EPC, ABS and ESP lights: HELP!
 

ON no! :-(

All 3 of these lights came on on the way to work thi morning, coupled witha# a serious power loss.

The revs seem to go up OK, it's just that there's not much transmitted to the drive.

Anyone got any ideas?

I would suspect something to do with either the MAF or the throttle body because the EPC (Electronic Power Control) light is on. As soon as the engine ECU doesnt think it can control the power output of the engine adequately it tells the ABS/ESP to shut down just in case it cant shut off the throttle if things get out of control.

A quick VAGCOM should tell you - good luck.

Thanks Dave. Will this show up on VagCom? And, if you're right, what kind of a bill am I looking at?

Yes it will definately show up in vagcom in the engine ECU and the ABS ecu.

Price wise - give us a call or email with the faults or specifically what you need and we can take it from there.

Dont worry - I'll tell the guys to take it easy on you ... :)

I think I'm going to have to drop it in to my local Audi indy on the way home as, because this is my daily driver, I can't live without it. I'm hoping I can leave it there, get the train home, and get it back tomorrow.

Is it a quick job do you think?

It will depend what it actually is - I am only guessing here - MAF and Throttle body are quick swaps if your local place has them available. There are other things it could be so until you get the diagnostics I cant really say.

What I can say is that whilst a new MAF will be around £100, a new throttle body (if that is what your local place suggests) will be close on £1k so I wouldnt leave them a blank cheque until you find out what the problem really is. If it is the throttle body we should be able to help at a fraction of that cost.

Thanks again, Dave. If it's the throttle body, I'll give you a call and see if you can send one direct to A4 Audi

Well that was strange. Got into the car after work and the EPC light had gone out, but the other 2 (ESP and ABS) were still on, and the power was back. Got it to A4 Audi and parked it up whilst I went into reception. Andy came out a couple of minutes later with the all singing and dancing VagCom thingy - started it up - and no warning lights at all! No real clues from VagCom either.

He suspects that there may be water ingress into the connections for the throttle pedal, but, for the moment, all is well again. :)

great news Jim. The ESP and ABS together (if it happens again) could be an ABS sensor on the way out

cheers

How old is the battery Jim?

Battery first
 

I would check the battery first...check the carpets in the passenger and driver footwell that will tell you if there is water ingress...

Why the battery? Not sure how that impacts on this

Think its more of a d3 thing, but generally a battery that isn't in 1st flush of youth can start causing issues with the electronics, especially on cold start

May just have to wait for what appears an intermittent fault to become permanent before it can be diagnosed properly.

The voltage on older batteries dip below the threshold when you're cranking the engine over causing ECUs to go into panic mode and throw wobblies. Once the vehicle has been run and some charge put back into the battery the ECUs are happy again and behave again until the next time

With reference to the Battery..... it can cause all sorts of weird issues...

A few weeks back I hadn't used the S for 2 weeks and got in to start it up and all sorts of major warning lights appeared on the displays...
My first thought was that some major electronic part had popped.

A quick call to my local Audi agent and advised to jump lead another battery and all was healthy again.

Apparantly at certain levels of low charge the ECU throws up varying warnings....

Warnings disappeared
 

Hence why when you driven the car for a while everything seemed to go back to normal.

What I would do is go to your local halfords and they will do a battery test for free....if all good you can then consider other possibilities.

This doesn't sound right. I was over half an hour into my commute (mostly dual carriageway and motorway) and had covered close to 30 miles from starting when the lights came on and the power went. I restarted it when I arrived at work, and they all stayed on. Then, 8 hours later, when I started it again, the EPC light was out and power was back again. Finally, after another 20 miles or thereabouts, a restart at A4 Audi saw all the lights out.

So, not related to a cold start at all, I don't think. And cold starting isn't ever a problem.

But it's reminiscent of my wipers giving up some months ago (in almost exactly the same spot on the M8), not resuming on a restart, but working fine again at the end of the day. And no recurrence (he said with fingers crossed).

Perhaps this is Glasgow's own Bermuda Triangle?

Looks a bit like the screwdriver bit holders I have in my set (it's not one of mine :))

EPC,ABS and ESP lights
 

Hi, this is my first post although i have owned my S8 for just over 12 months and have put 25k on it since then. Needless to say having found this forum i do browse it regularly and noticed your post. I live near Cardiff and entrust all work on my car with Fairwater Garage who have installed a BRC lpg system, carried out box oil change and remedied a couple of electrical gremlins the most recent of which mirrors the problem you have. I have had 2 prior occurrences since letting Simon at Fairwater carry out diagnostic work this past week, I might add that my lights were coming on when it rained and then clearing down when things dried out. I have spoken to him briefly on the phone since getting my car back today, apparently 2 fault codes were logged: ABS and throttle potentiometer. He traced the faults to the plugs contained in the plastic box in the windscreen scuttle. The seal on the box has degraded and let moisture in resulting in corrosion to the pins of the plugs which relate to each of the fault codes. The plugs have been replaced/repaired and the box resealed. He sent me 4 photos which hopefully i can attach. It's an easy and worthwhile check for condensation under the cover which could be a clue to plug issues either present or likely in the future if moisture continues to get in.

Thanks I'll have a look and see. My garage had suggested water ingress too, but hadn't explored further as there were no fault codes and the problem went away.

BTW, if you've not already done so, introduce yourself and add your name and details to the members list.

And welcome! :)

+1 for water ingress.

If it is "botang's hole" -- google for it -- you will discover water under carpers in passenger footwell. In this case water is dripping right on ABS relay, which is located below glove box. You don't need to remove glovebox to remove that relay. If water was dripping on it the relay chasis will be full of water.

Have you been driving in rain when it happened ?

I thought it was only the PF cars that had 'botangs hole'

I fixed that hole in my FL car this year.

If you find water under passenger carpet please check your ABS relay (as well as other relays) under glovebox.