Communication Problems With the Differential Electronic Module (DEM)

Communication problems with the differential electronic module (DEM)

Checking the diagnostic trouble codes (DTCs)
If diagnostic trouble codes (DTCs) for All-wheel drive (AWD) are stored in the differential electronic module (DEM) or in the central electronic module (CEM), these must be fault traced first.

Were diagnostic trouble codes (DTCs) stored in the differential electronic module (DEM) or in the central electronic module (CEM)?

Yes - DONE

No - Checking the wiring and terminals

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Checking the wiring and terminals




- Ignition off.
Check the differential electronic module (DEM) connector. Check for damaged or bent terminal pins. Check for contact resistance. Check for oxidation.
Check the wiring for CAN communication between the differential electronic module (DEM) connector and the 64/5D junction point. Check for an open-circuit.
Remedy as necessary.

Other information
- Connecting the breakout box, B5254T7 Connecting the Breakout Box, Brake Control Module (BCM)
- Checking wiring and terminals Checking Wiring and Terminals









Continue - Verification

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Verification




Verification

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








- Ignition off
- Reconnect the connectors, components, etc.
- Test drive the car according to: 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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VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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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 - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking the diagnostic trouble codes (DTCs)

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