Part 1

No or incorrect CAN message from control unit N73 (EIS [EZS] control unit)

Test 1: Engine compartment CAN test

1. Engine compartment CAN test

Test 1.1: Check CAN bus.

1.1. Check CAN bus.

Test 1.1.1: Read fault memories of all engine compartment CAN control modules and delete if necessary. - Quick test

Test 1.1.2: Engine compartment CAN test

1.1.1. Read fault memories of all engine compartment CAN control modules and delete if necessary. - Quick test
Engine compartment CAN test
Note

- Before the CAN test it is good practice to erase the fault memory of all the control modules connected to the engine compartment CAN in order to remove any sporadic faults or faults which are no longer current.
Test prerequisites

- Ignition has been switched on for at least 10 s.
Test sequence

- Perform quick test or continue with key F4.
- Test of voltage supply of the engine compartment CAN control modules.
- Test connectors and wiring for CAN of engine compartment CAN control modules.
Question

- Do you wish to perform the quick test?

YES
Warning!Communication with ECU required.

NO

Test 1.1.1.1: Voltage supply of engine compartment CAN control modules

Test 1.1.1.2: Resistance test of engine compartment CAN

Test 1.1.1.3: Check CAN bus. ( General test information )

1.1.1.1. Voltage supply of engine compartment CAN control modules

Test 1.1.1.1.1: EZS - Electronic ignition switch

Test 1.1.1.1.2: IC - Instrument cluster

Test 1.1.1.1.3: SCM [MRM] - Steering column module

Test 1.1.1.1.4: ETC - Electronic transmission control

Test 1.1.1.1.5: ESM - Electronic selector module

Test 1.1.1.1.6: ME-SFI 2.7.1 - Motor electronics 2.7.1

Test 1.1.1.1.7: ESP - Electronic stability program

Test 1.1.1.1.8: DTR - Distronic

Test 1.1.1.1.9: AIRmatic

Test 1.1.1.1.10: SBC

Test 1.1.1.1.11: SGR - Radar sensors control unit

Test 1.1.1.1.12: TPC - Tire pressure monitor

Test 1.1.1.1.13: N118 (Fuel pump control module)

Test 1.1.1.1.14: HRA - Headlamp range adjustment

1.1.1.1.1. EZS - Electronic ignition switch
Test prerequisite

- Battery voltage is OK.
- The fuses are OK.
Status of relevant actual value:
- Power supply:Warning! Communication with ECU required.
Specified value:

- Power supply [11.0...14.5] V
Question

- Is the actual value o.k.?

YES
The actual value is okay.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
- Check alternator.
End of test

NO
The actual value is not o.k.Test sequence

- Switch off ignition.
- Detach sockets A and C at component N73 (EIS [EZS] control unit).
- Measure direct voltage with multimeter between sockets (N73) B.2 and (N73) C.1
Specified value:

- Voltage [11.0...14.5] V
Question

- Are the measurement values OK?

YES
The measurement values are OK.Possible cause and remedy

- Inspect connector B,C at control unit N73 (EIS [EZS] control unit) for damage, correct connection, loose contact and corrosion and repair, if necessary.
- N73 (EIS [EZS] control unit)
End of test

NO
The measurement values are not OK.Possible cause and remedy

- Line between component N73 (EIS [EZS] control unit) and component N10/1 (Driver-side SAM control unit with fuse and relay module)
- Line between component N73 (EIS [EZS] control unit) and component Z6 (Ground connector sleeve)
- N10/1 (Driver-side SAM control unit with fuse and relay module)
- Z6 (Ground connector sleeve)
End of test

1.1.1.1.2. IC - Instrument cluster
Test prerequisites

- Fuse N10/1f64 (Fuse 64) is OK.
Test sequence

- Switch off ignition.
- Detach coupling at component A1 (Instrument cluster).
- Measure direct voltage with multimeter between sockets (A1) 1 and (A1) 6
- Switch on ignition.
Specified value

- Voltage [11.0...14.5] V
Question:Is the measurement value OK?

YES
The measurement value is OK.Possible cause and remedy

- A1 (Instrument cluster)
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Line between component A1 (Instrument cluster) and component N10/1 (Driver-side SAM control unit with fuse and relay module)
- Lines between A1 (Instrument cluster) and W15/2 (Ground, left footwell)
End of test

1.1.1.1.3. SCM [MRM] - Steering column module
Warning!Communication with ECU required.

1.1.1.1.4. ETC - Electronic transmission control
Warning!Communication with ECU required.

1.1.1.1.5. ESM - Electronic selector module
Warning!Communication with ECU required.

1.1.1.1.6. ME-SFI 2.7.1 - Motor electronics 2.7.1
Warning!Communication with ECU required.

1.1.1.1.7. ESP - Electronic stability program
Warning!Communication with ECU required.

1.1.1.1.8. DTR - Distronic

Test 1.1.1.1.8.1: Check power supply of component N63/1 (DTR control module).

