Service Information

Mack Trucks, Inc.

Electronically Controlled Suspension

(ECS) Diagnostic Trouble Codes, MID150

Group 61
Release 01

CHU, CXU 6X2

 Foreword

The descriptions and service procedures contained in this manual are based on designs and
methods studies carried out up to October 2012.
The products are under continuous development. Vehicles and components produced after the
above date may therefore have different specifications and repair methods. When this is believed
to have a significant bearing on this manual, supplementary service bulletins will be issued to cov-
er the changes.
The new edition of this manual will update the changes. In service procedures where the title in-
corporates an operation number, this is a reference to an M. S. T. Service procedures which do
not include an operation number in the title are for general information and no reference is made
to an M. S. T.
Each section of this manual contains specific safety information and warnings which must be re-
viewed before performing any procedure. If a printed copy of a procedure is made, be sure to also
make a printed copy of the safety information and warnings that relate to that procedure. The fol-
lowing levels of observations, cautions and warnings are used in this Service Documentation:
Note: Indicates a procedure, practice, or condition that must be followed in order to have the ve-
hicle or component function in the manner intended.
Caution: Indicates an unsafe practice where damage to the product could occur. Warning: Indi-
cates an unsafe practice where personal injury or severe damage to the product could occur.
Warning: Indicates an unsafe practice where personal injury or severe damage to the product
could occur.
Danger: Indicates an unsafe practice where serious personal injury or death could occur.

Note: Information is subject to change without notice. Illustrations used are for reference only and
may differ slightly from the actual vehicle being serviced. However, key components addressed in
this information are represented as accurately as possible.

Order number: PV776-89115756

©2013 Mack Trucks, Inc., Greensboro, NC USA

All rights reserved. No part of this publication may be reproduced, stored in retrieval system, or
transmitted in any forms by any means, electronic, mechanical, photocopying, recording or other-
wise, without the prior written permission of Mack Trucks, Inc.

USA60108
General..........................................................................................................................................1
Location of Components, ECS ...........................................................................................................1

Specifications ................................................................................................................................3

Tools .............................................................................................................................................5

System check ................................................................................................................................1

MID 150 SID 4/7 Solenoid Valve Assembly, Drive Axle...........................................................................3
7281–21–03–03...............................................................................................................................5
MID 150 SID 5/8 Solenoid Valve Assembly, Extra Axle...........................................................................8
7281–21–03–04............................................................................................................................. 10
MID 150 SID 18 Level Sensor .......................................................................................................... 13
7281–21–03–06............................................................................................................................. 16
MID 150 SID 24/26 Pressure Sensor................................................................................................. 19
7281–21–03–08............................................................................................................................. 22
MID 150 SID 231 SAE J1939 Control Link.......................................................................................... 25
MID 150 SID 240 Program Memory................................................................................................... 26
MID 150 SID 250 SAE J1708 Information Link .................................................................................... 27
MID 150 SID 253 Calibration Memory, EEPROM................................................................................. 28
MID 150 PSID 1 Level Sensor Voltage Supply .................................................................................... 29
MID 150 PSID 2 Pressure Sensor Voltage Supply ............................................................................... 30
MID 150 PSID 3 Air Suspension Manual Control Switch ....................................................................... 31
7281–21–03–01............................................................................................................................. 32
MID 150 PSID 8 Calibration Memory Load Indicator ............................................................................ 34
MID 150 PSID 200 J1939 Data link Interruption, Vehicle ECU ............................................................... 36
MID 150 PSID 201 J1939 Data link Interruption, Vehicle ECU ............................................................... 37
MID 150 PSID 202 J1939 Data link Interruption, Vehicle ECU ............................................................... 38
MID 150 PSID 204 J1939 Data Link Abnormal Update Rate, MID 136 ABS ECU ..................................... 39
MID 150 PSID 210 J1939 Data link Interruption, Control unit External Lighting......................................... 40
Operation Numbers ........................................................................................................................ 41
Group 728 Location of Components, ECS

General
Location of Components, ECS

Location of Components on Vehicle

1 ECS Electronic Control Unit

The ECS Electronic Control Unit is mounted on a rack. It is
located inside the vehicle cab behind the instrument cluster
in the dashboard. It is not a sealed unit and must be pro-
tected from the elements.

2 Level Sensor
The level sensor is located on the passenger side (RIGHT)
frame rail (inside) between the drive axle and the tag axle.

3 Pressure sensors
The 2 pressure sensors are located on top of the suspension
air bags on the drive and tag axle. They are accessible from
the left side (driver’s side) of the vehicle. They measure the
air pressure supplied by both the tag axle and the driven axle
suspension air bags. They supply a signal to the ECS control
unit.

4 Solenoid Valve Package, Drive Axle

The drive axle solenoid is located on the driver’s side frame
rail (inside) in front of the intermediate frame cross member.

5 Solenoid Valve Package, Tag Axle

The tag axle solenoid is located on the driver’s side frame
rail (inside) between the intermediate frame cross member
and the drive axle. The tag axle is often referred to as the bo-
gie axle.

Location of Components in Cab

There are two ECS control switches mounted in the center dash
panel between the parking and trailer air supply and the ventila-
tion outlet.

• ECS ON / OFF Switch — This is a rocker switch. Flipping it

DOWN (the ON position) allows the vehicle to be raised and
lowered manually.
Flipping the ECS ON / OFF Switch Up (the OFF position) will
return the vehicle to the normal ride height.

• ECS UP / DOWN Switch(Right Switch) (Press and Hold) —

This switch raises or lowers the rear suspension.

1
Group 728 Ride Height Warning System

Ride Height Warning System

This system will activate if the vehicle is not returned to normal
drive height and it is driven from a stop. At approximately 13
kilometers per hour (8 miles per hour), a flashing icon symbol
will appear on the dashboard display.

If the vehicle continues to gain speed, at approximately 26 kilo-

meters per hour (16 miles per hour), and audible warning indi-
cator will sound.

Blocked Mode, ECS

When the control module has detected a fault in any of the cen-
tral valves (the valve in a solenoid valve package connected to
the pressure tank) or in the pressure sensors the system
switches to blocked mode. Blocked mode means that the auto-
matic drive position control ceases completely.

The fault codes in the ECU resulting from the blocked mode
must be cleared by resetting the ECU. To reset the ECU, use
Premium Tech Tool (PTT) and then cycle the ignition key. The
ignition key must be cycled OFF — DRIVE — OFF and back to
the DRIVE position.

