Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information HCM-B103C88

Condition




The Headlamp Control Module (HCM) both transmits and receives information via a standardized serial communication method - LIN (Local Interconnect Network). The control module checks the communication with the Left headlamp control unit (LHCU).
The diagnostic trouble code is stored if the control module detects:
- Communication error with the left headlamp control unit (LHCU).
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Ignition switch position II.
- Battery voltage higher than 10 V.

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

Possible source
- Short-circuit to ground in the signal cable.
- The signal cable is short-circuited to supply voltage.
- Contact resistance or oxidation in the terminals or connections.
- Open circuit on signal cable.
- Damaged Left headlamp control unit (LHCU).

Fault symptom[s]
- Headlights/Vertical adjustment not influenced by steering wheel
- Headlights/Headlight aim is off
- Text window and warning symbol/Text message