VOLVO
CEM-8D01 - Ignition lock light and extra brake light. Signal too low. Intermittent fault
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
This code covers the ignition lock lighting and the extra high-mounted brake light. The fault is intermittent and may not be present right now. The central electronic module (CEM) has registered a short to ground in one of the circuits, and the brake light may have become too hot.
Possible causes
- The high-mounted brake light has become too hot
- Short to ground in the circuit to the ignition lock lighting or the brake light
- Faulty high-mounted brake light
What you can do
- 1Check the connectors at the ignition lock and at the extra brake light for oxidation and looseness
- 2Let the brake light cool down, then check that it comes on when the brake pedal is pressed
- 3With the ignition off, use a multimeter to check that the wire to the brake light has no contact with ground (the body)
- 4If the fault returns, have a workshop with diagnostic equipment check the circuit, since intermittent faults can be hard to find
Symptoms you may notice1
- The high-mounted brake light does not come on when braking
General guidance for car owners. Diagnosis on the car can point to a different cause.