2
Group 728 Signal Description, ECS

Specifications
Signal Description, ECS
Air Suspension, Breakout Box
Connected between Control Unit
and Cable Harness
Conditions
• Breakout box 9998699 and adapter 9813194 connected be- • Control unit connected.
tween control unit connector X 1 on ECU and the cable • Starter key in drive position.
harness.
• Voltage measurement with multimeter 88890074.
• Breakout box 9998699 and adapter 9998533 connected be-
U = DC volts (V); Ubat = battery voltage; R = resistance in
tween control unit connector X 2 on the ECU and the cable
harness. ohms.

Terminal Signal Type Measurement Nominal Value Other

Points
X1:01 Switch, Suspension Control, UP X1:01 -X1:11 U ≈ Ubat (inactive) U < 0.5V
(active)
X1:05 Solenoid Valve, Drive Axle Deflating X1:05 -X1:11 U ≈ 0 V (inactive) U ≈ Ubat
(active)
X1:07 Pressure Sensor, Ground Terminal X1:07 -X1:11 U ≈ 0V
X1:11 Level Sensor, Ground terminal X1:11 -X1:7 U ≈ 0V
X1:15 Switch, Suspension Control, Down X1:15 -X1:11 U ≈ Ubat (inactive) U < 0.5V
(active)
X1:17 Level sensor, supply voltage X1:17 -X1:11 U ≈ 3.5 -5.5 V
X1:21 Pressure Sensor, Tag Axle, Signal X1:21 -X1:11 U ≈ 0.2 -4.8 V
Voltage
X1:23 Pressure Sensor, Right Rear X1:23 -X1:11 U ≈ 0.2 -4.8 V
X1:28 Level Sensor, Signal Voltage X1:28 -X1:11 U ≈ 0.5 -4.5 V
X1:30 Pressure Sensor, Supply voltage X1:30 -X1:11 U ≈ 3.5 -5.5 V
X2:01 SAE J1708 Information Link B X2:1 -X2:22 U ≈ 0-5 V 401–A
X2:02 Control Unit, Supply Voltage from Relay X2:2 -X2:22 U ≈ Ubat
X2:03 Control Unit, Ground Terminal X2:03 -X2:22 U ≈ 0V
X2:04 Control Unit, Supply Voltage, DR X2:04 -X2:22 U ≈ Ubat (active) U ≈ 0 V
Position (inactive)
X2:05 Control Unit, Relay Supply Voltage X2:05 -X2:22 U ≈ Ubat (active) U ≈ 0 V
(inactive)
X2:08 Solenoid Valve, Tag Axle, Inflating X2:08 -X2:22 U ≈ 0 V (inactive) U ≈ Ubat
(active)
X2:09 Solenoid Valve, Tag Axle, Deflating X2:09 -X2:22 U ≈ 0 V (inactive) U ≈ Ubat
(active)
X2:10 Solenoid Valve, Drive Axle Inflating X2:10 -X2:22 U ≈ 0 V (inactive) U ≈ Ubat
(active)
X2:11 SAE J1708 Information Link A X2:11 -X2:22 U ≈ 0-5 V 400–A
3
Group 728 Conditions

X2:12 Control Unit, Supply Voltage from Relay X2:12 -X2:22 U ≈ Ubat
X2:13 SAE J1939 control link B X2:13 -X2:22 U ≈ 0-3 V 407–A
X2:14 SAE J1939 control link A X2:14 -X2:22 U ≈ 2-5 V 406–A
X2:15 Switch, Suspension Control ON/OFF X2:15 -X2:22 U ≈ Ubat (inactive) U < 0.5V
(active)
X2:22 Control Unit, Ground Terminal X2:22 -X2:3 U ≈ 0V

4
Group 728 Special Equipment

Tools
Special Equipment
For information on ordering special tools, please refer to the
special tools information, in group 08.

Special Tools and Other Special Equipment

Tool Number Tool Description
9998533 Adapter for control unit, connector X2 (22 pin)
88890039 Adapter, 4–pin DIN
9998699 Breakout Box (62–pin)
88890074 Multimeter for voltage and resistance measurements
J47287 Adapter cable for checking pressure transducer
9813194 Adapter for control unit, connector X1 (30–pin)
85104407 Overlay, 62–pin. Used with tool 9813194
85104406 Overlay, 62–pin. Used with tool 9998533

5
Group 728 Troubleshooting

System check
Troubleshooting
MID 150 Diagnostic Trouble Code SID:
Subsystem Identification Description (identification of
component).
PSID:
MID: Proprietary Subsystem Identification Description (Volvo unique
Message Identification Description (identification of control component identification)..
unit).
FMI::
PID: Failure Mode Identifier (identification of fault type).
Parameter Identification Description (identification of parameter
[value]). For more detailed information concerning these designations,
see information in Group 3.
PPID:
Proprietary Parameter Identification Description (Mack unique
identification of parameter [value]).

Fault Code Component / function FMI Section

MID 150 SID 4 Solenoid valve, left rear 5, 6, 7 “MID 150 SID 4/7 Solenoid Valve Assembly, Drive Axle” page 3
MID 150 SID 5 Solenoid valve, extra axle 5, 6, 7 “MID 150 SID 5/8 Solenoid Valve Assembly, Extra Axle” page 8
MID 150 SID 7 Solenoid valve, central 5, 6, 7 “MID 150 SID 4/7 Solenoid Valve Assembly, Drive Axle” page 3
MID 150 SID 8 Solenoid valve, central 5, 6, 7 “MID 150 SID 5/8 Solenoid Valve Assembly, Extra Axle” page 8
bogie
MID 150 SID 18 Level sensor, right rear 2, 3, 4, 7 “MID 150 SID 18 Level Sensor” page 13
MID 150 SID 24 Pressure sensor, right rear 2, 3, 4, 7 “MID 150 SID 24/26 Pressure Sensor” page 19
MID 150 SID 26 Pressure sensor, extra axle 2, 3, 4, 7 “MID 150 SID 24/26 Pressure Sensor” page 19
MID 150 SID SAE J1939 Control link 2 “MID 150 SID 231 SAE J1939 Control Link” page 25
231
MID 150 SID Program memory 13 “MID 150 SID 240 Program Memory” page 26
240
MID 150 SID Information link SAE J1708 2 “MID 150 SID 250 SAE J1708 Information Link” page 27
250
MID 150 SID Parameter memory 2, 13 “MID 150 SID 253 Calibration Memory, EEPROM” page 28
253
MID 150 PSID 1 Level sensor, supply 3, 4 “MID 150 PSID 1 Level Sensor Voltage Supply” page 29
voltage
MID 150 PSID 2 Pressure sensor, power 3, 4, 14 “MID 150 PSID 2 Pressure Sensor Voltage Supply” page 30
supply
MID 150 PSID 3 Bogie switch 7 “MID 150 PSID 3 Air Suspension Manual Control Switch” page 31
MID 150 PSID 8 Calibration memory, load 13, 14 “MID 150 PSID 8 Calibration Memory Load Indicator” page 34
indicator
MID 150 PSID SAE J1939 Control link, 9 “MID 150 PSID 200 J1939 Data Link Interruption, Vehicle ECU”
200 MID 128 page 36
MID 150 PSID SAE J1939 Control link, 9 “MID 150 PSID 201 J1939 Data Link Interruption, Vehicle ECU”
201 MID 144 page 37

