Communication Fault

Communication fault

Checking components and wiring








- Switch off the ignition. Wait 10 seconds
- Disconnect the connectors from the supplemental restraint system module (SRS)
- Disconnect connector F from the central electronic module (CEM).

Caution! Do not touch the terminal pins in the supplemental restraint system module (SRS), the central electronic module (CEM) and the phone module (PHM). There is a risk of static discharge. This could damage the supplemental restraint system module (SRS), the central electronic module (CEM) and the phone module (PHM).

Check the connectors to the supplemental restraint system module (SRS) and the central electronic module (CEM). Check for damage to pins and terminals in the connectors. Check for contact resistance in the connectors.
Remedy as necessary.
Check the cable between the supplemental restraint system module (SRS) and the central electronic module (CEM). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable between:
- Supplemental restraint system module (SRS) terminal #A26 and central electronic module (CEM) terminal F#12 (#12).
Remedy as necessary.
- Disconnect connector A from the central electronic module (CEM).
Check connector A from the central electronic module (CEM). Check for damage to pins and terminals in the connectors. Check for contact resistance in the connector.
Remedy as necessary.
Check the internal cable in the central electronic module (CEM). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable between:
- Central electronic module (CEM) terminals F#12 (#12) and A#33 (#33).
Remedy as necessary.
- Disconnect connector A from the phone module (PHM).
Check connector A from the phone module (PHM). Check for damage to pins and terminals in the connectors. Check for contact resistance in the connector.
Remedy as necessary.
Check the cable between the central electronic module (CEM) and the phone module (PHM). Check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Check the cable between:
- Central electronic module (CEM) terminals A#33 (#33) and phone module (PHM) terminals #A17.
Remedy as necessary.
If no fault is found, continue fault-tracing from the central electronic module (CEM) and the phone module (PHM).

Other information
- Connecting the breakout box Connecting the Breakout Box, Supplemental Restraint System Module (SRS)
- Signal specification Signal Specification
- For further information about cable routing and terminals, see the wiring diagram
- To access or replace the supplemental restraint system module (SRS) and the connectors. See: Air bag supplemental restraint system Service and Repair
- To access or replace the central electronic module (CEM) and the connectors, see: Control module relay box passenger compartment Service and Repair
- To access or replace the phone module (PHM) and the connectors, see: Phone Module (PHM) Phone Module (PHM)
- For information about the repair of SRS wiring, see: Wiring harness supplemental restraint system (SRS) Wiring Harness Supplemental Restraint System (SRS)
- 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.




- Switch off the ignition. Wait 10 seconds
- Disconnect the battery negative lead
- Reinstall the connectors, components etc.
- Ignition on
- Connect the battery negative lead. Wait 10 seconds.

Warning! There must not be anyone inside the passenger compartment when the battery is connected.

Read diagnostic trouble codes by clicking the VCT2000 symbol.
If the fault is intermittent, the fault has been remedied.





Is the fault 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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FAULT-TRACING FAILED - No Fault Found

Attempt New Test - Checking components and wiring

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