Diagnostic trouble code (DTC) information CEM-5F3D

Condition 

Fig 1: Identifying Additional Heater And Parking Heater

Courtesy of VOLVO CARS OF NORTH AMERICA.

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

The diagnostic trouble code (DTC) is stored if the central electronic module (HEM) registers that the signal in the circuit for the combustion fan is too low or missing.

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

Substitute Value 

• None.

Possible Source 

• Contact resistance in the control module or the combustion fan connectors
• Open-circuit in the signal cable
• Open-circuit in the power cable
• Short-circuit to ground in the signal cable
• Damaged combustion fan.

Fault symptom[s] 

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