1
Group 728 FMI Table

MID 150 PSID SAE J1939 Control link, 9 “MID 150 PSID 202 J1939 Data Link Interruption, Instrument ECU”
202 MID 1240 page 38
MID 150 PSID SAE J1939 Control link, 9 “MID 150 PSID 204 J1939 Data Link, Abnormal Update Rate, APS
204 MID 136 ECU” page 39
MID 150 PSID SAE J1939 Control link, 9 “MID 150 PSID 210 J1939 Data Link Interruption, Control Unit Ex-
210 MID 216 ternal Lighting” page 40

FMI Table
SAE Standard

FMI Display Text SAE Text

0 Value too high Data applicable, but above normal working range.
1 Value too low Data applicable, but below normal working range.
2 Incorrect data Intermittent or incorrect data.
3 Electrical fault Abnormally high voltage or short-circuit to higher voltage.
4 Electrical fault Abnormally low voltage or short-circuit to lower voltage.
5 Electrical fault Abnormally low current or open circuit.
6 Electrical fault Abnormally high current or short-circuit to Ground.
7 Mechanical fault Incorrect response from the mechanical system.
8 Mechanical or electrical fault Abnormal frequency.
9 Communication fault Abnormal update rate.
10 Mechanical or electrical fault Abnormally high variations
11 Unknown fault Unidentifiable fault.
12 Component fault Defective unit or component.
13 Incorrect calibration Values outside calibration values.
14 Unknown fault Special instructions.
15 Unknown fault Reserved for future use.

2
Group 728 MID 150 SID 4/7 Solenoid Valve Assembly, Drive Axle

MID 150 SID 4/7 Solenoid Valve Assembly, Drive Axle

General Information
When the electronic control unit has discovered a fault in the
central valve the system is set to the blocked mode, see
“Blocked Mode, ECS” page 5 .

Component: Y25 Solenoid valve unit, levelling system, air

suspension

SID Explanation
4 Drive Axle Solenoid
7 Central Valve Drive Axle

Fault code
FMI 5
Abnormally low current or open circuit.

Conditions for fault code:

• Abnormally low current or open circuit

Possible cause:
• Break in supply cable.
• Break in Ground lead.
• Faulty solenoid valve.

Reaction from the control unit:

• Fault code set.
• The system is set to the block mode if the central solenoid
valve (SID 7) sets the fault code.

Noticeable external symptoms:

• Warning lamp
• The vehicle has either continuous control or no control at all.

Appropriate check:
• “MID 150 SID 4/7 Solenoid Valve Assembly Drive Axle,
Check”

FMI 6
Abnormally high current or short-circuit to Ground.

Conditions for fault code:

• Abnormally high current or short circuit to Ground.

Possible cause:
• Short-circuit to power supply on the Ground lead. .
• Faulty solenoid valve.

3
Group 728 Reaction from the control unit:

Reaction from the control unit:

• The system is set to the block mode if the central solenoid
valve (SID 7) sets the fault code.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally

Appropriate check:
• “MID 150 SID 4/7 Solenoid Valve Assembly Drive Axle,
Check”

FMI 7
Incorrect response from the mechanical system

Conditions for fault code:

• The solenoid valve does not empty / fill as it should.
• Pressure sensor not registering any change.

Possible cause:
• The solenoid valve has stuck (mechanically) in the open /
closed position.
• Air leakage.
• Defective pressure sensor.

Reaction from the control unit:

• The system is set to the block mode if the central solenoid
valve (SID 7) sets the fault code.
• If any solenoid valve other than the central valve sets the
fault code:
If the solenoid valve is closed, the system has no control.
If the solenoid valve is open, the system has continuous
control.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 SID 4/7 Solenoid Valve Assembly Drive Axle,
Check”
• “Pressure Sensor, Check”.
• Check that air bags are emptied/filled correctly by putting the
vehicle in blocked mode, see “Blocked Mode, ECS”

4
Group 728 7281–21–03–03

7281–21–03–03
MID 150 SID 4/7 Solenoid Valve Assembly Drive Axle, Check
Special tools and Equipment required
Tool Identification Tool Description
Number
9998533 Adapter for control unit, connector
X2 (22 pin)
88890039 Adapter, 4–pin DIN
9998699 Breakout Box (62–pin)
88890074 Multimeter
9813194 Adapter for control unit, connector
X1 (30–pin)

Note: Read off the other fault codes for the ECS system. If any
of the other solenoid valves also have an active fault code, the
fault is most likely located on one of the common cables, see
wiring diagram.
Check all the relevant connectors for bad contact, contact re-
sistance and oxidation. For a more detailed description of fault
tracing cables and connectors, see information in Group 3.

Tests that can be carried out with the PC tool

The following tests are useful for a closer examination of the
solenoid valve function:

“7289–08–03–04 Solenoid valves, test”

Measurement at the component between the connector and the control unit
Note: If one of the values below is incorrect this could also have
caused the component to break down, in which case the com-
ponent must be checked.

Power supply cable:

Conditions:
• Adapter 88890039 connected between solenoid valve pack-
age and cable harness.
• Voltage measurement with multimeter 88890074.
• Starter key in drive position.
SID Measure- Nominal Value
ment
points
4 2–4 U ≈ 0 V (inactive) U ≈ Ubat (active)
7 1– 4 U ≈ 0 V (inactive) U ≈ Ubat (active)
Special Tools: 88890039, 88890074

5
Group 728 Ground cable:

Ground cable:
Conditions:
• Adapter 88890039 connected between solenoid valve pack-
age and cable harness.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
Measurement points Nominal Value
4 — Ground R = 0 ohms
Special Tools: 88890039, 88890074

Checking component
Note: Faults in the component may be caused by faults in the
cable harness for the control unit. Check the cable harness be-
fore connecting a new component.

