Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CEM-5F40

Condition




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 fuel pump (FP) is too low.
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 fuel pump connectors
- Short-circuit to ground in the signal cable
- Open-circuit in the signal cable
- Open-circuit in the power cable
- Damaged overheat protection thermostat
- Damaged fuel pump.

Fault symptom[s]
- Poor heating in the passenger compartment.