Hi,
I am having a problem with my 02 A6 4.2. Sometimes ESP light and ABS light come on at the same time and stay on until i shut down the engine. It is not all the time. For example one day i never see them coming on and the other day they come on after 15 min driving. I already checked the codes and there is none. Do you guys have any idea?
Thanks

 

Possibly a faulty ABS controller, located under the hood on the Brake block

 

If you have VAGcom check the measuring blocks to the brake controllers. If there is no communication and can't read the info, then most likely your ABS controller is bad. But if you can read the info, I say check the brake switch.

 

I do not have VAGcom. Do regular repair shops have it?

By the way the brake switch is this right? (click here to see the switch)

I can change the brake switch and see what happens. It is not an expensive part.

 

European shops dealing with VWs and Audis should have it for sure. Yeah, the switch is really inexpensive and is easy to replace. Try that first and see if it helps. Otherwise you can get your ABS controller rebuilt.

 

I ordered this. Probably will get it next week. Hopefully new switch will resolve the problem.

 

I wanted to ask this before i change the light switch. I already ordered the switch however today i checked my brake lights and they are working properly. I mean when i touch the brake pedal, the brake lights come on. Isn't that a sign that shows the brake light switch is OK?

Secondly, is there anybody live in San Antonio, TX who has VAGcom, and can help me to check brake controller? I went two repair shops, they ask 150 bucks for just checking.

 

ABS, ESP and brake light switch are all interconnected. There were many instances, if you research the forum, where the cause of the same symptom was a faulty brake switch. Considering the part cost is so cheap, unless you have a VAGcom to check as I mentioned, it is worth a try to replace the switch.

 

Actually i realized something today. I read somewhere that the brake lights are supposed to come on as soon as you touch the brakes. In my case i need to press the brake pedal almost half way down in order to make brake lights come on. So it is obvious that something is wrong with that switch. I was curious and i asked the dealer that how much they charge to change it, they told me that they charge 180 bucks + part. They are crazy. I am gonna change it myself anyway. I will get it next week, i will post the result next week. Thanks for the answers guys.

By the way, i ordered VAGcom as well. My next car will be a definatelly a Audi so i will save money in the long run when it comes to diagnosis and modifying the settings. First thing i am going to change is DRL I want to be able to us fogs without turning on headlights.

 

Ok guys, i replaced the switch yesterday. It was not so hard except the limited space to work. It was kinda narrow and hard to reach to the switch but anyway. Now as soon as i touch the brakes, the stop lights come on.

Now here is the result. It solved half of the problem. Since yesterday i drove almost 30 miles. This time only ESP light comes on and stays on. ABS light has been fixed and i does not comes back on after i replaced the switch. When ESP light comes on, i tried to push ESP button however nothing happens. Light stays in until i shut off the engine. ESP light does not come on all the time or it does not come on right away when i stared the engine.

I have not check for the codes after i changed the switch. Probably I will get my VAGcom this week. I will check the modules when i get it.

Any ideas for this ESP light deal?