Conditions:
• Adapter 88890039 connected on the component side but not
on the cable harness side.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
SID Measure- Nominal Value
ment
points
4 2–4 R = 50 — 80 ohms
7 1– 4 R = 50 — 80 ohms
Special Tools: 88890039, 88890074

6
Group 728 Checking sub-systems

Checking sub-systems
Conditions:
• Breakout box 9998699 and adapter 9813194 connected be-
tween control unit connector X1 and the cable harness.
Note: The terminals are positioned in order between 1-30 on
the breakout box.

• Breakout box 9998699 and adapter 9998533 connected be-

tween control unit connector X2 and the cable harness.
Note: The terminals are positioned in order between 31-52
on the breakout box.

• Voltage measurement with multimetet 88890074.

• Starter key in drive position.
SID Measure- Nominal Value
ment
points
4 X1:05 — U ≈ 0 V (inactive) U ≈ Ubat (active)
X2:22
7 X2:10 — U ≈ 0 V (inactive) U ≈ Ubat (active)
X2:2
Special Tools: 9998699 x 2, 9813194, 9998533, 88890074

Mechanical checks
The following Service Bulletin is useful for examining what the
cause of a mechanical fault may be:

• Fault-tracing, Symptom, Electronically controlled air suspen-

sion”, see information in Group 7.

Verification
To check that the fault is remedied use the test in the PC tool
(see “Tests that can be carried out with the PC tool”) or “Fault
tracing, ECS, Function test”, see information in Group 7.

7
Group 728 MID 150 SID 5/8 Solenoid Valve Assembly, Extra Axle

MID 150 SID 5/8 Solenoid Valve Assembly, Extra Axle

General information
Component: Y 29 Solenoid valve unit, tag axle

SID Explanation
5 Extra Axle / Tag Axle
8 Central Valve Extra Axle

Fault code
FMI 5
Abnormally low current or open circuit.

Conditions for fault code:

• Abnormally low current or open circuit.

Possible cause:
• Break in supply cable.
• Break in the Ground lead.
• Faulty solenoid valve.

Reaction from control unit:

• Fault code set.
• The system is set to the blocked mode if the central valve
(SID 8) sets an fault code.

Noticeable external symptoms:

• Warning lamp
• The vehicle has either continuous control or no control.

Appropriate check:
• “MID 150 SID 5/8 Solenoid Valve Assembly Extra Axle”
FMI 6
Abnormally high current or short-circuit to Ground.

Conditions for fault code:

• Abnormally high current or short circuit to Ground.

Possible cause:
• Short-circuit to power supply on the Ground lead. .
• Faulty solenoid valve.

Reaction from the control unit:

• The system is set to the block mode if the central solenoid
valve (SID 7) sets the fault code.

Noticeable external symptoms:

• Warning lamp • The vehicle may lean abnormally
8
Group 728 Appropriate check:

Appropriate check:
• “MID 150 SID 5/8 Solenoid Valve Assembly Extra Axle,
Check”

FMI 7
Incorrect response from the mechanical system

Conditions for fault code:

• The solenoid valve does not empty / fill as it should.
• Pressure sensor not registering any change.

Possible cause:
• The solenoid valve has stuck (mechanically) in the open /
closed position.
• Air leakage.
• Defective pressure sensor.

Reaction from the control unit:

• The system is set to the block mode if the central solenoid
valve (SID 8) sets the fault code.
• If any solenoid valve other than the central valve sets the
fault code:
If the solenoid valve is closed, the system has no control.
If the solenoid valve is open, the system has continuous
control.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 SID 5/8 Solenoid Valve Assembly ExtraAxle,
Check”
• “Pressure Sensor, Check”.
• Check that air bags are emptied/filled correctly by putting the
vehicle in blocked mode, see “Blocked Mode, ECS” page 5

9
Group 728 7281–21–03–04

7281–21–03–04
MID 150 SID 5/8 Solenoid Valve Assembly Extra Axle, Check
Special tools and Equipment required
Tool Identification Tool Description
Number
9998533 Adapter for control unit, connector
X2 (22 pin)
88890039 Adapter, 4–pin DIN
9998699 Breakout Box (62–pin)
88890074 Multimeter
9813194 Adapter for control unit, connector
X1 (30–pin)

Note: Read off the other fault codes for the ECS system. If any
of the other solenoid valves also have an active fault code, the
fault is most likely located on one of the common cables, see
wiring diagram.
Check all the relevant connectors for bad contact, contact re-
sistance and oxidation. For a more detailed description of fault
tracing cables and connectors, see information in Group 3.

Tests that can be carried out with the PC tool

The following tests are useful for a closer examination of the
solenoid valve function:

“7289-08-03-04 Solenoid valves, test”

Measurement at the component between the connector and the control unit
Note: If one of the values below is incorrect this could also have
caused the component to break down, in which case the com-
ponent must be checked.

Power supply cable:

Conditions:
• Adapter 88890039 connected between solenoid valve pack-
age and cable harness.
• Voltage measurement with multimeter 88890074.
• Starter key in drive position.
SID Measure- Nominal Value
ment
points
4 2–4 U ≈ 0 V (inactive) U ≈ Ubat (active)
Note: Listen for clicking sound when
the solenoid valve is activated.
7 1– 4 U ≈ 0 V (inactive) U ≈ Ubat (active)
Special Tools: 88890039, 88890074

10
Group 728 Ground cable:

Ground cable:
Conditions:
• Adapter 88890039 connected between solenoid valve pack-
age and cable harness.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
Measurement points Nominal Value
4 — Ground R = 0 ohms
Special Tools: 88890039, 88890074

Checking component
Note: Faults in the component may be caused by faults in the
cable harness for the control unit. Check the cable arness be-
fore connecting a new component.

Conditions:
• Adapter 88890039 connected on the component side but not
on the cable harness side.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
SID Measure- Nominal Value
ment
points
5 2–4 R = 50 — 80 ohms
8 1– 4 R = 50 — 80 ohms
Special Tools: 88890039, 88890074

Checking sub-systems
Conditions:
• Breakout box 9998699 and adapter 9998533 connected be-
tween control unit connector X 2 and the cable harness.
• Voltage measurement with multimetet 88890074.
• Starter key in drive position.
SID Measure- Nominal Value
ment
points
5 X2:09 — U ≈ 0 V (inactive) U ≈ Ubat (active)
X2:22
8 X2:08 — U ≈ 0 V (inactive) U ≈ Ubat (active)
X2:2
Special Tools: 9998699, 9998533, 88890074

Mechanical checks
The following Service Bulletin is useful for examining what the
cause of a mechanical fault may be:

• Fault-tracing, Symptom, Electronically controlled air suspen-

sion”, see information in Group 7.
11
Group 728 Verification

Verification
To check that the fault is remedied use the test in the PC tool
(see “Tests that can be carried out with the PC tool”) or “Fault
tracing, ECS, Function test”, see information in Group 7.

