VOLVO
CEM-8D08 - Left-hand stop lamp. Faulty signal
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 feeds the left-hand brake light from its own output and registers a faulty signal from it. The fault may come from a signal wire shorted to battery voltage, or from an open circuit in that wire.
Possible causes
- The signal wire to the brake light is shorted to battery voltage
- Open circuit in the signal wire to the left-hand brake light
What you can do
- 1Press the brake pedal with the ignition on. If the light stays off the fault is likely permanent; if it works but the code was stored earlier, it is intermittent
- 2Check that the bulb in the left brake light is intact and seated firmly
- 3With the ignition off, use a multimeter to check that the wire to the left brake light is unbroken
- 4Look for chafing and pinched spots along the wire to the left brake light
- 5If the fault remains, have a workshop check the circuit
- 6The fault should be fixed soon, since drivers behind cannot see you brake
Symptoms you may notice2
- The left brake light stays off when braking
- The left brake light is on all the time
General guidance for car owners. Diagnosis on the car can point to a different cause.