VOLVO
CEM-B104321 - Front Axle Sensor. General Signal Failures. Signal too low
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The central electronic module (CEM) monitors the signal from the front position sensor, which senses the headlamp setting. The fault code is stored when the signal is too low compared with the supply voltage. The headlamp side and height adjustment can then be affected.
Possible causes
- Voltage supply shorted to earth
- Contact resistance, oxidation or loose connections in connectors or joints
- Signal wire to the front position sensor shorted to earth
- Break in the signal wire to the front position sensor
- Break in the supply wire to the position sensor
- Damaged sensor
What you can do
- 1Check that the connectors to the front position sensor are secure and free from corrosion
- 2With the ignition off, check the wires to the position sensor for chafing, pinching and breaks, and gently move them
- 3With the ignition off, use a multimeter to check whether the supply and signal wires to the position sensor have contact with earth (the body)
- 4Remedy the fault and clear the fault code. If it returns with intact wires, have a workshop check and, if needed, replace the position sensor
Symptoms you may notice2
- The headlamp side adjustment is wrong or does not work
- The headlamp height adjustment is wrong or does not work
What the fault can affect2
- The light range is held constant
- Side adjustment freezes in the straight-ahead position
General guidance for car owners. Diagnosis on the car can point to a different cause.