VOLVO
REM-4F91 - Sensor, seat belt reminder. Signal too low
System
Rear Electronic Module (REM)
Volvo models this fault code applies to
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?
The rear electronic module (REM) monitors the signal from the seat belt reminder sensor in the passenger seat. If the signal is too low the code is set, and a signal wire shorted to ground or a faulty sensor can cause this. A general warning lamp then comes on.
Possible causes
- Signal wire shorted to ground
- Defective seat belt reminder sensor
What you can do
- 1Read and note the fault code, clear it and test drive the car to see whether it returns
- 2Check the connectors at the rear electronic module and at the seat belt reminder sensor for contact resistance, oxidation and loose contacts
- 3Look for chafing on the signal wire to the seat belt reminder sensor and check that it is not shorted to ground
- 4If the fault remains, have a workshop trace it further and replace the sensor if needed
Symptoms you may notice1
- General warning lamp lit
General guidance for car owners. Diagnosis on the car can point to a different cause.