12
Group 728 MID 150 SID 18 Level Sensor

MID 150 SID 18 Level Sensor

General information
The rear axle level sensor can be positioned on either the left or
the right side of the vehicle, depending upon the variant but is
always designated B 28.

When the control unit has discovered a fault on any of the level
sensors the system is set to the blocked mode, see “Blocked
Mode, ECS” page 5 .

Component:

SID Component Number Component

18 B 30 A Level sensor, rear axle
right

Fault code
FMI 2
Intermittent or incorrect data.

Conditions for fault code:

• Abnormally large difference between two subsequent sensor
values. If the sensor value later stabilises to the new value,
the fault code will be deactivated. Note that if an inactive fault
code is present, the level sensors and sensor installation
should be checked. The control unit records a change in the
sensor values that is the equivalent of 10 cm

Possible cause:
• Level sensor arm damaged.
• Signal lead short-circuited to voltage.
• Break in the Ground lead.
• Faulty sensor.

Noticeable external symptoms:

• Warning lamp.
• The vehicle may lean abnormally.

Appropriate check:
• Check that the level sensor arm is intact, that the sensor is
installed correctly and that there is no play.
• “MID 150 SID 18 Level Sensor, Check” .
FMI 3
Abnormally high voltage or short circuit to higher voltage

Conditions for fault code:

• The control unit records a signal voltage from the level sen-
sor greater than 4.5 V.

13
Group 728 Possible cause:

Possible cause:
• Signal lead short-circuited to voltage.
• Break in the Ground lead.
• Faulty sensor.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 18 Level Sensor, Check”
FMI 4
Abnormally low voltage or short circuit to lower voltage

Conditions for fault code:

• The control unit records a signal voltage from the level sen-
sor that is below 0.5 V.

Possible cause:
• Signal lead short-circuited to Ground.
• Break in the supply cable.
• Faulty sensor.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 18 Level Sensor, Check”
FMI 7
Incorrect response from the mechanical system.

Conditions for fault code:

• Abnormally small change in sensor level value.
• The unfiltered sensor value usually fluctuates when driving
due to uneven road surfaces. If this fault code is set, then
there have been a large number of successive sensor values
that have shown a variation.

Possible cause:
• Level sensor arm damaged. • Faulty sensor.
• Signal lead short-circuited to voltage.
• Break in the Ground lead.
14
Group 728 Reaction from control unit:

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 18 Level Sensor, Check”

15
Group 728 7281–21–03–06

7281–21–03–06
MID 150 SID 18 Level Sensor, Check
Special tools and Equipment required
Tool Identification Tool Description
Number
9998533 Adapter for control unit, connector
X2 (22 pin)
88890039 Adapter, 4–pin DIN
9998699 Breakout Box (62–pin)
88890074 Multimeter
9813194 Adapter for control unit, connector
X1 (30–pin)

Note: Read off the other fault codes for the ECS system. If any
of the other solenoid valves also have an active fault code, the
fault is most likely located on one of the common cables, see
wiring diagram.
Check all the relevant connectors for bad contact, contact re-
sistance and oxidation. For a more detailed description of fault
tracing cables and connectors, see information in Group 3.

WARNING
Never disconnect the control arm for the level sensors with-
out first removing power from the vehicle. Personal injury
from electrical shock may occur.

Tests that can be carried out with the PC tool

The following tests are useful for a closer examination of the
solenoid valve function:

“7289–08–03–03 Level sensor, function test”

“7281–07–03–01 Level sensor, calibration”

Measurement at the component between the connector and the control unit
Note: If one of the values below is incorrect this could also have
caused the component to break down, in which case the com-
ponent must be checked.

Supply cable and signal voltage:

Conditions:
• Adapter 88890039 connected between level sensor and ca- Check that the power supply from the control unit reaches the
ble harness. level sensor.
Note: If the level sensor has been removed from the frame the Measure- Nominal Value
level sensors must be recalibrated according to “7281-07-03-01 ment points
Level sensor, calibration”.
1–2 U ≈ 3.5 -5.5 V
• Voltage measurement with multimeter 88890074.
Special Tools: 88890039, 88890074
• Starter key in drive position.
16
Group 728 Ground cable:

Check also that the signal voltage is sent from the level sensor.

Measure- Nominal Value

ment points
4–2 U ≈ 0.5 -4.5 V
Special Tools: 88890039, 88890074

Ground cable:
Conditions:
• Adapter 88890039 connected between solenoid valve pack-
age and cable harness.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
Measurement points Nominal Value
2 – Ground R — 0 ohms
Special Tools: 88890039, 88890074

Checking component
Note: Faults in the component may be caused by faults in the
cable harness for the control unit. Check the cable harness be-
fore connecting a new component.

Conditions:
• Adapter 88890039 connected on the component side but not
on the cable harness side.
• To disconnect the front level sensor connector, the sensor
must be removed from the frame.
Note: If the level sensor has been removed from the frame the
level sensors must be recalibrated according to “7281-07-03-01
Level sensor, calibration”.

• Resistance measurement with multimeter 88890074

• Starter key in stop position.
Measure- Nominal Value
ment points
4–2 R = 4.0 — 7.0 kohms
Special Tools: 88890039, 88890074

17
Group 728 Checking sub-systems

Checking sub-systems
Conditions:
• Breakout box 9998699 and adapter 9813194 connected be-
tween control unit connector X1 and the cable harness.
• Breakout box 9998699 and adapter 9998533 connected be-
tween control unit connector X2 and the cable harness.
Note: If the level sensor has been removed from the frame the
level sensors must be recalibrated according to “7281-07-03-01
Level sensor, calibration”.

• Voltage measurement with multimeter 88890074.

• Starter key in drive position.
SID Measure- Nominal Value
ment
points
18 X1:28 — U ≈ 0.5 -4.5 V
X1:11
18 X1:17 — U ≈ 3.5 -5.5 V
X1:11
18 X1:11 — U ≈ 0V
X2:22
Special Tools: 9998533, 9998699 x 2, 9813194, 88890074

Verification
To check that the fault is remedied use the tests in the PC tool
(see information in Group 7).

18
Group 728 MID 150 SID 24/26 Pressure Sensor

MID 150 SID 24/26 Pressure Sensor

General information
The pressure sensors provide information about the pressure in SID Component Number Component
the air bags to the control unit.
24 B 58 A Pressure sensor, Drive
Component: Axle
26 B 55 A Pressure sensor, extra
axle (Tag Axle)

Components:
B55A: Pressure Sensor, Tag Axle
B58A: Pressure Sensor, Drive Axle
A16: Control Unit, ECS

Fault code
FMI 2
Intermittent or incorrect data.

