RS4 B7 EPC and traction control light on...limp mode.

[Buller123]

Was sitting at traffic lights this morning and the EPC and traction control lights came on and stayed on. Restarting the car they were still on. Car is now in limp mode and have a 400 mile drive in a weeks time. Any idea what this could be?The engine was de-coked in January so have ruled this out.

[Surrey Sam]

Did you sort the misfire?

I'd suggest getting the fault codes read, as there could be more than one problem.

[Buller123]

The misfire was sorted filled car with 99 octane and has not misfired since so must have been that fuel. Was running like a dream even this morning then that happened just standing still. Looks like a trip to the garage in the week then ha!

[Surrey Sam]

That's handy, although a good quality re-map shouldn't have you sailing that close to the wind with 95 RON. It might be that a sensor is failing and thus struggling to keep things within tolerance when using the lower rated fuels?

So still get it the fault codes read, as you could be looking at a failing MAF or Throttle position sensor and the codes will help you with what direction you need to look.

[Buller123]

Possibly could have been a failing sensor first time around and has fully gone now?First thoughts were MAF as have had this on other cars before so not too much to worry about. Cheers for the help will get a diagnostic this week and hopefully sorted!

[Surrey Sam]

Yes that's quite possible. Be sure to get a print out of the fault codes and then post them back on here for people to try help out

[denis.dasilva2]

That happened w my car while ago and when i checked it was a leak on the SC hose and my MAF wasn't working properly
lk

[Buller123]

What is the SC hose?where is that located?will be taking it for a diagnostic in next couple of days also.

[Buller123]

Update....decided to have a look myself...opened air box...checked vac hoses...removed sensor cables fiddled around....was still up...disconnected the battery left for 30 mins...reconnected turned throttle to on position but did not ignite to try reset throttle body position. Car fired up EPC light disappeared then traction control disappeared as I pulled away. Have stayed off...any thoughts on this?

[rs user]

dont mess around with it-get codes read,go from there
arsing about will just fire multiple codes and muddy the waters so to speak..

[Buller123]

Been for a good drive and gave it a bit of a thrashing nothing has come back up so hopefully it stays that way for the drive back home in a week take it to the garage I got it from then they can sort it.

[Covkiller]

I had the same problem. It was intermittent at first then happened more often. I found it was the throttle body. Bought a new one from Audi, over £1k but resolved the problem.