U000100 (Headlamp Control Module - HCM)

Diagnostic trouble code (DTC) information HCM-U000100

Condition
The control modules transmit and receive information via a standardized serial communication method - CAN (Control Area Network).
The diagnostic trouble code (DTC) is stored if the control module detects that:
- Communication on the CAN network is interrupted by another control module on the CAN network or by the control module's own message causing interference on the CAN network.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Starting the control module's CAN communication.

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. In the event of system communication problems, it is not possible to communicate with the control module. Therefore it will only be possible to read off the fault if it is intermittent.





Substitute value
- Control module shuts itself off ("bus-off").

Hint: The control module is off until the power supply has been broken. When the power supply is connected the control module will make a new attempt to communicate.

Possible source
- Short-circuit between the control area network (CAN) wiring.
- Open-circuit in the control area network (CAN) wiring.
- Internal fault in another control module in the same part of the control area network (CAN).
- Internal fault in the control module.

Fault symptom[s]
- Active Bi-Xenon light; No Functionality
- Message in information display
- Indicator lamp Active Bi-Xenon light; Flashing