Transmission unresponsive after LIMP mode..... P1850

[sbcrc86]

I was doing a bit of spirited driving in the rain, hit a bump in the street and transmission went into limp mode. I pulled over restarted the car and LIMP mode was gone but vehicle is unresponsive when shifted into gear. After getting towed I hooked up VCDS and it shows the transmission storing code:
Powertrain Data Bus
P1850-003 Missing message from ECU- Intermittent

Honestly the transmission feels like a pressure valve is not allowing for proper flow of trans fluid, the only thing I noticed that may be wrong when I was monitoring data is that the input speed on the transmission is reading ZERO at idle, is this normal? Does anybody know of any relays or fuses that should be checked or of failures known to have these symptoms.

[lswing]

Sounds like it's unplugged from the TCU? Check trans connection at trans body, check TCU under passenger floor mat.

[sbcrc86]

I checked both and have even dropped transmission pan to inspect for disconnected electrical connections inside the transmission for issues or damaged internals and everything looks good. TCU is perfectly dry and shows no signs it was ever wet.

[TozoM8]

Yes, it should be 0 rpm unless the car is moving.

[lswing]

Yes, it should be 0 rpm unless the car is moving.

You're back! Trans is doing great, and I'm not beating the crap out of it :revs::incar:

[lswing]

This was your fix right, loose/broken wire to ECU? http://www.rs6.com/showthread.php/31650-Oxygen-Sensor-B1S2-broken-wire-in-harness-or-bad-ECU-help-!

[sbcrc86]

That was the fix for a downstream O2 sensor that was unresponsive. This new issue does not seem to be so easy. Its as if when LIMP mode was triggered it corrupted a data dump in ECU or TCU. The question now is which one is damaged. Does anybody have the pinout for the TCU?

[sbcrc86]

Honestly these PIA transmission problems have me taking a hard look at 01E.

[lswing]

Honestly these PIA transmission problems have me taking a hard look at 01E.

Your auto trans problem sounds unique though, first I've heard of, wiring would be a great fix. Mine just have the problem of breaking internally...

[MaxRS6]

...Mine just have the problem of breaking internally...

+1- I got the shaft with the shaft break last time. All of the king's wiring men could not put Humpty back together...Ooofff

http://i827.photobucket.com/albums/zz195/MaxRS6/rs6%20Trans%20Shaft/IMG_20141108_080426_269_zpse1685426.jpg
http://i827.photobucket.com/albums/zz195/MaxRS6/rs6%20Trans%20Shaft/IMG_20141108_080512_615_zps3e06408a.jpg

[sbcrc86]

I have a feeling that may be what's wrong with mine

[marklar182]

There is a good trans out of my totaled car in the classifieds.

[sbcrc86]

I replaced my trans a little over a year ago with a brand new unit from audi so it's supposed to be under warrantee. I'll get the replacement and sell it to fund 01e swap.

[sbcrc86]

15742Here is the issue, sheered off input shaft.

[Zorb]

Here is the issue, sheered off input shaft.


Look at that break. That's defective! Improper manufacture. That part was brittle from day one, destined to break exactly as it did.

[lswing]

Crap, at least you found it. Not sure if it wasn't just stress over time. It's only 11 years old after all. What's your mileage for reference, and tuned at all for xxx miles?

[sbcrc86]

My mileage is 109k but I replaced the transmission with a 4500 unit from the dealer. 01E has been initiated, have the adapter kit ordered. After seeing the failure there is no way I am installing another ZF in the car.

[sbcrc86]

Stage 2 unitronic putting 430whp and 493ftlb@wheels.

[lswing]

I'd be reading the thread and chatting with the fellow who can't get his manual swap registered in MA. ZF's can easily last 100k, it's just a matter of getting a good one, care, and how much it gets beat on. Again, if you're stock or on a more moderate tune the life expectancy will be much improved...that and reduction of WOT takeoff and shifting:):addict:

[lswing]

Stage 2 unitronic putting 430whp and 493ftlb@wheels.

Now it all makes sense...nice numbers!

[sbcrc86]

Thanks, the tune and city driving conditions definatley put a load on the transmission. Can send me a link to the thread about Mass reg.

[lswing]

He's got a few threads going, it's been a mess it sounds like. http://www.rs6.com/showthread.php/31758-Does-anyone-here-have-a-6-speed-car-registered-in-California

[sbcrc86]

Mass has recently gotten strict but as long as your ecu doesn't have emission monitors altered you would pass inspection. If people are reporting to the registry that they have altered the car then maybe you would have problems.

[EINHORN]

Thanks, the tune and city driving conditions definatley put a load on the transmission. Can send me a link to the thread about Mass reg.

He's also got one on Quattroworld in the New England Region section

[EINHORN]

Mass has recently gotten strict but as long as your ecu doesn't have emission monitors altered you would pass inspection. If people are reporting to the registry that they have altered the car then maybe you would have problems.

BTW he's saying that he didn't report anything the system did and that they match to other inspections of the same vehicle in a database

[sbcrc86]

I think he got himself in trouble by getting flagged at inspection for the tune the first time he went. I always get inspected with a stock ecu.

[lswing]

I think he got himself in trouble by getting flagged at inspection for the tune the first time he went. I always get inspected with a stock ecu.

Thats easy if you're still stock auto. My impression is he never got the ecu properly sorted after the 6-speed swap.