Diagnostic trouble code (DTC) information CEM-3F81

Condition 

Fig 1: Identifying Central Electronic Module (CEM) and Starter Relay

Courtesy of VOLVO CARS OF NORTH AMERICA.

During start attempts the central electronic module (CEM) grounds an input on the starter relay so that the starter motor can turn the engine. The control module also checks the voltage level at the output connected to the starter relay.

The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) registers a short-circuit to supply voltage in the output connected to the starter relay.

The diagnostic trouble code (DTC) can be diagnosed at ignition switch position III (start attempt).

Substitute Value 

• None.

Possible Source 

• Short-circuit to supply voltage in the cable between the central electronic module (CEM) and the starter relay.

Fault symptom[s] 

• The starter motor does not turn.