Diagnostic Trouble Code (DTC) Information CEM-8A20

Condition 

Fig 1: Identifying Right-Hand Gas Discharge Lamp Module

Courtesy of VOLVO CARS OF NORTH AMERICA.

The central electronic module (CEM) communicates with the left-hand gas discharge lamp module (GDL).

The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) receives information from the left-hand gas discharge lamp module (GDL), which registers that the left-hand gas discharge lamp module (GDL) does not have parameters for the vehicle type.

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value 

• The shortest headlamp range will be used.

Possible Source 

• Left-hand gas discharge lamp module (GDL) not programmed with vehicle-specific parameters.

Fault symptom[s] 

• Automatic headlamp range control is not functioning.