Diagnostic trouble code (DTC) information CEM-8A01

Condition 

Fig 1: Identifying Light Switch Module (LSM)

Courtesy of VOLVO CARS OF NORTH AMERICA.

The central electronic module (CEM) communicates with the light switch module (LSM).

The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) receives information from the light switch module (LSM) that the light switch is not in an approved position. For example it is in-between the position for parking lamps and low beam.

The voltage in the central electronic module (CEM) must exceed 10 V for at least 1 second in order for the diagnostic trouble code (DTC) to be detected.

The diagnostic trouble code (DTC) can be diagnosed at ignition switch position II.

Substitute Value 

• Low beam always on.

Possible Source 

• Fault in the communication with the light switch module (LSM)
• Damaged light switch module (LSM).

Fault symptom[s] 

• The low beam is constantly lit.