Test 1.1.1.1.8.2: Check power supply of component A89 (DTR controller unit).

1.1.1.1.8.1. Check power supply of component N63/1 (DTR control module).
Check power supply at control unit N63/1 (DTR control module).
Test sequence

- Switch off ignition.
- Disconnect coupling 2 at component N63/1 (DTR control module).
- Measure direct voltage with multimeter between sockets (N63/1) 2.8 and (N63/1) 2.4
- Switch on ignition.
Specified value

- [11.0 ... 14.5] V
Question

- Is the value o.k.?

YES
Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measured value is not within the specified value range.Possible cause and remedy

- Cables between component N10/1 (Driver-side SAM control unit with fuse and relay module) and control module A89 (DTR controller unit)

1.1.1.1.9. AIRmatic

Test 1.1.1.1.9.1: Test voltage of terminal 30 at control unit N51 (AIRmatic with ADS control module).

Test 1.1.1.1.9.2: Test of cable for voltage supply

Test 1.1.1.1.9.3: Test procedure ground cable

1.1.1.1.9.1. Test voltage of terminal 30 at control unit N51 (AIRmatic with ADS control module).
Test prerequisite

- Battery voltage is OK.
Status of the relevant actual values:
- Terminal 30:Warning! Communication with ECU required.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between sockets (2.21) 55 and (2.47) 81 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The actual value is not o.k.Note

- This test did not produce any clear result.
- Select further tests.

1.1.1.1.9.2. Test of cable for voltage supply
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between ground and socket (2.47) 81 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component N51 (AIRmatic with ADS control module)
- F34f37 (Fuse 37)
End of test

1.1.1.1.9.3. Test procedure ground cable
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.

- W15/Measure resistance with multimeter between 1 and (2.21) 55 of the 35-pole socket box tester.
Specified value

- [<1ohms ]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Ground cable
- W15/1 (Ground (right footwell))
End of test

1.1.1.1.10. SBC

Test 1.1.1.1.10.1: Check power supply of component Right SBC.

Test 1.1.1.1.10.2: Check power supply of component Left SBC.

1.1.1.1.10.1. Check power supply of component Right SBC.

Test 1.1.1.1.10.1.1: Test voltage of terminal 87 at control unit A7/4n1 (SBC right control module).

Test 1.1.1.1.10.1.2: Test of cable for voltage supply

Test 1.1.1.1.10.1.3: Test procedure ground cable

1.1.1.1.10.1.1. Test voltage of terminal 87 at control unit A7/4n1 (SBC right control module).
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between sockets (1.44) 44 and (1.42) 42 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component A7/4n1 (SBC right control module)
- N10/1f47 (Fuse 47)
End of test

1.1.1.1.10.1.2. Test of cable for voltage supply
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between ground and socket (1.42) 42 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component A7/4n1 (SBC right control module)
- N10/1f47 (Fuse 47)
End of test

1.1.1.1.10.1.3. Test procedure ground cable
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.

- W14/Measure resistance with multimeter between 2 and (1.44) 44 of the 35-pole socket box tester.
Specified value

- [<1ohms ]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Ground cable
- W14/2 (Left SBC ground)
End of test

1.1.1.1.10.2. Check power supply of component Left SBC.

Test 1.1.1.1.10.2.1: Test voltage of terminal 87 at control unit A7/3 (SBC left hydraulic unit).

Test 1.1.1.1.10.2.2: Test of cable for voltage supply

Test 1.1.1.1.10.2.3: Test procedure ground cable

1.1.1.1.10.2.1. Test voltage of terminal 87 at control unit A7/3 (SBC left hydraulic unit).
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between sockets (1.44) 44 and (1.42) 42 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component A7/3n1 (SBC left control module)
- N10/1f47 (Fuse 47)
End of test

1.1.1.1.10.2.2. Test of cable for voltage supply
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.
- Switch on ignition.

- Measure direct voltage with multimeter between ground and socket (1.42) 42 of the 126-pole socket box tester.
Specified value

- [11...14 V]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Lines to component A7/3 (SBC left hydraulic unit)
- N10/1f47 (Fuse 47)
End of test

1.1.1.1.10.2.3. Test procedure ground cable
Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Connect socket box.

- W14/Measure resistance with multimeter between 2 and (1.44) 44 of the 35-pole socket box tester.
Specified value

- [<1ohms ]
Question

- Is the measurement value OK?

