VOLVO
CPM-B1D2211 - Coolant Temperature Sensor. General Electrical Failures. Circuit short to ground
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 shorted to earth, which gives a signal that is too low. The causes may be an incorrect coolant level, a damaged coolant pump or cooling circuit, or a damaged sensor or cable.
Possible causes
- Coolant level outside the permitted range
- Damaged coolant pump
- Damaged cooling circuit
- Damaged coolant temperature sensor
- The cable between the CPM and the coolant temperature sensor is shorted to earth
- Contact resistance, oxidation or loose connections
What you can do
- 1Check the coolant level and mixture, and top up with the correct mixture if needed
- 2Check that the coolant hoses are not pinched or deformed
- 3Check the cable to the coolant temperature sensor visually for damage and make sure the insulation is intact
- 4Use a multimeter to check that the cable has no contact with earth (the body); if it does, the cable is shorted
- 5If the fault remains, have a workshop check the coolant pump, the cooling circuit and the sensor, and drain, refill and bleed the system if needed
Symptoms you may notice5
- The parking heater does not work
- The rear of the cabin is not warm enough
- The front of the cabin is not warm enough
- The heater does not work
- The cabin heats up slowly
What the fault can affect2
- The heater's function is blocked
- Activation is blocked until the fault is repaired and the code is cleared
General guidance for car owners. Diagnosis on the car can point to a different cause.