What does fault code CEM-8A0B mean?

Diagnostic fault code details for CEM-8A0B (Volvo S60 (2001–2009), Volvo S80 (1999–2006), Volvo V70 (2000–2008)). Repair service at OBD Tuning.

VOLVO

CEM-8A0B - Relay, daytime running lamp. Signal too high

System

Central Electronic Module (CEM)

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?

CEM picks up a high signal on the status flag when the relay control for the daytime running lamp is activated. The fault code is set because the control to the relay is short-circuited to battery voltage, and the front lighting then does not work.

Possible causes

Relay control for the daytime running lamp relay short-circuited to battery voltage

What you can do

1Switch the ignition off and check the daytime running lamp relay, making sure it is seated and its contacts are not corroded
2Use a multimeter to check that the wire to the relay control has no contact with battery voltage
3Remedy what is found and clear the fault code
4If no fault is found, try a new relay

Symptoms you may notice1

The front lighting does not function

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