Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information HCM-B1A5701

Condition
The Headlamp Control Module (HCM) communicates with the Left headlamp control unit (LHCU).

The diagnostic trouble code (DTC) is stored if the control module detects that:
- The Left headlamp control unit (LHCU) registers the vertical motor circuit has incorrect voltage or too high temperature.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Ignition switch position II.

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
- None.

Possible source
- Faulty power supply.
- Damaged Left headlamp control unit (LHCU).
- Temperature too high.
- Short-circuit to supply voltage in the signal cable.
- The signal cable is short-circuited to ground.
- Open circuit on signal cable.

Fault symptom[s]
- Automatic vertical aim control does not work
- Text window and warning symbol/Text message