EPC ESP WTF

[Audi Pardner]

Ok guys, I've searched the forum and can't find any info on the symptoms my car is suffering from so wonder if any of you can help please.

Just coming through a village on the way home and took a tight bend on a slight incline at about 30 (nothing dramatic, no sliding about or bogging down). The car lost power/went into limp mode and I noticed the ESP and EPC lights were on (permanently). Drove about 2 miles with no change, so stopped, cut the engine, and on re-start the warning lights were off and it drove fine. Got home (another mile or so) and after switching off the engine to open the garage door, the warning lights were back on upon starting the car again. All the owner's manual tells me is I need to take the car to a dealer to get shafted

If anyone has had these symptoms and/or knows how to sort it, please let me know. I'm supposed to be using it tomorrow

[MikeFish]

VCDS is your friend here. Without the help of a scan it could be a million things. Do you have access or anyone nearby to help out? Where in the country are you?

[adsgreen]

Even normal obd scanner better than nothing

[Audi Pardner]

Thanks guys. I've got VCDS but, as a lazy ******* and useless with anything vaguely IT related, I've not got round to registering it and downloading, so this is obviously the right time to get my **** in gear.

That said, I'll probably be back here shortly asking about codes and how to use the thing

[pDkALO]

As previous comments, nigh on impossible to tell what it is without diagnostics, however, a tip if I may...

Once you get to grips with VCDS and do a scan, unless you're absolutely 100% sure that you get to the bottom of what the problem is and know what needs to be done to fix it, I strongly recommend that you do not clear the error codes yourself thru VCDS. The problem may not come back for a while and then you're snookered if you want to trace and fix whatever the issue was, because dealers will all need to see the fault in the diagnostics log, which they won't be able to do if you've cleared them.

Good luck

[Audi Pardner]

Many thanks Dalo.

OK chaps, a quick update. I managed to install VCDS on my laptop OK (much to my surprise ) and ran a scan. It identified one fault - 'accelerator position sensor (G79) (G189). 'Implausible correlation - intermittent'. Took the car out and it ran fine; no EPC or ESP lights.

So I'm guessing the throttle sensor is probably (intermittently) faulty. Does that sound about right? If so, as the car has to go into the stealers next Saturday for a new wing (warranty job ) and a service, I'll get them to replace it, unless anyone suggests something else.

Thanks

[adsgreen]

If it works like other systems I have used, then the pedal is two sensors set out of phase to each other.
So one goes from 100% to 0% and the other 0% to 100%. Thus they operate as a check on each other as the ecu knows it can read either signal but both should add up to 100% at all positions. Anything else and there's a fault code thrown and the car will go into a big limp home mode.
What you really needed was the full error log details from VCDS which would tell things about the error count and such like.

Now they are cleared simply keep an eye on.

[Audi Pardner]

Thanks Ads. It cleared yesterday just after it happened when I cut the engine and restarted, them went into limp mode again and was fine today, so I'll monitor it and retrieve the full readout on VCDS and see what it says.

[tmg]

so the v8 rs4 engine is closely related to the one in my s6 (well the other way round but hey) - here's what happened to me with that throttle angle sensor thing.

also as per ads, you can take the pedal assembly out (its 3 torx iirc) and then open and clean the angle sensor pod, but I believe the throttle angle sensor usually refers to the throttle body rather than the pedal itself

viewtopic.php?f=44&t=106255

[adsgreen]

It could be the the throttle position sensor.

Easy enough to log in VCDS

Also I think a typo in op:
Sensor g79 and g185 (not 189)

[adsgreen]

Check for water in connections too

[Audi Pardner]

Yep, you're right Ads, 185. I'll take a look at the pedal assembly

[adsgreen]

Just checked ElsaWin
G79 - Accelerator position sender
G185 - Accelerator position sender 2

Both from the pedal box setup - so a mismatch between the two and not the throttle angle sensor in the engine.

[Audi Pardner]

Thanks again Ads