VOLVO
UEM-001C - General courtesy lighting. Signal faulty
System
Upper Electronic Module (UEM)
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 upper electronic module (UEM) monitors the general courtesy lighting switch. The code is set when the button has been pressed down for too long. The cause is either a stuck switch, or the signals from the front reading lamps being short-circuited to voltage. The interior lighting then does not work.
Possible causes
- The general courtesy lighting switch has stuck
- The signals from the front reading lamps, left and right, are short-circuited to voltage
What you can do
- 1Check whether the button for the general courtesy lighting is stuck in the pressed position.
- 2Read off the code, clear it and check whether it returns.
- 3Look for damage and loose connectors in the roof lamp and at the control module connectors.
- 4Use a multimeter to check that the wires from the front reading lamps have no contact with voltage.
- 5If the fault remains, have a workshop check and replace the roof lamp unit if needed.
Symptoms you may notice1
- The interior lighting does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.