VOLVO
CEM-4F81 - Lamp, seat belt reminder. Signal too low
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CEM powers the seat belt reminder lamp directly through an output. If the output level is too low, the code is set. The seat belt lamp then does not light when the reminder is activated.
Possible causes
- The signal wire is shorted to ground
What you can do
- 1With the ignition on, check whether the seat belt reminder lights when activated
- 2Check that the connector to the seat belt reminder lamp is seated and not corroded
- 3Use a multimeter to check that the wire to the lamp is not shorted to ground
- 4After the work, clear the code and check that the seat belt reminder works
Symptoms you may notice1
- The seat belt lamp does not light
General guidance for car owners. Diagnosis on the car can point to a different cause.