VOLVO
CPM-0204 - Glow plugs. Signal missing
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 that the signal wire to the glow plug is broken, so the signal is missing entirely. The cause may be a break in the wire or a damaged glow plug. The heater cannot be activated until the code has been cleared.
Possible causes
- Open circuit in the cable between the CPM and the glow plug
- Damaged glow plug
What you can do
- 1Clear the code and try starting the heater again; if the code returns, the fault is still present
- 2If you have a diagnostic tool, activate the glow plug and see whether the heat rises; if it does not, the fault is probably permanent
- 3Disconnect the connector at the heater and check that the contacts are tight and free from oxidation
- 4Use a multimeter to check that the signal wire from the heater connector to the glow plug is intact; a break means the wire must be replaced
- 5If the fault returns, have a workshop check the glow plug and the wiring to the preheater module
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.