P2037

No or incorrect CAN message from control unit N15/3 (ETC [EGS] control unit) (P0600)

Test 1: Check CAN bus.

1. Check CAN bus.

Test 1.1: Check CAN bus. ( General test information )

Test 1.2: Voltage supply of engine compartment CAN control modules

Test 1.3: Resistance test of engine compartment CAN

Test 1.4: Information to engine compartment CAN network

Test 1.5: Test with the aid of the measuring system

1.1. Check CAN bus. ( General test information )
If several fault codes regarding CAN communication have occurred, the following causes of the fault are likely

- Open circuit in voltage supply to the control modules involved
- Short circuit or open circuit of CAN wires
- Connector sleeves of the CAN bus
If CAN communication between control module ME motor electronics and at least one other control module is fault-free, there is no fault at the CAN element of the control module ME motor electronics.In this case proceed as follows:

- Read fault memory of control module to which there is a fault in the communication.If a CAN fault regarding communication with control module ME motor electronics is present in this control module, then first of all test CAN lines between the two control modules.
Continue with button F2

1.1. No further information available.


1.2. Voltage supply of engine compartment CAN control modules

Test 1.2.1: EZS - Electronic ignition switch

Test 1.2.2: ICM - Instrument cluster with maintenance interval display

Test 1.2.3: SCM [MRM] - Steering column module

Test 1.2.4: ETC - Electronic transmission control

Test 1.2.5: ESM - Electronic selector module

Test 1.2.6: HRA - Headlamp range adjustment

Test 1.2.7: ME-SFI 2.7 - Motor electronics 2.7

Test 1.2.8: ESP - Electronic stability program

Test 1.2.9: AIRmatic

Test 1.2.10: DTR - Distronic

Test 1.2.11: RevETR-LF - Left front reversible emergency tensioning retractor

Test 1.2.12: RevETR-RF - Right front reversible emergency tensioning retractor

1.2.1. EZS - Electronic ignition switch
Warning!Communication with ECU required.


1.2.2. ICM - Instrument cluster with maintenance interval display
Warning!Communication with ECU required.


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


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


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


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


1.2.7. ME-SFI 2.7 - Motor electronics 2.7
Warning!Communication with ECU required.


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


1.2.9. AIRmatic
Warning!Communication with ECU required.


1.2.10. DTR - Distronic
Warning!Communication with ECU required.


1.2.11. RevETR-LF - Left front reversible emergency tensioning retractor
Warning!Communication with ECU required.


1.2.12. RevETR-RF - Right front reversible emergency tensioning retractor
Warning!Communication with ECU required.


1.3. Resistance test of engine compartment CAN

Test 1.3.1: CAN bus to control unit ME-SFI 2.7

1.3.1. CAN bus to control unit ME-SFI 2.7

Test 1.3.1.1: Test total resistance of engine compartment CAN.

Test 1.3.1.2: Test terminating resistor of CAN element in control module EZS.

Test 1.3.1.3: Test terminating resistor of CAN element in control module ME-SFI 2.7.

1.3.1.1. Test total resistance of engine compartment CAN.
Test prerequisite

- Fault code 'P207D' present
Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- Measure resistance with multimeter between sockets (4.11) 96 and (4.1) 86 of the 126-pole socket box tester.
Specified value

- Resistor[55...65]ohms
Question

- Is the measurement value OK?


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

- Fault in control unit EZS: Read out fault memory of control unit N73 (EIS [EZS] control unit).


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

- Line from component N73 (EIS [EZS] control unit) to component N3/10 (ME-SFI [ME] control unit)
- Test terminating resistor of CAN element in control module EZS.


1.3.1.2. Test terminating resistor of CAN element in control module EZS.
Test terminating resistor of CAN element in control module EZS.
Test prerequisite

- Fault code 'P207D' present
Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- Disconnect coupling 4 at component N3/10 (ME-SFI [ME] control unit).
- Measure resistance with multimeter between sockets (4.11) 96 and (4.1) 86 of the 126-pole socket box tester.
Specified value

- Resistor[115...125]ohms
Question

- Is the measurement value OK?


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

- Fault in control unit EZS: Read out fault memory of control unit N73 (EIS [EZS] control unit).
- Test terminating resistor of CAN element in control module ME-SFI 2.7.


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

- Line from component N73 (EIS [EZS] control unit) to component N3/10 (ME-SFI [ME] control unit)
- N73 (EIS [EZS] control unit)
End of test

1.3.1.3. Test terminating resistor of CAN element in control module ME-SFI 2.7.
Test prerequisite

- Fault code 'P207D' present
Test sequence

- Switch off ignition.
- Connect socket box (126-pin) to component N3/10 (ME-SFI [ME] control unit).
- Connector 4 is plugged in at control unit.
- Unplug the socket 4 from the wiring harness at the socket box.
- Measure resistance with multimeter between sockets (4.11) 96 and (4.1) 86 of the 126-pole socket box tester.
Specified value

- Resistor[115...125]ohms
Question

- Is the measurement value OK?


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

- Fault in control unit EZS: Read out fault memory of control unit N73 (EIS [EZS] control unit).
End of test

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

- N3/10 (ME-SFI [ME] control unit)
End of test

1.4. Information to engine compartment CAN network

Test 1.4.1: Arrangement diagramNOTESome of the control units listed are special equipment and not installed in every vehicle.

Test 1.4.2: Wiring diagram of CAN bus

1.4.1. Arrangement diagramNOTESome of the control units listed are special equipment and not installed in every vehicle.
Location diagram (with special equipment)
Figure legend

- A1 (Instrument cluster)
- A76 (Left front reversible emergency tensioning retractor)
- A76/1 (Right front reversible emergency tensioning retractor)
- N3/9 (CDI control unit)
- N3/10 (ME-SFI [ME] control unit)
- N15/3 (ETC [EGS] control unit)
- N15/5 (Electronic selector lever module control unit)
- N47-5 (ESP, SPS [PML] and BAS control unit)
- N51 (AIRmatic with ADS control module)
- N51/2 (ABC control module)
- N63/1 (DTR control module)
- N71 (Headlamp range adjustment control module)
- N73 (EIS [EZS] control unit)
- N80 (Steering column module)
- Communication with ECU required







1.4.2. Wiring diagram of CAN bus
Note

- WIS is not available on this system.
- It is not possible to display the requested WIS document [ pe0019p2200sa ].
- You can start WIS on another system and display the WIS document by entering the document number [ pe0019p2200sa ] in the 'Contents' field.


1.4.2. No further information available.


1.5. Test with the aid of the measuring system
Test sequence

- Measurement of level voltage of engine CAN buses CAN bus High and CAN bus Low with the universal oscilloscope
- Disconnect one of the devices from the engine CAN bus.
- Observe level voltage.
- Reconnect the disconnected device to the engine CAN bus.
- Repeat this procedure for all CAN users.
Specified value

- As soon as the faulty branch was disconnected, the current image of the level voltage changes.
Possible cause of fault in the faulty branch

- Check CAN solder connections in wiring harness.
- Test connectors and wiring for CAN of engine compartment CAN control modules.
- Control unit
Communication with ECU required ( Measuring system )