Conditions for fault code:

• The control unit records a difference between two consecu-
tive sensor values that exceeds 6 bar (87 psi).

Possible cause:
• Faulty sensor.
• Signal lead short-circuited to voltage.
• Break in the Ground lead.

Reaction from the control unit

• The system is set to the blocked mode..

Noticeable external symptoms:

• Warning lamp.
• The vehicle may lean abnormally.

Appropriate check:
• Check the cables, especially the Ground connection
• “MID 150 SID 24/26 Pressure Sensor, Check” .
FMI 3
Abnormally high voltage or short circuit to higher voltage

Conditions for fault code:

• The control unit records a signal voltage from the pressure
sensor greater than 4.8 V.

Possible cause:
• Signal lead short-circuited to voltage.
• Break in the Ground lead.
• Faulty sensor.
19
Group 728 Reaction from control unit:

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 24/26 Pressure Sensor, Check”
FMI 4
Abnormally low voltage or short circuit to lower voltage

Conditions for fault code:

• The control unit records a signal voltage from the level sen-
sor that is below 0.2 V.

Possible cause:
• Signal lead short-circuited to Ground.
• Open circuit in signal lead.
• Faulty sensor.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 24/26 Pressure Sensor, Check”
FMI 7
Incorrect response from the mechanical system.

Conditions for fault code:

• Abnormally small change in sensor level value.
• The unfiltered sensor value usually fluctuates when driving
due to uneven road surfaces. If this fault code is set, then
there have been a large number of successive sensor values
that have shown a variation.

Possible cause:
• Frozen air lines
• Signal lead short-circuited to voltage.
• Defective valve.
• Break in the Ground lead.
• Faulty sensor.

Reaction from control unit:

• The system is set to the blocked mode.
20
Group 728 Noticeable external symptoms:

Noticeable external symptoms:

• Warning lamp
• The vehicle may lean abnormally.

Appropriate check:
• “MID 150 SID 24/26 Pressure Sensor, Check”

21
Group 728 7281–21–03–08

7281–21–03–08
MID 150 SID 24/26 Pressure Sensor, Check
Special tools and Equipment required
Tool Identification Tool Description
Number
9998533 Adapter for control unit, connector
X2 (22 pin)
88890039 Adapter, 4–pin DIN
9998699 Breakout Box (62–pin); 2 required
88890074 Multimeter
9813194 Adapter for control unit, connector
X1 (30–pin)

Note: Read off the other fault codes for the ECS system. If any
of the other solenoid valves also have an active fault code, the
fault is most likely located on one of the common cables, see
wiring diagram.
Check all the relevant connectors for bad contact, contact re-
sistance and oxidation. For a more detailed description of fault
tracing cables and connectors, see information in Group 3.

Tests that can be carried out with the PC tool

The following tests are useful for a closer examination of the
drive axle pressure sensor function:

“Pressure sensor test”

Measurement at the component between the connector and the control unit
Note: If one of the values below is incorrect this could also have
caused the component to break down, in which case the com-
ponent must be checked.

Supply cable and signal voltage:

Conditions:
• Adapter 88890039 connected between pressure sensor and Measure- Nominal Value
cable harness. ment points
• Voltage measurement with multimeter 88890074. C—A U ≈ 0.2 -4.8 V
• Starter key in drive position.
Special Tools: 88890039, 88890074
Check that the power supply from the control unit reaches the
pressure sensor.

Measure- Nominal Value

ment points
B-A U ≈ 3.5 -5.5 V
Special Tools: 88890039, 88890074

Check also that the signal voltage is sent from the pressure
sensor.
22
Group 728 Ground cable:

Ground cable:
Conditions:
• Adapter 88890039 connected between pressure sensor and
cable harness.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
Measurement points Nominal Value
A– Ground R — 0 ohms
Special Tools: 88890039, 88890074

Checking component
Note: Faults in the component may be caused by faults in the
cable harness for the control unit. Check the cable harness be-
fore connecting a new component.

Conditions:
• Adapter 88890039 connected on the component side but not
on the cable harness side.
• Resistance measurement with multimeter 88890074.
• Starter key in stop position.
Measure- Nominal Value
ment points
C—A R = 30 — 60 K-ohms
Special Tools: 88890039, 88890074

Checking sub-systems
Conditions:
• Breakout box 9998699 and adapter 9813194 connected be- Signal voltage from the pressure sensor affects the pressure in
tween control unit connector X1 and the cable harness. the air bags it is connected to. The following values are approxi-
• Breakout box 9998699 and adapter 9998533 connected be- mate and should be seen as guide values.
tween control unit connector X2 and the cable harness.
Pressure Nominal value
• Voltage measurement with multimeter 88890074.
1 bar (15 psi) U ≈ 0.8 V
• Starter key in drive position.
3 bar (44 psi) U ≈ 1.5 V
SID Measure- Nominal Value
ment 5 bar (73 psi) U ≈ 2.2 V
points
7 bar (102 psi) U ≈ 2.8 V
24 X1:23 — U ≈ 0.2 -4.8 V
9 bar (131 psi) U ≈ 3.5 V
X1:07
26 X1:21 — U ≈ 0.2 -4.8 V 11 bar (160 psi) U≈V
X1:07 Special Tools: 9998533, 9998699 x 2, 9813194, 88890074
24/26 X1:30 — U ≈ 3.5 5.5 V
X1:07
24/26 X1:07 — U≈0V
X2.22
Special Tools: 9998533, 9998699 x 2, 9813194, 88890074

23
Group 728 Verification

Verification
To check that the fault is remedied use the tests in the PC tool
(see “Tests that can be carried out with the PC tool”) or “Fault
tracing, ECS, Function test”, see information in Group 7.

24
Group 728 MID 150 SID 231 SAE J1939 Control Link

MID 150 SID 231 SAE J1939 Control Link

General information
The SAE J1939 data link is used to communicate with other
control units and provide them with information on axle load,
etc.

For further information regarding the SAE J1939 Control link,

see information in Group 0.

Component: A16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 2
Intermittent or incorrect data.

Conditions for fault code:

• If the control unit cannot communicate on the SAE J1939 da-
ta link, the control unit will interpret it as a fault and set an
fault code.

Possible cause:
• Fault on SAE J1939 data link between ECS control unit and
other control units.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• Fault-trace the SAE J1939 data link, see information in
Group 3.

25
Group 728 MID 150 SID 240 Program Memory

MID 150 SID 240 Program Memory

General information
At start-up the control unit checks that the software is correct by
comparing the generated check sums.

