Communication Problems With the Differential Electronic Module (DEM)

Communication problems with the differential electronic module (DEM)

Checking diagnostic trouble codes (DTCs) in the central electronic module




Checking diagnostic trouble codes (DTCs) in the central electronic module

Checking other diagnostic trouble codes (DTCs)
In the event of communication problems, the fault may exist in other parts of the communications network.
The role of the central electronic module is to generally control the communications network and to store diagnostic trouble codes (DTCs) in the event of communication problems between control modules.
If there are diagnostic trouble codes (DTCs) stored for communication problems in the central electronic module, stop the fault tracing and fault trace the central electronic module.

Were diagnostic trouble codes (DTCs) for communication problems stored in the central electronic module?

Yes - DONE

No - No Fault Found

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DONE - DONE

No Fault Found - Checking diagnostic trouble codes (DTCs)

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Checking diagnostic trouble codes (DTCs)




- Ignition on
- Wait approximately 60 seconds
- Read off the status of the diagnostic trouble code (DTC).





Is the status of the diagnostic trouble code (DTC) permanent?

Yes - Checking wiring and terminals

No - Intermittent fault

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Checking wiring and terminals




- Ignition off.
Check the connector to the brake control module (BCM). Check for damaged or bent pins as well as contact resistance and oxidation.
Check the cable between Brake control module (BCM)terminal #11 (#A11) and Differential electronic module (DEM) terminal #7. Check for an open-circuit and short-circuit to ground or voltage.
Check the cable between Brake control module (BCM)terminal #15 (#A15) and Differential electronic module (DEM) terminal #8. Check for an open-circuit and short-circuit to ground or voltage.
Check that the wiring is not too close to a source of interference such as a carphone etc.
Remedy as necessary.

Other information
- To connect the breakout box, see Connecting the breakout box, brake control module (BCM) Connecting the Breakout Box, Brake Control Module (BCM)
- Checking wiring and terminals Checking Wiring And Terminals.










Continue - Verification

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

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Attempt New Test - Checking diagnostic trouble codes (DTCs) in the central electronic module

FAULT-TRACING FAILED - FAULT-TRACING FAILED

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Verification




Verification

Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Test drive the car. See Test Drive Form (DSTC (dynamic stability and traction control) /brake control module), description Test Drive Form (DSTC (Dynamic Stability And Traction Control) /Brake Control Module), Description
- Ignition on.
Read off the status of the diagnostic trouble code (DTC).





Is the status of the diagnostic trouble code (DTC) intermittent?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - Fault Found

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Intermittent fault

Hint: The status of the diagnostic trouble code (DTC) indicates that the brake control module has previously registered a fault but that the fault is not active.

Check the connectors of the brake control module (BCM) and the differential electronic module (DEM) for contact resistance and oxidation.
Also check that the wiring for CAN communication is not too close to a source of interference such as a carphone etc.
Remedy as necessary.

Other information
- To connect the breakout box, see: Connecting the breakout box, brake control module (BCM) Connecting the Breakout Box, Brake Control Module (BCM)
- Checking wiring and terminals Checking Wiring And Terminals.










Continue - DONE

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Fault-tracing information




Information

Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

Do you want to view the information again?

Yes - Attempt New Test

No - Fault Found

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Attempt New Test - Checking diagnostic trouble codes (DTCs) in the central electronic module

FAULT-TRACING FAILED - Fault Found

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