Diagnostic Trouble Code CEM-8D0A

Condition

Fig 1: Identifying Tail Lamps

Courtesy of VOLVO CARS OF NORTH AMERICA.

The central electronic module (CEM) supplies voltage to the emergency brake light directly via an output.

The diagnostic trouble code is stored if the control module detects:

Incorrect signal lasts longer than 1 second.

The control module's test for the diagnostic trouble code (DTC) starts in the event of:

Activated stop lamp.

NOTE:

The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.

Substitute Value

None.

Possible Source

Short-circuit to ground in the voltage supply cable.

Fault symptom[s]

Tail light/Brake light does not work
Tail light/Backup lights constantly lit