2005 A4 TDi 130

I have recently bought a 2005 a4 tdi estate b6 shape. Im having major issues with the brake lights being permanently stuck on. I've tried replacing the brake light switch (twice both with new genuine switches and following the correct fitting instructions, just incase one was faulty out of the box!) and also the brake light bulbs.
When the ignition is off, there is no problem with the brake lights they all work as they should, the problem arises as soon as the ignition is switched on, the lights come on and stay on.
Occastionally the high level brake light works normally as it should but the 2 lower side brake lights are always jammed on!
If anyone has any ideas I would be grateful

Ferrari328

Did someone rewire them so both are on as rear fog lights? What happens if you turn on the rear foglight using the light switch?

2005 A4 TDi 130

I dont think that switching the fog lights on makes any difference at all!
I pulled the rear lights out and looked at the wiring and it is all original.
One thing I have found today is that there is a permanent live feed from the central control module to the red and white wire once the ignition is switched on. If I unplug the multiplug and live this wire from my test probe it switches on the brake lights.
I tried another module in it with the same part number but no difference whatsoever. I phoned the dealer to check if it is the correct module for the car and sure enough it is.
I thought I was getting somewhere but no, now back to the drawing board!

cycle171

2005 a4 tdi 130 my 2007 a4 is doing the same thing, dealer spent the day on it and couldnt fix the problem. have you had any luck let ?

ECS Tuning-Audi

Seems like the brake light circuit isn't closing. Meaning maybe there's a wire some where that's constantly supplying the brake lights power when they should be off.

Might have to back track through the wiring harness to see if that's valid.

It's about the only logical explanation - definitely odd two switches would not change the out come.

Jason

A4Audi4Fun

Brake lights really on or is it the DRL mode in operation? On the 2005 Canadian models, the front fogs function as the DRL and the front parking lights and rear tail lights are always on.

Gary Higby

I am experiencing same brake light problem with my 07 a4. Did you ever
solve yours ?