VOLVO
CPM-1418 - Water pump. Signal too high
System
Combustion Pre-heater Module (CPM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The CPM has registered a signal that is too high on the cable to the water pump. The cause may be a short circuit to supply voltage in the cable or a damaged water pump. The heater cannot be started until the code has been cleared.
Possible causes
- Live-voltage short in the wire running from the CPM to the water pump
- Damaged water pump
What you can do
- 1Clear the code and start the heater again; if the code returns, the fault is still present
- 2If you have a diagnostic tool, activate the water pump and listen for a buzzing sound; if it does not start, the fault is probably permanent
- 3Check that the connectors at the water pump and the heater are tight and free from oxidation
- 4Use a multimeter to check that the cable to the water pump carries no voltage when the heater is off; if it does, the cable is shorted to positive
- 5If the fault returns, have a workshop check the water pump and the wiring
Symptoms you may notice2
- Poor heating in the passenger compartment
- The parking heater does not work
What the fault can affect1
- The heater cannot be activated until the fault code has been cleared
General guidance for car owners. Diagnosis on the car can point to a different cause.