VOLVO
MMM-U300316 - Battery Voltage. General Electrical Failures. Circuit voltage below threshold
System
Multi Media Module (MMM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsS80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–)
Show models by year and engine (4)
What does this fault code mean?
Although the code is named battery voltage, it concerns the multimedia module's (MMM) own supply voltage, compared with the CEM's voltage. The code is set when that supply is too low, which may come from a supply wire that is short-circuited to ground or has an open circuit.
Possible causes
- Supply wire short-circuited to ground
- Open circuit in the supply wire
What you can do
- 1Check the fuses for the multimedia system and make sure none has blown; if one has, check the wire for a short to ground before a new fuse is fitted
- 2Look for damage, chafing and breaks on the supply wire to the multimedia module
- 3With a multimeter you can check that the supply wire has no contact with ground (the body)
- 4Check whether the connectors at the multimedia module are loose or oxidised
- 5Have a workshop check the supply to the multimedia module if the fault remains
Symptoms you may notice1
- The navigation does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.