VOLVO
CPM-6408 - Control module. Internal fault
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 found an internal fault. The heater switches off, and when it is started again it makes a new start attempt. If the fault is no longer present when the ignition is switched on again, it was probably temporary.
Possible causes
- Internal fault in the combustion preheater module (CPM)
What you can do
- 1Restart the heater and check whether the fault code returns
- 2Check that the battery has good voltage at start, since interference during starting can cause the fault
- 3If the fault returns, have a workshop replace the CPM
Symptoms you may notice2
- Poor heating in the passenger compartment
- The parking heater does not work
What the fault can affect2
- The heater switches off when the fault code is set
- If the heater is started again, it makes a new start attempt
General guidance for car owners. Diagnosis on the car can point to a different cause.