Diagnostic Trouble Code (DTC) Information CEM-5F39

Condition 

Fig 1: Identifying Parking Heater

Courtesy of VOLVO CARS CORPORATION

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

If Central electronic module (CEM) registers that the flame goes out in an non-allowed way during operation, the diagnostic trouble code is generated.

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

Substitute Value 

• None.

Possible Source 

• No fuel supply
• Flame sensor clogged with soot
• Damaged flame sensor.
• Contact resistance in the control module connectors
• Open-circuit in the signal cable
• Short-circuit to supply voltage in the signal cable
• Open-circuit in the ground lead

Fault symptom[s] 

• Poor heating in the passenger compartment.
• Parking heater/Does not work