What does fault code UEM-0020 mean?

Diagnostic fault code details for UEM-0020 (Volvo S60 (2001–2009), Volvo S80 (1999–2006), Volvo V70 (2000–2008)). Repair service at OBD Tuning.

VOLVO

UEM-0020 - Rear view mirror. Signal missing

System

Upper Electronic Module (UEM)

Volvo models this fault code applies to

Applies to the following models:

5 models

S60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)

Show models by year and engine (5)

What does this fault code mean?

Although the code is named signal missing, it concerns the anti-dazzle function of the rear view mirror. It is set when the actual tint of the mirror differs from the desired value. The cause can be a defective circuit in the mirror.

Possible causes

Defective circuit in the rear view mirror

What you can do

1Read off the code, clear it and check whether it returns.
2Test whether the anti-dazzle function in the rear view mirror works as it should.
3Look for loose connectors at the rear view mirror.
4If the fault remains, have a workshop replace the upper electronic module (UEM), since it has registered an internal fault.

Symptoms you may notice2

The anti-dazzle function does not work
The anti-dazzle function works poorly

General guidance for car owners. Diagnosis on the car can point to a different cause.