VOLVO
REM-7A20 - Subwoofer X-feed, signal or temperature 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) feeds the subwoofer module (SUB) through a driver stage. The fault is stored when the output is shorted to supply voltage, or when the driver stage overheats, and the module then switches the output off.
Possible causes
- Signal cable shorted to supply voltage
- Internal fault in the rear electronic module (REM)
What you can do
- 1Read and note any other fault codes before clearing them, so a workshop can use them in its fault-finding
- 2With the ignition off, use a multimeter to check that the wiring between the REM and the subwoofer module (SUB) has no contact with supply voltage
- 3Look for damaged insulation on the wiring, which can cause intermittent or permanent short circuits
- 4If the fault remains, have a workshop with diagnostic equipment check the REM and the subwoofer
Symptoms you may notice2
- Subwoofer output does not match the chosen setting
- No sound from the subwoofer
What the fault can affect2
- The control module switches off the output to the subwoofer
- On cars built from late September 2005, the output is switched off permanently if the fault has been present over many ignition cycles, until the fault code is cleared
General guidance for car owners. Diagnosis on the car can point to a different cause.