I have a 2001 A6 2.7T and I have been fighting a mystery for the past 6 months.
I would appreciate any input.
Under certain conditions while accelerating the traction control light would start flashing and I can feel that the car is loosing power since brakes are applied and throttle is restricted due to the traction control engaging but I don't know what cause is that.
Sometimes the ABS light and traction control will come on for 10 seconds and that disappear.
Some people have told me that it could be caused be MAF which I have replaced, vacuum lines which I have replaced, Air filter, check valves which I have replaced.
Any idea anyone?
Thank you.

 

wheel bearing maybe? could be causing the ABS light to come on, or brake lining sensors may be screwed up.

 

I'm 99% sure that it's engine related because it's happening only under certain load.
There is something wrong with the engine vacuum lines or something like that because I'm getting all kind of codes such as;
17819 Bank2 secondary air system flow to low (Static),
17819 Bank1 secondary air system flow to low (Static),
16487 mass or Volume air flow circuit high input Intermittent, air flow sensor (which I replaced),
17863 exhaust gas temperature sensor 1 - g235 Implausible signal Intermittent.

 

Any other suggestions anyone?
Please Help!!!

Thank you

 

Jorka,
You might find this article to be of interest:

http://www.vaglinks.com/Docs/Audi/C5...iagnostics.pdf