Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information CPM-B1D2313

Condition
The combustion preheater module (CPM) monitors the coolant temperature of the heater using the overheating sensor in the heater. The sensor circuit in the control module is internally connected to the circuit for controlling the fuel pump (FP). To prevent the heater from overheating, the fuel pump (FP) stops when the sensor is tripped.
The diagnostic trouble code (DTC) is stored if the control module detects that:
- The temperature is greater than 150 °C and the fuel pump (FP) is stopped.
The control module's test for the diagnostic trouble code (DTC) starts in the event of:
- Heater started.

Note! The control module can only detect the fault once the test has been started and the diagnostic trouble code (DTC) is stored when the conditions are met.





Substitute value
- Heater's function blocked.

Possible source
- Contact resistance and oxidation in the terminals.
- Open-circuit in the wiring.
- Damaged overheating sensor.
- Blocked or choked circulation of coolant.

Fault symptom[s]
- Poor heating in compartment
- Activation parking-/auxiliary heater; no function