VOLVO
CPM-B1D2385 - Overheat Sensor. Bus Signal / Message Failures. Signal above allowable range
System
Combustion Pre-heater Module (CPM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The CPM has logged that the reading at the overheat thermostat or the coolant sensor has gone above the allowed level. The heater is deactivated and the code is set. The cause may be air or a leak in the cooling system, a damaged water pump, a damaged coolant temperature sensor or a damaged overheat protection thermostat.
Possible causes
- Air or leakage in the cooling system
- Damaged water pump
- Damaged coolant temperature sensor
- Damaged overheat protection thermostat
What you can do
- 1Check the coolant hoses for damage and leaks, and look for air in the system
- 2If you have a diagnostic tool, activate the water pump and listen for a buzzing sound; if there is none, the fault is probably permanent
- 3If you have a diagnostic tool, read the temperatures at the overheat protection thermostat and the coolant temperature sensor and note the values for the workshop
- 4Have a workshop measure the resistance of the overheat protection thermostat and replace it if the values do not match
Symptoms you may notice1
- The parking heater does not work
What the fault can affect2
- The heater is deactivated when the code is set
- If the heater is activated again, it makes a new start attempt
General guidance for car owners. Diagnosis on the car can point to a different cause.