Diagnostic Trouble Code (DTC) Information CPM-B1D2215

Condition

The combustion preheater module (CPM) checks the direct voltage from the coolant temperature sensor in the heater.

The diagnostic trouble code (DTC) is stored if the control module detects that:

Direct voltage from the engine coolant temperature sensor is higher than 4.84 V.

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.

Fig 1: Identifying Coolant Temperature Sensor

Courtesy of VOLVO CARS CORPORATION

Substitute Value

Heater's function blocked.

Possible Source

Contact resistance and oxidation in the terminals.
Open-circuit in the wiring.
Short-circuit to supply voltage in the wiring.
Damaged engine coolant temperature (ECT) sensor.

Fault symptom[s]

Poor heating in compartment
Activation parking-/auxiliary heater; no function