VOLVO
PDM-B1C3929 - Key Lock Switch. General Signal Failures. Signal signal invalid
System
Passenger Door Module (PDM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–)
Show models by year and engine (4)
What does this fault code mean?
Although the code is titled as a key lock switch, it applies to the front door lock motors. The driver and passenger door modules (DDM/PDM) receive information on whether each lock motor is locked or unlocked. The code is set if lock and unlock commands show up together, which means the signal does not add up.
Possible causes
- An internal fault in the control module
What you can do
- 1Read the code, clear it and lock and unlock the car with the key to see whether the code comes back
- 2Check the fuses for the central locking in the fuse box and make sure they are intact
- 3Check that the lock motor in the door that does not lock or unlock is secure and that its connector is free from moisture and oxidation
- 4If you have diagnostic equipment, read the lock motor status in live data and check that it shows locked or unlocked when you lock and unlock
- 5If the fault remains: have a workshop check the lock motors and the door module
Symptoms you may notice1
- One door does not lock or unlock
General guidance for car owners. Diagnosis on the car can point to a different cause.