Display text:

Component: A16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 13
Values outside calibration values.

Conditions for fault code:

• If the checksum in the control unit memory does not corre-
spond, the control unit interprets this as a fault and sets an
fault code.

Possible cause:
• Internal fault in the control unit.
• Incorrectly programmed control unit.

Reaction from the control unit

• The system does not function.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• Reprogram the ECS control unit.

26
Group 728 MID 150 SID 250 SAE J1708 Information Link

MID 150 SID 250 SAE J1708 Information Link

General information
The information link SAE J1708 is one of several data links in
the vehicle.
For further information regarding the SAE J1708 information
link, see information in Group 0.

If the fault disappears, all the functions will be reset automati-

cally and the fault code made inactive.

Component: A16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 2
Intermittent or incorrect data.

Conditions for fault code:

• Number of collisions too large or incorrect messages on the
information link.

Possible cause:
• Fault on SAE J1939 data link between ECS control unit and
other control units.
• Fault on the information link.
• EMC interference.
• Internal fault in the control unit.

Reaction from the control unit:

• Support function via 1939 link.
• Diagnosis not possible.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• See information in Group 3.

27
Group 728 MID 150 SID 253 Calibration Memory, EEPROM

MID 150 SID 253 Calibration Memory, EEPROM

General information
This fault code describes internal faults in EEPROM.

Component: A16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 2
Intermittent or incorrect data.

Conditions for fault code:

• If the internal checksum does not correspond, this is inter-
preted as a fault and an fault code is set.
• If a parameter value is outside the given limits, it is inter-
preted as a fault and an fault code is set.

Possible cause:
• Incorrectly programmed control unit

Reaction from the control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• Reprogram the ECS control unit.

FMI 13
Values outside calibration values.

Conditions for fault code:

• If the checksum in the control unit memory does not corre-
spond, the control unit interprets this as a fault and sets an
fault code.

Possible cause:
• Incorrectly programmed control unit.

Reaction from the control unit

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• Calibrate the level sensors.

28
Group 728 MID 150 PSID 1 Level Sensor Voltage Supply

MID 150 PSID 1 Level Sensor Voltage Supply

General information
The ECS control unit supplies power to all level sensors via one
output.

Component:: A 16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 3
Abnormally high voltage or short-circuit to higher voltage.

Conditions for fault code:

• The control unit records a supply voltage to the level sensors
exceeding 5.5V.

Possible cause:
• Supply cable short-circuited to voltage.

Noticeable external symptoms:

• Warning lamp.

Appropriate check:
• Check that the level sensor arm is intact, that the sensor is
installed correctly and that there is no play.
• “MID 150 SID 18 Level Sensor, Check” page 27.
Focus on measurements on the supply cable first.

FMI 4
Abnormally low voltage or short circuit to lower voltage

Conditions for fault code:

• The control unit records a signal voltage from the level sen-
sor that is below 3.5 V.

Possible cause:
• Supply lead short-circuited to Ground.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 SID 18 Level Sensor, Check”
Focus on measurements on the supply cable first.

29
Group 728 MID 150 PSID 2 Pressure Sensor Voltage Supply

MID 150 PSID 2 Pressure Sensor Voltage Supply

General information
The ECS control unit supplies power to all pressure sensors via
one output.

Component: A 16 Control unit, ECS (electronically controlled

suspension).

FMI 3
Abnormally high voltage or short circuit to higher voltage

Conditions for fault code:

• The control unit records a supply voltage from the pressure
sensors greater than 5.5 V.

Possible cause:
• Supply cable short-circuited to voltage.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 SID 24/26 Pressure Sensor, Check”
Focus on measurements on the supply cable first.

FMI 4
Abnormally low voltage or short circuit to lower voltage

Conditions for fault code:

• The control unit records a signal voltage from the level sen-
sor that is below 3.5 V.

Possible cause:
• Supply lead short-circuited to Ground.

Reaction from control unit:

• The system is set to the blocked mode.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 SID 24/26 Pressure Sensor, Check”
Focus on measurements on the supply cable first.

30
Group 728 MID 150 PSID 3 Air Suspension Manual Control Switch

MID 150 PSID 3 Air Suspension Manual Control Switch

General information
In the event of a fault in the bogie switch the control unit as-
sumes that the switch is still in the last selected position. If the
fault disappears, resetting is carried out automatically.

Component: S 11 D Switch, (On / Off) , S 113 D Switch, (Up /

Down).

Fault code
FMI 7
Incorrect response from the mechanical system.

Conditions for fault code:

• The control unit records that the switch is in two positions at
the same time.

Possible cause:
• Faulty bogie switch.
• Short circuit to Ground in the cable harness between the
control unit and dash switches.

Reaction from control unit:

• The system does not react if the switch position changes.

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• “MID 150 PSID 3 Bogie Switch, Check”

31
Group 728 7281–21–03–01

7281–21–03–01
MID 150 PSID 3 Bogie Switch, Check
Special tools and Equipment required
Tool Identification Tool Description
Number
9998533 Adapter for control unit, connector
X2 (22 pin)
9998699 Breakout Box (62–pin); 2 required
88890074 Multimeter
9813194 Adapter for control unit, connector
X1 (30–pin)

Note: Check all the relevant connectors for bad contact, con-
tact resistance and oxidation. For a more detailed description of
fault tracing cables and connectors, see information in Group 3.

Tests that can be carried out with the PC tool

The following tests are useful for a closer examination of the bo-
gie switch function:

“7281-08-03-04 Bogie switch, test”

Checking sub-systems
Check that only one position at a time is active.

Conditions:
• Breakout box 9998699 and adapter 9813194 connected be-
tween control unit connector X 1and the cable harness.
Note: The terminals are positioned in order between 1-30 on
the breakout box.

• Breakout box 9998699 and adapter 9998533 connected be-

tween control unit connector X2 and the cable harness
Note: The terminals are positioned in order between 31-52 on
the breakout box.

• Voltage measurement with multimeter 88890074.

• Starter key in drive position.
Measure- Function Nominal Value
ment
points
X2:18 Bogie lift U < 0.5V (active) U ≈ Ubat
-X2:22 (48 (inactive)
-52)
X2:19 Bogie U < 0.5V (active) U ≈ Ubat
-X2:22 (49 press (inactive)
-52)
Special Tools: 9998699 x 2 9813194, 9998533, 88890074

32
Group 728 Verification

Verification
To check that the fault is remedied use the test in the PC tool
(see “Tests that can be carried out with the PC tool”) or “Fault
tracing, ECS, Function test”, see information in Group 7.

