VOLVO
REM-5A31 - Relay, rear A/C. Signal too high
System
Rear Electronic Module (REM)
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 rear electronic module (REM) controls the relay for the rear A/C and checks the signal to its coil. If that signal is too high, which may be due to a short to supply voltage in the relay circuit or a defective relay, the code is set. The rear A/C then does not work.
Possible causes
- Short circuit to supply voltage in the relay circuit
- Defective relay
What you can do
- 1If you have a diagnostic tool, activate the rear A/C relay and listen for a click
- 2Check that the rear A/C relay is in place and does not appear damaged
- 3If the relay is defective or the fault remains, have a workshop replace the rear A/C relay
Symptoms you may notice1
- The rear A/C system does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.