VOLVO
CEM-1C22 - Relay, infotainment. Signal too low/Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
1 modelXC90 (2003–)
Show models by year and engine (1)
What does this fault code mean?
The CEM registers that the signal to the coil of the infotainment relay is too low or missing. The cause may be a missing relay, a defective relay, or contact resistance in the relay socket. The audio system does not work.
Possible causes
- The relay is missing
- A defective relay
- Contact resistance in the relay socket
What you can do
- 1Check that the infotainment relay is seated in its socket. If it is missing, fit an identical one
- 2Remove the relay and check that the contacts in the socket are clean and not corroded. Refit the relay
- 3Switch the ignition on, then switch the audio system on and off, and check that the relay clicks. A click shows it works
- 4If it does not click, replace the relay with an identical one. If the audio system then works, the old relay was defective
- 5Use a multimeter to check that the wire to the relay has no break. After the work, clear the code and check the audio system
Symptoms you may notice1
- The audio system does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.