Both of these lights are on in my 2003 Audi A6 3.0 Quattro. I live in MN and we have had -20 degree weather for the past week. I understand the systems are linked together. Has anyone else had this problem? What are the typical problem and costs of service? Thanks.

 

is the car outside all the time or garaged? I'd wait until it totally defrosts and see what happens to the lights. It's possible some ice is affecting the brakes and causing the error light.

If it's the ABS unit, you're looking at $300 to get it re-manufactured and probably a hour labor to remove/re-install. You can drive the car with the unit out, but you don't have ABS. If you go to a dealer, they'll want a grand for a new ABS module.

I've had my ABS module fail and I think just the ABS icon lights. Not sure why the ESP is also lit up but they work in conjunction to apply the breaks when the car loses traction while accelerating or braking.

 

most likely the brake pedal switch. Do you have access to a VagCom? Check the codes.

 

I had the same problem on my Audi A6 -2000. It was caused by one faulty sensor located at the wheels which makes part of the ABS and ESP.