Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CEM-U042387

Condition
The control modules communicate with each other for exchange of information in a network via a standardized serial communication procedure - CAN (Controller Area Network).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- No communication with the Driver information module (DIM).
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Ignition switch position I and II.
- Interior lighting relay is activated.

Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.

Substitute value
- The function switches off permanently after 100 operating cycles where the fault was detected. Erasing diagnostic trouble codes (DTCs) resets the result.

Possible source
- Open-circuit in the CAN cables between the control module and the Central Electronic Module (CEM).
- Internal error in Driver information module (DIM).

Hint: If several diagnostic trouble codes (DTCs) are stored in the central electronic module (CEM) for communication faults with other control modules in the low speed network, this indicates a common fault in the Control area network, see the wiring diagram. Do not replace the Central electronic module (CEM) unnecessarily.

Fault symptom[s]
- Start inhibitor not operating