33
Group 728 MID 150 PSID 8 Calibration Memory Load Indicator

MID 150 PSID 8 Calibration Memory Load Indicator

General information
This fault code describes internal faults in EEPROM.

Component: A16 Control unit, ECS (electronically controlled

suspension)

Fault code
FMI 13
Values outside calibration values.

Conditions for fault code:

• Load indicator incorrectly calibrated.
• Load indicator not calibrated.

Possible cause:
• Load indicator has never been calculated.
• Incorrectly calibrated.

Reaction from the control unit

• No values are sent to the instrument.

Noticeable external symptoms:

• Load indicator out of order.
• Warning lamp / information lamp.

Appropriate check:
• • Carry out “3669–22–03–01 Load indicator, programming of
parameters”.
• Carry out “3669–07–03–01 Load indicator, calibration”.

FMI 14
Unknown fault / special instructions.

Conditions for fault code:

• Calibration data invalid.

Possible cause:
• Incorrectly calibrated.

Reaction from the control unit

• No values are sent to the instrument.

Noticeable external symptoms:

• Load indicator out of order.
• Warning lamp.

34
Group 728 Appropriate check:

Appropriate check:
• • Carry out “3669–22–03–01 Load indicator, programming of
parameters”.
• Carry out “3669–07–03–01 Load indicator, calibration”.
• Change software.

35
Group 728 MID 150 PSID 200 J1939 Data link Interruption, Vehicle ECU

MID 150 PSID 200 J1939 Data link Interruption, Vehicle ECU
General information
The control units share important information on the SAE J1939
data link. If a control unit lacks information from another control
unit, this fault code will be used to point out the control unit that
is expected to send information on the SAE J1939 data link.

Fault code
FMI 9
Abnormal update rate..

Conditions for fault code:

• If the ECS control unit does not receive the message from
the engine control unit via the SAE J1939 data link, the ECS
control unit interprets this as a fault and sets an fault code.

Possible cause:
• Open circuit in the SAE J1939 data link between the ECS
control unit and the engine control unit (ECU).

Reaction from control unit:

• Warning lamp
• Information is sent on the information link SAE J1708.
• Functionality will be limited if there are no signals present on
the information link J1708

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• Trouble shoot the SAE J1939 data link, see information in
Group 3.

36
Group 728 MID 150 PSID 201 J1939 Data link Interruption, Vehicle ECU

MID 150 PSID 201 J1939 Data link Interruption, Vehicle ECU
General information
The control units share important information on the SAE J1939
data link. If a control unit lacks information from another control
unit, this fault code will be used to point out the control unit that
is expected to send information on the SAE J1939 data link.

Fault code
FMI 9
Abnormal update rate..

Conditions for fault code:

• If the ECS control unit does not receive the message from
the engine control unit via the SAE J1939 data link, the ECS
control unit interprets this as a fault and sets an fault code.

Possible cause:
• Open circuit in the SAE J1939 data link between the ECS
control unit and the engine control unit (ECU).

Reaction from control unit:

• Warning lamp
• Information is sent on the information link SAE J1708.
• Functionality will be limited if there are no signals present on
the information link J1708

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• Trouble shoot the SAE J1939 data link, see information in
Group 3.

37
Group 728 MID 150 PSID 202 J1939 Data link Interruption, Vehicle ECU

MID 150 PSID 202 J1939 Data link Interruption, Vehicle ECU
General information
The control units share important information on the SAE J1939
data link. If a control unit lacks information from another control
unit, this fault code will be used to point out the control unit that
is expected to send information on the SAE J1939 data link.

Fault code
FMI 9
Abnormal update rate..

Conditions for fault code:

• If the ECS control unit does not receive the message from
the engine control unit via the SAE J1939 data link, the ECS
control unit interprets this as a fault and sets an fault code.

Possible cause:
• Open circuit in the SAE J1939 data link between the ECS
control unit and the engine control unit (ECU).

Reaction from control unit:

• Warning lamp
• Information is sent on the information link SAE J1708.
• Functionality will be limited if there are no signals present on
the information link J1708

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• Trouble shoot the SAE J1939 data link, see information in
Group 3.

38
 MID 150 PSID 204 J1939 Data Link Abnormal Update Rate,
Group 728
MID 136 ABS ECU

MID 150 PSID 204 J1939 Data Link Abnormal Update Rate,
MID 136 ABS ECU
General information
The control units share important information on the SAE J1939
data link. If an abnormal update rate is detected on the J1939
MID 136 data link, a fault code will be set. The criteria is one (1)
message missing for 1 second (10 times the update rate).

Fault code
FMI 9
Abnormal update rate..

Conditions for fault code:

• If the ECS control unit does not receive a timely update mes-
sage from the engine control unit via the SAE J1939 data
link, the ECS control unit interprets this as a fault and sets
an fault code.

Possible cause:
• Open circuit in the SAE J1939 data link between the ECS
control unit and the engine control unit (ECU).

Reaction from control unit:

• Warning lamp
• Information is sent on the information link SAE J1708.
• Functionality will be limited if there are no signals present on
the information link J1708

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• Trouble shoot the SAE J1939 data link, see information in
Group 3.

39
 MID 150 PSID 210 J1939 Data link Interruption, Control unit
Group 728
External Lighting

MID 150 PSID 210 J1939 Data link Interruption, Control unit
External Lighting
General information
The control units share important information on the SAE J1939
data link. If a control unit lacks information from another control
unit, this fault code will be used to point out the control unit that
is expected to send information on the SAE J1939 data link.

Fault code
FMI 9
Abnormal update rate..

Conditions for fault code:

• If the ECS control unit does not receive the message from
the engine control unit via the SAE J1939 data link, the ECS
control unit interprets this as a fault and sets an fault code.

Possible cause:
• Open circuit in the SAE J1939 data link between the ECS
control unit and the engine control unit (ECU).

Reaction from control unit:

• Warning lamp
• Information is sent on the information link SAE J1708.
• Functionality will be limited if there are no signals present on
the information link J1708

Noticeable external symptoms:

• Warning lamp

Appropriate check:
• Trouble shoot the SAE J1939 data link, see information in
Group 3.

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Group 728 Operation Numbers

Operation Numbers
OPID Number Identifier Page
7281–21–03–03 MID 150 SID 4/7 Solenoid Valve Assembly Drive Axle, Check 5

7281–21–03–04 MID 150 SID 5/8 Solenoid Valve Assembly Extra Axle, Check 10
7281–21–03–06 MID 150 SID 18 Level Sensor, Check 16
7281–21–03–08 MID 150 SID 24/26 Pressure Sensor, Check 22
7281–21–03–01 MID 150 PSID 3 Bogie Switch, Check 32

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