YES
The measurement value is OK.Note

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Ground cable
- W14/2 (Left SBC ground)
End of test

1.1.1.1.11. SGR - Radar sensors control unit
Test voltage supply of circuit 87.
Test prerequisite

- Battery voltage is OK.
- Fuse N10/1f46 (Fuse 46) in component N10/1 (Driver-side SAM control unit with fuse and relay module) is o.k.
Status of relevant actual value:
- Voltage supply terminal 15:Warning! Communication with ECU required.
Test sequence

- Switch off ignition.
- Separate plug connection A at control unit N62/1 (Radar sensors control unit (SGR)).
- Measure direct voltage with multimeter between sockets (N62/1) A.16 and (N62/1) A.1
Specified value

- Voltage[11.0 ... 14.5] V
Question

- Is the measurement value OK?

YES
Test voltage supply of circuit 87.
Test prerequisite

- Fuse N10/1f46 (Fuse 46) in component N10/1 (Driver-side SAM control unit with fuse and relay module) is o.k.
Status of relevant actual value:
- Voltage supply terminal 15:Warning! Communication with ECU required.
Test sequence

- Switch on ignition.
- Measure direct voltage with multimeter between sockets (N62/1) A.16 and (N62/1) A.5
Specified value

- Voltage[11.0 ... 14.5] V
Question

- Is the measurement value OK?

YES
The measurement value is OK.Possible cause and remedy

- In the event of stored faults with a high fault frequency count or in the event of customer complaints, check lines and connectors for loose contact and corrosion..
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Check line from N62/1 (Radar sensors control unit (SGR)) to N10/1 (Driver-side SAM control unit with fuse and relay module) for Short circuit or open circuit.
- Check line from N62/1 (Radar sensors control unit (SGR)) to W15/2 (Ground, left footwell) for Open circuit.
- Check control unit N10/1 (Driver-side SAM control unit with fuse and relay module).
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Check line from N62/1 (Radar sensors control unit (SGR)) to N10/1 (Driver-side SAM control unit with fuse and relay module) for Short circuit or open circuit.
- Check line from N62/1 (Radar sensors control unit (SGR)) to W15/2 (Ground, left footwell) for Open circuit.
- Check control unit N10/1 (Driver-side SAM control unit with fuse and relay module).
End of test

1.1.1.1.12. TPC - Tire pressure monitor
Operation number of operation texts and work units or standard texts and flat rates:40-0641Test prerequisite

- Battery voltage is OK.
Test sequence

- Switch off ignition.
- Disconnect connector at component N88 (TPM [RDK] control unit).
- [A.16] Measure direct voltage with multimeter between 16 and 15 [A.15]
Specified value

- Voltage[11.0...14.5] V
Question

- Is the measurement value OK?

YES
The measurement value is OK.Possible cause and remedy

- Inspect cables, electrical connections and plug connections for damage, correct connection, loose contact and corrosion, and repair or replace if necessary.
- Replace component N88 (TPM [RDK] control unit).
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Check fuse f2 (voltage supply from control unit N88 (TPM [RDK] control unit)) in component N10/3 (SAM control module with fuse and relay module rear-end 1).
- Check lines from component N88 (TPM [RDK] control unit) to component N10/3 (SAM control module with fuse and relay module rear-end 1).
End of test

1.1.1.1.13. N118 (Fuel pump control module)

Test 1.1.1.1.13.1: Check power supply at control unit N118 (Fuel pump control module).

1.1.1.1.13.1. Check power supply at control unit N118 (Fuel pump control module).
Possible cause and remedy

- Test fuse, replace if necessary
-
Question

- Is fuse OK?

YES
Test prerequisite

- If other control units also report low-voltage faults, check alternator and governor, repair or replace as necessary.
-
Test sequence

- Switch on ignition.
- Unplug 4-pin connector from component N118 (Fuel pump control module).
- Measure voltage at the unclipped cable.(Ground- Positive)
- Measure direct voltage with multimeter between sockets (N118) 1.2 and (N118) 1.1
Specified values

- Voltage: [11.0 ... 14.5] V
Question

- Is the measurement value OK?

YES
The measurement value is OK.Further possible causes of fault

- Inspect plug connections for corrosion, pinched insulation and loose contact.
End of test

NO
The measurement value is not OK.Possible cause and remedy

- Inspect lead of voltage supply to control module N118 (Fuel pump control module) if necessary for loose contact, damage and corrosion and repair.
End of test

NO
Replace faulty fuse.End of test

1.1.1.1.14. HRA - Headlamp range adjustment
Warning!Communication with ECU required.