Possible failure of ECU- anyone experience this?

[papadoc]

10 days ago had just started my car, drove about a block, sitting at stop light and it just dies. Cannot restart, turns over but nothing happens. Battery, gas etc. fine. Wait 30 minutes for tow, he tries to start car (as if I am a dummy) and it starts for about 5 seconds and dies again. At my indy shop, same thing; brief start, then dies. They suspect ECU and pull the whole thing to ship back to APR. They replaced their chip, though their diagnostic did not indicate a problem but they thought perhaps it had loosened and said they upgraded the chip at the same time (though I have had it since they first came out with it, did not realize they had an upgrade). Back in the shop, same thing :-(. Car starts, runs fine, and as soon as it starts to warm up, it dies. Won't restart until it sits and cools off for a while. APR and Audi Tech Services are stumped but agree that it is probably something in the motherboard of the ECU with a failure that kicks in once the warm up cycle is finishing. It's a cool $1154 for a new ECU, which then has to go with the car via tow to dealer to inactivate the immobilizer codes, then pray it starts and hope to ship back to APR again.
We have a saying in medicine, one never wants to be an interesting patient. Now I have an interesting problem with my car. Anyone else run into such a thing, or does anything hear ring some distant bells before we head in the wrong direction?

[na1mt]

Sounds like a crank/cam positioning sensor

[Elevens]

Sounds like a crank/cam positioning sensor

Agreed! I had a 93V8 Quattro with the 4.2L engine. It had a same problem as Papadoc, It wound up being the Crank Position Sensor. So I would say that's a good call. Hope you get it resolved..................

[10SecS4]

When the car is failing to start, which lights do you see illuminated on the cluster when you turn the key to the right without attempting to start it? If the CEL and EPC lights are on, I doubt it's the ECU.

I'm assuming you've checked the ECU for DTCs and there either were none or none that apply to your issue?

[LIRS6]

10 days ago had just started my car, drove about a block, sitting at stop light and it just dies. Cannot restart, turns over but nothing happens. Battery, gas etc. fine. Wait 30 minutes for tow, he tries to start car (as if I am a dummy) and it starts for about 5 seconds and dies again. At my indy shop, same thing; brief start, then dies.

I experienced this same behavior within the first year of owning my car (bought new) - when I described the circumstances to the dealer ... each time, start-up okay when cold, then kaput after warm-up .. the dealer spoke with Audi in Germany ; the recommendation was to replace the wiring harness, which they did. Cured the issue.

Oh, and yes - same experience with the tow operator!

[as350]

Sounds like the crank position sensor. Other Audis that are of similar vintage are starting to run into almost identical failures and replacing the sensor cures the engine failures.

[kevin]

We had a car in the shop a year or so ago with an APR tune. It ended up someone had inadvertently enabled the immobilizer that came with the APR tune via the switching system they use on the turn signal stalk.

[papadoc]

Very much appreciate the input and good wishes. I have great faith in the guys in the shop I use, and have relayed this information on to them. Awaiting word back. Getting a bit tired lugging around in a big old Yukon XL...

[lswing]

Very much appreciate the input and good wishes. I have great faith in the guys in the shop I use, and have relayed this information on to them. Awaiting word back. Getting a bit tired lugging around in a big old Yukon XL...

Why not drive the Bugatti?

[ttboost]

His neighbor won't let him anymore...

[papadoc]

Why not drive the Bugatti?

Would if I could! Believe me though, that is not one to use as a daily driver...

[na1mt]

Update???

[papadoc]

Had to wait for the crank position sensor to arrive, not available locally, should be installed tomorrow. Hoping that this does it!

[papadoc]

Groan. Replaced the crank position sensor, no change. The car starts in the morning and runs fine until the warm up cycle is complete and then dies. Won't restart until cold again. I don't want to have them replace the entire ECU at $1200 unless I really know that will do it, but wow, this is frustrating...I've suggested as noted above that they call Audi in Europe. Still in the Yukon...

[10SecS4]

Did you check for boost leaks?

[papadoc]

Did you check for boost leaks?

Don't know that they have, but again, it runs fine until it doesn't! Always after warm up. Each morning they start the car, drive it into the bay, and it dies. No codes either. Possibly going the route of our colleague on Long Island next.

[10SecS4]

A boost leak on a mass air equipped car like the RS6 can result in the condition you're describing. Do you smell fuel at all either while you're cranking it or as it's running before it dies?

[ttboost]

Coolant temp sensor?