Diagnostic Trouble Code (DTC) Information CEM-5F3A

Condition 

Fig 1: Additional Heater And Parking Heater

Courtesy of VOLVO CARS CORPORATION

The central electronic module (CEM) checks the communication with the combustion preheater module (CPM).

The diagnostic trouble code (DTC) is stored if the central electronic module (CEM) registers that the signal in the circuit for the water pump is too high.

The diagnostic trouble code (DTC) can be diagnosed when the heater is activated.

Substitute Value 

• None.

Possible Source 

• Short-circuit to supply voltage in the signal cable
• Damaged water pump.

Fault symptom[s] 

• Poor heating in the passenger compartment
• The parking heater does not operate.