VOLVO
CPM-B1D2215 - Coolant Temperature Sensor. General Electrical Failures. Circuit short to battery or open
System
Combustion Pre-heater Module (CPM)
Volvo models this fault code applies to
Applies to the following models:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The CPM reads the DC voltage coming from the heater's coolant temperature sensor. The fault is set when the signal is too high, for example when the cable is shorted to supply voltage or has a break. The heater's function is blocked.
Possible causes
- Contact resistance and oxidation in the connections
- Break in the wiring
- Wiring shorted to supply voltage
- Damaged coolant temperature sensor
What you can do
- 1Check the coolant level and mixture
- 2Check the wiring visually for damage and make sure the insulation is intact
- 3Use a multimeter to check that the cable to the sensor carries no voltage when the ignition is off; if it does, the cable is shorted to positive
- 4Check that the connectors at the sensor and the heater are secure and free from oxidation
- 5If the sensor is damaged or its resistance is wrong, have a workshop replace the coolant temperature sensor
Symptoms you may notice5
- Poor heating in the passenger compartment
- The parking or auxiliary heater does not activate
- The front of the cabin is not warm enough
- The parking heater does not work
- The rear of the cabin heats up slowly
What the fault can affect1
- The heater's function is blocked
General guidance for car owners. Diagnosis on the car can point to a different cause.