Hello, on my 97 A6 there is an extreme clicking noise / relay noise from the relay near the left foot place, in the drivers seat.

It only happens when releasing the brake pedal, with the car in park. I have tried to change the relay, with no luck, there is also a noise coming from the transmission in tune with the relay noise.

Releasing the brake pedal, should engage the shift lock, on the automatic transmission, so that the car cant be put into drive, without the foot on the brake pedal, and this works, however it is this lock switch, that buzz in tune with the relay.

It's clear to me that the relay should be engaged with the brake pedal pressed in, and when the brake pedal is released, it should come off, but insted it just click/buzz like crazy.

Must be something wrong with the signal controlling the relay.

One idea I have been having is the brake pedal switch beeing defective, but judging from outside the car, it works fine.

Any ideas are welcome!

I have never heard of anyone having had this problem before.

I say, if it just a noise - ignore it.

Hello, to put it very short

With brake pedal out it should be no noise (beside a single click when releasing pedal/engaging shift lock).

With brake pedal in, the auto trans shift lock should go off (it does), and a relay click should be heard.

My car however, have startet to have an extreme relay buzz, with the relay, and shift lock, going on and off uncontrolled with the brake pedal out, when in park.

No issues with brake lights, shift lock relay, or AT shifting..

I have narrowed the problem to something in the circuit controlling the relay, and the brake pedal switch is a part of the circuit.

With the brake pedal in, there should be connection to ground, with brake pedal out, no connection, and I am having static connection to ground with brake pedal out, judging from the relay noise...

I have lived with it some weeks hoping it would pass, but it dont.

Hey Carped1em

Im having a similar problem. It is definatley the Control unit clicking, but ive even replaced mine and it still clicks and its damn annoying.

Ive made a thread too to see if anyone can help, my problem is slightly different to yours as my brake light are affected. Might be worth keeping an eye on tho:

<a href="http://forums.audiworld.com/a6100/msgs/35869.phtml">http://forums.audiworld.com/a6100/msgs/35869.phtml</a>

Hey Carped1em -

I have the same issue. I posted the question about 3 weeks ago, but no bites.

I've had the clicking relay since I bought my 94 100s in December 2003. Mine will click intermittently, sometimes once, sometimes a bunch in rapid succession. When it occurs, I can see my headlights and dashlights fluctuate.

I haven't been able to isolate the problem or cause, but it seems to be merely annoying, not threatening.