VOLVO
IHU-B1D7912 - Microphone Input. General Electrical Failures. Circuit short to battery
System
Infotainment Head Unit (IHU)
Volvo models this fault code applies to
Applies to the following models:
9 modelsS60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The microphone's signal wire is monitored by the infotainment head unit (IHU). The code is stored when the voltage on the wire is too high, which suggests a short-circuit to supply voltage.
Possible causes
- The signal wire to the microphone is short-circuited to supply voltage
What you can do
- 1Read and clear the code, then check whether it comes back
- 2Check that the fuses are intact
- 3Make a test call using hands-free and ask the other person whether they can hear you
- 4Check the microphone wiring for chafing, damage and places where it may have touched a live wire
- 5If the fault remains, have a workshop trace the microphone and the wiring further
Symptoms you may notice1
- The AUX panel does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.