VOLVO
CEM-B109211 - Daytime Running Light Relay. General Electrical Failures. Circuit short to ground
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The CEM feeds power to the two daytime running lights and watches the voltage on the wires. The fault shows that the voltage supply to the lights is too low, which can be caused by a short to ground in the supply wire. The fault is checked when the daytime running lights are active.
Possible causes
- The voltage supply wire is shorted to ground
What you can do
- 1Read off and note the code, clear it and drive with the daytime running lights on to see whether it returns
- 2Check that the fuse for the daytime running lights is intact
- 3Check that the connectors to both daytime running lights are fully engaged and not corroded, and that the wires are not chafed
- 4Use a multimeter (ignition off, connectors unplugged) to check that the supply wires have no connection to ground
- 5If you have a diagnostic tool, activate the daytime running lights with the tool and check that both come on
- 6If the fault remains, have a workshop check the wiring to the daytime running lights
Symptoms you may notice3
- Yellow warning symbol and text message in the display
- The front fog lights or daytime running lights do not work
- The bulb failure warning in the instruments comes on or behaves abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.