someone tried to hook up after market headlights to my Audi A4 1.8 turbo, 2001 model. they bridged a wire and as such i lost power in my windows, wipers, horn,indicators, door locks etc. which control module, if any, should be causing that problem?

2 Answers 2


The module in question is the body control module (BCM).

The BCM is the electronic control unit that monitors and controls all of the systems in the car body. Electric windows,A/C functions, electric mirrors,electric locks,security systems, etc.

It communicates with all the other modules via the cars vehicle bus. It drives all the relays the control all the nice gadgets. As with all the vehicular modules it generates fault codes for problem diagnosis.

It seems like the installer of the headlights tapped into the main power feed and using sufficient current to render it inoperable (voltage dropping below threshold or a blown fuse). Logically you would assume that someone could have used the same circuit as the original headlights. I guess not.....


The other answer by resident_heretic is the answer to your direct question, but you should also check the fuses - especially the main ones under the bonnet / hood as when you say "bridged the wire" this may have blown one of the supply fuses...

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