Hi everyone.

I have an Audi A4 '97 model 2.6L ABC.

There is an intermittent fault that is gradually getting worse and worse.

From cold (most of the time) it behaves normally, until....

The dash lights up like a christmas tree.. pretty much all the warning lights come on including the ABS light and every gear light (auto box). I lose the signal to the tacho. 5 beeps follow closely!!

I have had the car on a VAG-COM and the only faults it shows are Engine Speed Sensor and Brake Light Switch.

To add to the mystery and before I start throwing cash at it (which is in demand everywhere else at the moment!!).. from time to time it is so intermittent that you can actually see the tacho failing, then coming back to life, before it hits 0 revs!! BUT... when I touch the brake it kills it totally... then release the brake and it comes back again, albeit very erratically.

I have been told by one Audi mechanic to change the brake light switch as it has 4 wires.. 2 for the lights and 2 for the ABS.. BUT.. mine only has 2 wires.. black/red and yellow/red.. these appear also in the ABS control plug at the ABS unit.. do they go straight there and are the lights controlled by the ABS unit? I have also been told that the Tacho signal passes through the ABS unit also. I would like to think that the ABS unit hasnt filled its undies with cottage pie as they are really expensive here in NZ!...

It also occasionally comes good after some time and resets itself on the move and the warning lights go out. The Gbox lights then reset after slowing to a stop.

Any ideas anyone please?? your help on this is much appreciated...

Thanks

Ady

 

Any idea`s anyone please? Bad earths etc?? Thanks