Greg66

Got into my A8 (1999 2000 spec 4.2q, not chipped), turned the key, reversed 10 metres and the engine died. Then I noticed that the EPC, ABS and ESP lights were still lit up in yellow, as well as one that isn't in the manual (yellow, looks like the outline of an engine, at about 2pm on the speedo). Also had all of PRND54321 lit up in red on the dash. After a few goes at restarts, the problem reduced itself to this:

I could turn the ignition on and get the enginne turning over most of the time. Every time I did, the EPC, ABS and ESP lights stayed on. The throttle pedal was useless - you could blip it or floor it in N or P and the engine revs (and note) stayed around idle. However, it was not an even idle - the engine note was bouncing around all by itself. If i put it in D or R, the engine would either stall or continue to run at an idle, and if so, then the car would move running on around 1000 rpm. The throttle was still useless, so you couldn't go much faster than a brisk walk, and what control you had over the speed of the car all came from the brake.

Roadside assistance disconnected the battery to try to reset the ECU (or EPU?), to no avail. So, the car got towed to the nearest garage where it will get looked at on Monday.

Anyone else had a similar experience? Anyone like to venture an idea of the cost of fixing it (or even the chances of it being fixed?). The car's done 27000 miles and just outside the extended 3 year warranty period. Annual service was two weeks ago (but I guess if a chip blows, it's almost always going to blow without much warning).

April

Sounds like electrical in nature. Maybe just sensor or vital connector.

D3AeighT

Was your gas level very low? If it was, the car will not even turn over and act like it is dead electronically.

PaulW

Sounds like some kind of "limp home" mode, the computer will most likely tell you what's wrong.

gtrucinski

Gregg:

I had a similar problem. The trans is in fault mode when all indicators light up. I had a short in the wiring harness between the TCM under the hood (Beside the Motronic) and the control module on the drivers bottom side of the trans. Audi couldn't identify the wiring harness....ZF who makes the trans was lost. It took two weeks to find and fix along with a labor bill of $800 to cover removing the harness, repairing the lead and re-installing. Good luck and let us know the results.

Gary

Greg66

Well, today has not been much fine. It seems that the box in which the ECU and a lot of other toys sit was full to the brim with rainwater (I'm getting this second hand from the garage at the moment - I haven't been to see the car yet). I'm told that a lot of the connections were corroded, suggesting that water ingress has been a problem for a while.

Bottom line - new ECU and associated box of toys -fitted (it's a 17 hour job according yo the dealer) - GBP 3330.

Dealer's quite confident of getting a goodwill contribution from Audi UK (the car's 3 1/2 yrs old), but the amount's up in the air at the moment.

Merry Xmas :-(

PaulW

The ECU is under the bonnet (as somebody in the UK might say) on the right (maybe not on a RH drive car, don't know).

Here's a picture of my US spec ECU and TCU:

<img src="http://pictureposter.audiworld.com/22012/dsc03713.jpg">

As you can see, it sits in a plastic holder that has a gaket on the cover to keep out foreign material and water. Somehow your gasket leaked by, maybe you also had leaves in the side like I do!

Make sure you determine the cause for the ECU getting wet before fixing the problem (i.e. why did the water leak in).

I wouldn't change a thing. A wiring harness and ECU (how about the TCU, transmission control unit), did they say that went bad too? I would have to go back, but I think the ECU is the black thing, the TCU is the vertical box right next to it, but it might be the box sitting horizontial.

Your box didn't fill up with water overnight, it had standing water in it for months or probably a year or more.

Disconnect and remove the TCU and ECU, dry them out with a heat gun or the sort, the same with the box and the electrical components, hook them back up, and see if your car works.

Probably would take me 1-2 hours to complete, so figure 10 hours for a dealer (that's a joke, I just hate dealers).

If your car starts up and works, then live with it. It probably will be just fine. Think about it, it was working until just a few days ago with water in it, if you remove all the water, it will probably start working again!

Hope this helps, I bet it will!

pw

Greg66

PaulW - thanks for the info - did you just happen to have a pic to hand, or did you start taking your car apart?!

As I said, I haven't seen the problem yet - I've just had the garage relate what they found. I think the TCU may be OK, as they told me that they had someone in two weeks ago with the same problem, but his was worse as his transmission was shagged to boot.

I think I will insist on the drying out option first. However, the garage told me that all of the connections have corroded to buggery, so I'll have to wait and see whether it works once it's dried out.

As you say, the cause is the key. I intend to make sure I'm satisfied that the cause of the leak is identified and remedied.

I'll keep you posted.

PaulW

Actually, I took it a long time ago when doing the H&amp;R's, we were talking about ECU and TCU numbers. It was actually on my picture poster from Audiworld, didn't even have to upload it!

Even though the connections are corroded, it's worth a try to clean them up with contact cleaner and hook them up again.

Car electrical components are amazing at how durable they are! Bosch components are even better. I'll bet 2 to 1 that it works without a $10,000 repair.

pw

Greg66

Well... when the car arrived at the dealer, the diagnostic comp reported 38 independent faults (don't know which ones; just had the number fired at me). I asked them to point a heater (which I supplied at the offending area for the afternoon; they left it on overnight as well. Next day the diag comp reported 36 independent faults. I don't think drying out is going to do the trick ... :-(

On reflection, the problem might have been exacerbated by some advice given by the roadside recovery guy who came out to me. At this stage, neither of us had a clue as to the cause of the problem (water); the best guess was a faulty ECU or connection to it. He suggested letting the engine idle so that I could still listen to the radio and keep the heating running until a flatbed transporter arrived (which took about an hour). Knowing what I do now, it probably wasn't such a smart idea to continue to run current through electrical components that were submerged.

Audi GB have indicated that they are prepared to contribute to the costs of the fix - negotiations on the "how much" commence tomorrow.

Whatever the outcome, I won't see the car this side of early Jan; the upside to this is that a mate is lending me his S8 over New Year while he's off to NYC on Concorde. Some people...!