VOLVO
CPM-E001 - Control module communication. Faulty communication
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 heater control module cannot communicate on the CAN network, and it then disconnects itself from the network. It stays switched off until the power supply has been broken, and makes new attempts when the power is connected again. The fault may be caused by a short or an open circuit in the CAN wiring, or by an internal fault in the control module or in another module on the same part of the network.
Possible causes
- Short circuit between the CAN wires
- Open circuit in one of the CAN wires
- Internal fault in the heater control module
- Internal fault in another control module on the same part of the CAN network
What you can do
- 1Check that the battery has good voltage, as low voltage can make control modules lose contact with the network.
- 2With the ignition off, check that the connectors to the heater are firmly seated and clean, as looseness can cause communication faults.
- 3If you have a diagnostic tool: read the fault codes in several control modules. Faults in several modules at the same time may point to a fault in the network.
- 4Do not replace control modules before a workshop has traced the network, as the fault may lie in the wiring or in another module.
- 5Have a workshop measure the CAN network with diagnostic equipment. The measurement requires central control modules to be disconnected.
Symptoms you may notice2
- Poor heating in the cabin
- The parking heater does not work
What the fault can affect2
- The control module disconnects itself from the CAN network (bus-off)
- The control module makes new communication attempts when the power is connected again
General guidance for car owners. Diagnosis on the car can point to a different cause.