Communication Fault

Communication fault

Checking the component and wiring
The diagnostic trouble code (DTC) indicates that communication between the central electronic module (CEM) and the wiper motor module (WMM), rain sensor module (RSM) (accessory), is not functioning. This may be due to a fault in the cable between the control modules or a defective communication device in one or both of the control modules.
Check the cable between the central electronic module (CEM) and the wiper motor module (WMM). Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) connector terminal #G3 (#3) and wiper motor module (WMM) terminal #1.
Also check that the fuse for the windshield wipers is intact. Replace the fuse if necessary.
Check the cable between the central electronic module (CEM) and the rain sensor module (RSM). Check for an open-circuit. Check for a short-circuit to ground.
Take readings between:
- Central electronic module (CEM) connector terminal #H23 (#37) and rain sensor module (RSM) terminal #3.
Also check that the fuse for the rain sensor is intact. Replace the fuse if necessary.

Other information
- Connecting the breakout box Connecting the Breakout Box, Central Electronic Module (CEM)
- Signal specification Signal Description, Central Electronic Module (CEM)
- Location of components Component Location, Central Electronic Module (CEM)
- Control module relay box passenger compartment Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals













Was a fault detected?

Yes - Verification

No - Replacing the control module

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Replacing the control module
Try replacing the wiper motor module (WMM).

Other information
- Wiper mechanism, windshield Service and Repair

Continue - Verification

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Verification




Verification

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








- Ignition off
- Reinstall the connectors, components etc.
- Ignition on.
Activate the windshield wipers in the intermittent wiping position.
Activate the windshield wipers in the low speed position.
Activate the windshield wipers in the high speed position.
Check the function. See: Rain sensor, check Testing and Inspection
Check that the function is OK.

Is the function OK?

Yes - Troubleshooting procedure complete

No - 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 component and wiring

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