4Driver4

Lately my 99 A6 has been shifting oddly sometimes. Usually a restart cures things, but I knew I would have to investigate at some point. Yesterday my CEL came on and the trans was in limp mode. VAG-COM found an ECU fault saying that communication with the TCU was lost. VAG-COM could not communicate with the TCU.

I pulled the box that contains the TCU out of the passenger's footwell to find it partially full of water. Not good. No other water present in the footwell. Very odd. Looks like someone left a window down at some point and the water has been in the box for a while.

Anyone ever see anything like this?

myfirstimport

Hornfrogs are amphibians and should be able to swim naturally.

4Driver4

Hornfrogs lack some of the functionality required to run my transmission.

myfirstimport

<ul><li><a href="http://gofrogs.collegesports.com/">http://gofrogs.collegesports.com/</a></li></ul>

4.2bandit

If you have ever had a windshield replaced I bet the cowl trim is installed wrong

6ULDV8

Yes, windsheild leak.

WildBlueYonder

Apparently, there is a drain hole in the battery tray (under the battery?) which is easily clogged with leaves and other debris. Seems it is nearest the passenger footwell and that is where any overflow is likely to go. If it was a window, I'd expect you would see some water staining on the interior materials.

Good luck...

greg1983

Hi I have found a 99 a6 2.8 quattro for sale for 1500 but the guy says the trans is stuck in limp home mode. he says the tcm got wet. i have found a post where you had a similar problem. did you get yours fixed and if so what was the solution? send response to prostyle123@gmail.com because i only registered on this website to ask you this question.

thanks
greg

4Driver4

Usually they dry out and all is well. You'll have to remove the tcu, take the cover off and let it sit for a few days. Common issue.

greg1983

Okay he said he said the conector going into the module is corroded also. couldn't i just cut one off a junk car and wire it in with solder and heat shrink. or is it easy to replace the hole harness going to eat.