VOLVO
CPM-U300316 - Battery Voltage. General Electrical Failures. Circuit voltage below threshold
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 heater control module has received too low a supply voltage for a period of time. The fault code is then set, and the heater cannot be started until the fault code has been erased. The cause may be a poorly charged battery, a connection with high resistance, or a blown fuse.
Possible causes
- Poorly charged battery
- Contact resistance in the control module connections
- Blown fuse
What you can do
- 1With the ignition off, check that the fuse for the heater is intact. Replace it with a new one of the same rating if you suspect it is half-blown.
- 2Charge the battery fully and measure the battery voltage with a multimeter. A low voltage means the battery needs charging or replacing.
- 3Check the connectors to the heater control module for corrosion and looseness. Clean or tighten them.
- 4If you have a diagnostic tool: activate the heater after the work and check that it starts and works as it should.
- 5If the battery is good and the connectors are in order but the fault remains, have a workshop check the control module and its supply.
Symptoms you may notice1
- The parking heater does not work
What the fault can affect1
- The heater cannot be started until the fault code has been erased
General guidance for car owners. Diagnosis on the car can point to a different cause.