VOLVO
SUB-U200398 - Fibre Optic Communication Bus. Component Failures. Component or system over temperature
System
Subwoofer Module (SUB)
Volvo models this fault code applies to
Applies to the following models:
3 modelsV70 (2008–), XC60 (2009–), XC70 (2008–)
Show models by year and engine (3)
What does this fault code mean?
The reading at the MOST connector's transmitter diode on the subwoofer control module is too high. The control module has therefore become too hot, and it can switch off so that the subwoofer does not play.
Possible causes
- High ambient temperature around the control module
- High power consumption in the control module
- Damaged subwoofer control module
What you can do
- 1Read out and clear the code, then check whether the bass speaker works again
- 2Check that the control module is not boxed in by items placed around it, so that air can circulate
- 3Check that the control module fuse is intact; the owner's manual shows where it is
- 4If the fault remains, have a workshop replace the subwoofer control module
Symptoms you may notice2
- Other audio problems in the car's sound system
- No sound from the bass speaker
What the fault can affect1
- The subwoofer control module is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.