Ask Harry – RMI Senior Technical Advisor investigates a fault with an audio-visual control module

VEHICLE: BMW X3 E83, YEAR: 2003-2006

Q. A customer’s BMW X3 has operating indicators and main beam headlights, but no tell-tales displayed on the instrument cluster. The vehicle’s radio has also stopped working. We can’t figure out what’s causing this, can you help?

A. These faults are most likely being caused by water penetration within the audio-visual control module.

First, check the instrument cluster and light switch for connections and feeds. You should find that it’s the loss of feed from the body control to the instrument cluster that is creating the problem. This will have been caused by water ingress into the audio-visual control module which has damaged the printed circuit board.

Disconnect the AV control unit and you should find that all tell-tale functions return to the instrument cluster and function as normal, aside from radio operation.

The unit will need to be replaced and software downloaded onto the unit, but the source of the water ingress will need to be located and rectified before fitting.

The RMI Technical Helpline is available to discuss, advise and support technicians experiencing problem repairs, help with undocumented fault codes or guide you through wiring diagrams. For more information, please call the IGA member helpline on 0845 305 4230.