A3 Sportback 8P 2012 Lighting System Gone bonkers

[peepsie2]

Suddenly the dash gives a load of warnings for different external lights. Some of which are false (ie. light still working - eg. brake lights) -  but many are correct in that the lights are not working, but the bulbs check OK on tester (eg. headlight, cluster of 3 rear lights). I am suspicious it is some sort of lighting module gone wonky. I can only see one fuse (No 1) which even mentions lighting. Should I be looking at relays?

Local garage reckons that the computer connection won't be much help, and I have to check all bulbs and relays.

Any one got any experience with this?

[peepsie2]

Ha! Fixed!

I am going to reply to my own post as it might help others. After 2 days of turmoil and testing of countless fuses and lamp units and bulbs I eventually cottoned on to realise that the Body Control Module (BCM) is probably the only candidate to cover the list of N/Working lighting items. In the manual for the facelift A3 8PA 2.0 Diesel it lists two BCM module fuses, one for left and one for right. In this model there is only one BCM fuse (fuse 16 engine compartment). The fuse was OK, but the connection dodgy, i.e tarnished and showing signs of overheating. I cleaned fuse and socket up, and put switch cleaner on and everything cleared up instantly.

However, I presume in the facelift model they decided to go to one fuse, and I guess it has a higher load, so I anticipate further problems as the fuse socket is a bit on the loose side.

[cliffcoggin]

Good detective work. It's hard to beat old fashioned testing as opposed to reading a meaningless code on a computer.