VOLVO
CEM-B103C16 - Left Headlamp Control. General Electrical Failures. Circuit voltage below threshold
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The left main headlamp control unit (LHCU) receives too low a voltage, according to the fault code. It drives the headlamp motors, so side and height adjustment and automatic high beam can be affected. The fault may lie in the supply or in the control unit.
Possible causes
- Incorrect voltage supply to the left main headlamp control unit (LHCU)
- Supply wire shorted to earth or voltage
- Damaged left main headlamp control unit (LHCU)
What you can do
- 1Check that the fuses for the headlamps are intact
- 2With the ignition on, use a multimeter to check the supply wire to the left headlamp. Too low a voltage, or none, points to a supply fault
- 3With the ignition on, check whether the wire has contact with earth or voltage, since a short circuit can cause too low a voltage
- 4Remedy the fault and clear the fault code. If it returns, have a workshop check the left headlamp control unit
Symptoms you may notice4
- Headlamp side adjustment does not follow the steering wheel correctly, or does not work
- Headlamp height adjustment is wrong or does not work
- A message appears in the information display
- Main beam with automatic high beam control does not work
What the fault can affect2
- The headlamp light range is locked at one fixed level
- Side adjustment stops in the straight-ahead position
General guidance for car owners. Diagnosis on the car can point to a different cause.