VOLVO
MMM-U300362 - Battery voltage. Algorithm Based Failures. Signal compare failure
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?
The multimedia module (MMM) compares its own supply voltage with the CEM's voltage. The code is only worth acting on if it has been active for a while during the same drive and you notice something working worse; otherwise erasing it is enough.
Possible causes
- Supply wire short-circuited to ground
- Open circuit in the supply wire
What you can do
- 1Erase the code; if it does not come back and you notice no problems, no action is needed
- 2If the code returns and the navigation works worse, look for damage and chafing on the supply wire to the multimedia module
- 3With a multimeter you can check that the supply wire has no contact with ground
- 4Have a workshop check the supply and the voltage relative to the central electronic module (CEM) if the fault returns and causes malfunction
Symptoms you may notice1
- The navigation does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.