobrake function is also affected by the pneumatic system.

· Pressure in the ancillary consumer circuit.
· Leaktightness of pneumatic lines
· Easy movement of the engine brake cylinder, vacuum cell, and Turbobrake mechanical system

Checking the function (not power output) of the Turbobrake without test equipment.

Always perform the check with the engine at operating temperature.

Switch on the ignition. Engage the highest stage of the engine brake.
An assistant starts the engine using the starter button on the engine. During the starting procedure, the rod in
the vacuum cell is reset (no wastegate function).
The assistant accelerates the engine using the starter button on the engine. The engine begins to 'hunt'.
Check visually whether the sliding sleeve fork moves and whether the rod in the vacuum cell is reset.
When the engine is switched off, the rod in the vacuum cell must be reset again (wastegate in full operation).

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 Sub-Menu Homepage

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Turbobrake 59
 Flame starting system 07.05.2003

The flame starting system consists of a diagnostics-enabled electronics system (which is linked over a Low-Speed CAN bus in the ADM with the engine CAN bus,
or joined with the engine CAN bus through the plug in the ADM), a solenoid valve, a glow plug, and a fuel nozzle.
The fuel is supplied over a line (with throttle) from the fuel filter to the solenoid valve, and then to the fuel nozzle. The fuel nozzle atomizes the fuel, which is then
ignited at the glow plug and thus heats the intake air.

Flame starting system:

The flame starting system is a cold-starting aid, for when outside temperatures are low.

At coolant temperatures below -4°C approximately, the flame starting system reduces pollutant
emissions (after the engine is started). This also spares the starter and battery and shortens the
starting time. Therefore, the engine should only be started after the "Flame starting system"
indicator lamp goes off.

· Turn the ignition switch to Ignition "On". The "Flame starting system" indicator lamp must light up.
· Start the engine within 30 seconds after the "Flame starting system" indicator lamp goes off.

1 Flame starting system indicator lamp N54.30-4365-20

The flame starting system switches off automatically:

· if the engine is not started within 30 seconds after the "Flame starting system" indicator lamp goes off,
· if the engine is started while the indicator lamp is lit,
· if the coolant temperature reaches about 0°C with the engine running.

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Note:

· The flame starting system does not operate if the engine is started before the "Flame starting system" indicator lamp goes off.
· If the coolant temperature goes above -4°C approximately, the "Flame starting system" indicator lamp goes off after about 2 seconds (function check).
· If the coolant temperature goes under -4°C approximately, the "Flame starting system" indicator lamp goes off after about 20 seconds.

Faults in the flame starting system are indicated on the display by means of a warning light and a fault code. Have the flame starting system inspected at a
Mercedes-Benz service station.
If the engine coolant temperature sensor fails, the flame starting system electronics use the engine oil temperature instead.

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 Heater flange in Mercedes-Benz engines 07.05.2003

Since the flame starting system cannot be used at high altitudes (due to lack of oxygen), a heater flange is installed in the engine intake manifold.

Version 1: Installed with FR and ADM-FR

The preheating unit is switched on separately using the switch À.

The indicator lamp Á lights up = start of preheating.

The heater flange Ä is then actuated by the control module  and supplied with current through the power relay Ã.

Preheating time depends on voltage and lasts for about 30 seconds at 21 V.

When the preheating time is ended, the indicator lamp Á flashes, indicating ready-to-start (this lasts about 30 s).

When the starting time has ended, and terminal 50 is 'Off'; the post-heating time begins. This depends on temperature, and lasts about 120 seconds at -4°C to -
10°C, 150 seconds at about -10°C, and 180 seconds at -20°C and under.

After starting, the indicator lamp Á is no longer lit.

The relay Æ cuts off the current to the heater flange while the starter is engaged.

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Electric intake heater flange (24 V) without load detection

GT_15_45_0002

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Electric intake heater flange (24 V) with load detection

GT_15_45_0001

Resistor 7 is used as the load detection for heater flange 5. If the heater flange fails, indicator lamp 2 indicates the fault with a flash code.

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Version 2: installed with ADM-2

At coolant temperatures below -4°C and at about 1000 mbar, the ADM-2 electronics automatically switch the relay and the heater flange begins to heat up.
The switching depends on coolant temperature and atmospheric pressure. At lower atmospheric pressure, the heater flange is switched on more quickly.

· Turn the ignition switch to "Ignition On". The "Flame starting system" indicator lamp must light up.

· Start the engine within 30 seconds after the "Heater flange" indicator lamp goes off.

· The ADM-2 electronics cut off the current to the relay during the starting procedure.

The heater flange switches off automatically:

· if the engine is not started within 30 seconds after the "Heater flange" indicator lamp goes off,

· if the engine is started while the indicator lamp is lit,

· if the coolant temperature reaches about -3°C at about 1000 mbar with the engine running.

Notes:

· The heater flange does not operate if the engine is started before the indicator lamp goes off.

· If the coolant temperature goes above -4°C approximately, the indicator lamp goes off after about 2 seconds (function check).

· The indicator lamp flashes if the Make contact in the relay remains stuck.

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Electric intake heater flange (24 V) with load detection

21/7

GT_15_45_0003

The indicator lamp flashes if the Make contact in the relay remains stuck.

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» ... Die Mitarbeiter werden zukünftig in die Rolle persönlicher Wissensmanager hineinwachsen
müssen, die aktiv die Verantwortung für ihre Qualifizierung übernehmen ... « Jürgen E. Schrempp

» ... Staff must in future assume the role of personal knowledge managers, who actively take
responsibility for their own qualification ... « Jürgen E. Schrempp

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