Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CEM-DE70

Condition




The diagnostic trouble code (DTC) is generated if the central electronic module (CEM) registers that communication with the headlight control module (HCM) is not operating.

Note! In the event of CEM-DEXX diagnostic trouble codes (DTCs) being stored the central electronic module (CEM) must not be replaced; the diagnostic trouble code (DTC) indicates a communication fault in the Control area network!

The diagnostic trouble code (DTC) can be diagnosed when the ignition has been on for at least 10 seconds.

Substitute value
- None.

Possible source
- Voltage feed to Headlight Control Module (HCM) missing.
- Open circuit on ground cable to Headlight Control Module (HCM)
- Contact resistance in the terminals
- Open circuit in the wiring for the CAN low-speed network to the Headlamp Control Module (HCM).
- Headlight Control Module (HCM) not intended for this car, e.g., used control module with other hardware/software.

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.

Fault symptom[s]
- Headlights/Does not work