Diagnostic Trouble Code (DTC) Information CEM-8B09

Condition 

Fig 1: Identifying Rheostat

Courtesy of VOLVO CARS CORPORATION

The central electronic module (CEM) powers the background lighting in the light switch module (LSM) directly via an output.

A DTC is stored if the Central electronic module (CEM) registers that the resupplied signal does not correspond with the outgoing signal.

The DTC can be diagnosed in key position I and II and dipped beam off.

Substitute Value 

• None.

Possible Source 

• Short-circuit to supply voltage in the signal cable for the background lighting for the light switch module (LSM)
• Open-circuit in the signal cable for the background lighting for the light switch module (LSM).

Fault symptom[s] 

• The lighting in the instrument panel does not function.