VOLVO
REM-DD20 - Tilt sensor or siren, communication fault
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) communicates with either the alarm's inclination sensor module (ISM) or the siren (BBS), depending on when the car was built. If a serious interruption blocks that communication, the code is set and the alarm may give false alarms. Cars built before mid-July 2011 have the ISM, and later cars have the siren.
Possible causes
- Short-circuit between the signal cables
- Open circuit in one of the signal cables
- Internal fault in another control module on the same part of the network
What you can do
- 1Read and clear the code, then check whether it comes back
- 2With the ignition off, check that the connector at the rear electronic module (REM) is fully seated and free from oxidation
- 3With a multimeter, check that the signal cable to the inclination sensor or siren has no open circuit and no contact with ground or voltage
- 4With diagnostic equipment, check whether the inclination sensor or siren is listed among the control modules with the ignition on
- 5If the cable is intact, the REM, inclination sensor or siren may be faulty; replace the defective part
Symptoms you may notice1
- The alarm may give false alarms
General guidance for car owners. Diagnosis on the car can point to a different cause.