I have a 2001 Audi A6 2.7T MT with about 130,000 Miles. I recently took it in to the shop to have the clutch replaced.
The clutch replacement was good. The only problem was when I got the car back the ABS started activating at very low (<3MPH)speeds while braking. So I took it back to the shop and told them about the issue. Their first reaction was that it was a wheel sensor as was mine. I left it with them to test and they came back and said they did not know what the problem was since all the wheel sensors were checked out and the abs light is not on to indicate that there is a problem. So I have been left to solve the problem so they can fix it.

 

You need a VAG COM to diagnose it. It could be a faulty brake light switch or a wheel speed sensor. Your tires aren't bald are they?

 

The tires are not bald and I assume the shop I took my car to used the VAG-COM to diagnose it and came up with nothing.
The problem appeared immediately after they replaced the clutch which makes me think they did not reinstall something correctly or they broke something.
Could you explaing why it could be a faulty brake light switch.

 

I woud check the toner rings on the axles. No reason to pull the axles, but they may have pulled them to remove the trans and damaged the toner rings or wheel speed sensors.

 

I took the car into the shop to have them inspect the toner rings.
The did not find anything wrong with the toner rings, but noticed that they were very dirty.
They cleaned them and the problem went away. I would not think any amount of dirt would keep them from working, but maybe I don't understand how the sensor works. I assume it is a magnetic pickup that detects the "cogs" on the toner ring.
Not that it matters much to me since it is fixed.

Thanks for pointing me in the right direction