1A5X - 8

Condition







Diagnostic trouble codes (DTCs) are stored if the central electronic module (CEM) registers that communication with the phone module (PHM) is not operating.

NOTE: In the event of CEM-1A5X diagnostic trouble codes (DTCs), the central electronic module (CEM) must not be replaced as the diagnostic trouble code (DTC) indicates a communication fault in the Control area network.

Substitute value

- None.

Possible source

- No power supply to the phone module (PHM).
- Open-circuit in the ground lead to the phone module (PHM).
- Contact resistance in the terminals.
- Open-circuit in the wiring for the CAN low speed network to the phone module (PHM).
- The phone module (PHM) is not intended for this car (for example a used control module with different software/hardware).

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]

- The carphone does not function.
- The menu system does not operate.