G2Mike04

Good idea...didn't think to try that. Ok, cleared all the codes that the auto scan gave and then took the car for a short drive. Still clunked around a bit when cruising between 35-40 or so. Ran the auto scan again after the drive and no fault codes were found. Here's the printout:


-------------------------------------------------------------------------------Address 01: Engine Controller: 4D0 907 551 AH Component: 2.8L V6/5V MOTR AT D01 Coding: 06251 Shop #: WSC 06325 No fault code found. Readiness: 0000 1101
-------------------------------------------------------------------------------Address 02: Auto Trans Controller: 8D0 927 156 BQ Component: AG5 01V 2.8l5V USA 8511 Coding: 00000 Shop #: WSC 00000 No fault code found.
-------------------------------------------------------------------------------Address 03: ABS Brakes Controller: 8E0 614 111 M Component: ABS/EDS 5.3 QUATTRO D31 Coding: 0273004134 Shop #: BB 24302 No fault code found.
-------------------------------------------------------------------------------Skipping Address 15-Airbags
--------------------------------------------------------------------------------------------------------------------------------------------------------------Address 17: Instruments Controller: 8D0 919 930 LX Component: B5-KOMBIINSTR. VDO D10 Coding: 06262 Shop #: WSC 40829 No fault code found.
-------------------------------------------------------------------------------Address 35: Centr. Locks Controller: 8L0 862 257 N Component: CV-Pump D05 Coding: 16140 Shop #: WSC 06325 No fault code found.
-------------------------------------------------------------------------------Address 45: Inter. Monitor Controller: 4B0 951 173 Component: Innenraumueberw. D03 Coding: 00102 Shop #: WSC 06325 No fault code found.
-------------------------------------------------------------------------------Address 56: Radio Controller: 4B0 035 186 Component: Radio D01 Coding: 00201 Shop #: WSC 00000 No fault code found.
End --------------------------------------------------------------------------------------------------


Btw, I have noticed that the issue sometimes DOES continue to occur even if you take control of the trans using the tiptronic or just dropping straight down into 4th.

As we speak I am using the control module finder feature to see if there are any existing modules the auto scan didn't try...I'm not sure how many there are supposed to be. If there are any, I will check them for fault codes and post again.

In the meantime, any ideas?

Pete@ECSTuning

Moisture in the TCU?

G2Mike04

Hmm...the TCU is under the footwell on the passenger side in the front. The only moisture issues I had were in front of/around the firewall. Here's what I'm thinking:

The torque converter's lockdown clutch is not behaving appropriately. The issue occurs during times when one would expect it to be engaging (coasting or light throttling between 35-45 mph). Why? Could be a number of things. Could be that the incorrect ATF is in there (I noticed that it's red, not light brown/yellow like I've read the audi stuff is.) Could be that it's wearing out. Could be that the TCU is not controlling it appropriately.

At any rate, I'd like to figure out whether that's the problem. Does anybody know whether there's a way to program the TCU to just never engage it? Could I just disconnect its control circuit manually? I figured out that checking measuring blocks group 007 in the TCU module allows you to monitor the clutch's activity.

4Driver4

This post makes it sound like you did not physically check the TCU. You need to pull up the carpet and open the box. Do not skip this step.

G2Mike04

Just checked the TCU. Box and unit are bone dry, and there are no signs of water having gotten in there before now. The carpet and foam are dry as well.

4Driver4

That's good...or bad. If it was wet at least you would have had a diagnosis.

G2Mike04

My thoughts exactly. More bad news...I wanted to try monitoring measuring blocks group 007 (the lockdown clutch) while driving to see if it was indeed oscillating but the TCU stops communicating when you shift out of park.

Now the question is whether should I just suck it up and hope the tranny is not slowly destroying itself due to that fluid or drop the money on the fluid change and see if that makes any difference. If it turns out that the tranny or torque converter is just screwed, the fluid change will have been a big waste.

Decisions decisions decisions...