Had the car a week A4 Auto, Avant, 1.9TDI SE, my dad has owned it for 8 years full Audi service etc etc mint through out never been thrashed etc etc.

ESP light came on for my dad a month or so ago but went out, since then it has come on a lot but gone off no noticeable issues.

Last night it went mad and flashed a lot and the car slowed down as if it was controlling it?

Put my foot on the brake and the ABS went off briefly (as if speed sensor fault) the vibration stopped and the ESP light stayed on without flashing.

Car drove fine for the rest of the trip home no more lights, no abs or light, nothing just solid ESP light.

 

Scanned it today with code reader and I have 01826 Steering angle sensor, only a cheap code reader so I can go deeper but no other faults/codes.

Also checked the wheel speed sensors, in particular the ns front which my dad said had loads of crud pressure washed from it just before he first saw the light a few months ago. Nothing, all clean.

Light came back on and off on the 5 mile trip home?

When light is out it does appear that it comes on more regularly when going left rather than right, also picked up on the net somewhere that if the battery goes flat it can set off the Steering angle sensor?

Cruise control works fine as well.

 

Help and input greatly appreciated, got tools and years of spannering behind me just dont want to go off in the wrong direction :)

 

I had a similar issue with my A8 D3, the light would come on after the car had been running a while. I noticed it did this less in summer than winter. The Audi dealer had a look but could find nothing. I also noted that the heated rear screen stopped working.
 

Anyway, just before I sold it I put the car into a local independent garage and they suggested the reason was the alternator in combination with the battery computer. Sounded like mumbo jumbo to me. I decided to have the suggested work done, which was to change the alternator and if that didn't work to change the battery computer. They changed the alternator and hey presto the problem was solved.

 

I had researched this problem for a while and found nothing on any of the forums, some suggested wheel sensors or brake light sensor or steering sensor so I guess this problem could be associated with other issues. so I am not suggesting this is the only reason for the light to come on or the only cure. But it does show up the short comings of the main dealer.

 

Hope this helps

I had a similar issue with my A8 D3, the light would come on after the car had been running a while. I noticed it did this less in summer than winter. The Audi dealer had a look but could find nothing. I also noted that the heated rear screen stopped working.

 

Anyway, just before I sold it I put the car into a local independent garage and they suggested the reason was the alternator in combination with the battery computer. Sounded like mumbo jumbo to me. I decided to have the suggested work done, which was to change the alternator and if that didn't work to change the battery computer. They changed the alternator and hey presto the problem was solved.

 

I had researched this problem for a while and found nothing on any of the forums, some suggested wheel sensors or brake light sensor or steering sensor so I guess this problem could be associated with other issues. so I am not suggesting this is the only reason for the light to come on or the only cure. But it does show up the short comings of the main dealer.

 

Hope this helps

 

Interesting that the alternator could cause the ESP light to come on!