new to this forum. i have a 2001 A6 4.2 and i jest rebuilt the transmission cost me $2900 bench build . but its still going in to limp mode, the man at the shop seas its the ecu, can that be true can it have water damage. need help

 

or 29oo$ it better be working right. have him double check his work

 

He could have done anything to the transmission good or bad and if the TCU is the problem it would stay in limp mode, so it's not going to be his fault at all (except for not checking on it).

Water damage may be present in the rear passenger floorwell where the TCU is located (semantically the ECU doesn't deal with the transmission too much and that's why you want the Transmission Control Unit....not engine)

 

I'm just sayin that if its not tip top he should go back over everything to rule it completely out then you can tackle the tcu

 

What was the reason to get the transmission rebuild at first place?
What were the DTC then?
What are the DTC now?
Who's idea was to rebuild the transmission?
Who took the transmission it out - in?

As one could see the answers lead to clarification of the responsibility and warranty here.
Bouncing between rebuilder, TCM, installer would easily become a nightmare.
The only way to proof rebuild is ok is to swap your TCM with clean one;
Or to swap your TCM on a car with fine transmission.

BTW - the TSM should be under front passengers carpet

Is the torque converter replaced?

 

bought the car from a friend hit in the front minimal damage. fix that the test drove and drove. drove fin cold but wen it wormed up the tranny started slipping in and out of gear. took it off and had a bench biuled
$2900. put it on and same problem. dove fin then wen it got normal temp it starts slipping. take the car to the shop and they say its the valve body. they put a new one. and now all i get is limp mode nothing ells and revers. they scanned it and got codes P1748,17927,17978, need help on Wat to do Wat to check thanks located in Denver co.

 

17927
P1519
Intake Camshaft Contr.,Bank1 Malfunction


17978
P1570
Contr.Module Locked
Engine Control Module (ECM) - immobilizer active
Probable causes:- Incorrect/damaged key, incorrectly coded, ECM/immobilizer replacement without recoding, wiring, immobilizer defective.
http://wiki.ross-tech.com/index.php/17978/P1570

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Not much of a sense for me (in your case).

Did you witness the code retrival?
What is the color, brand of ATF?

Who's idea was to get the transmission rebuild?

 

it was may idea. thought that was the problem sins it was slipping out of gear. checked the tcu and ecu for water damage but every thing looks good no water. plugs look new. any advice on Wat to do. any offers on the car. my be taking it to the dealer to see Wat they think. need this fix asap been down for to long.

 

any on located in denver so i can tray there tcu will pay $$$$$$.

 

When the front end has been repaired - the transmission cooling lines have to be disconnected - then the ATF level adjusted.
Slippage could be caused by low ATF, improper ATF, the pressure is not enough to activate the internals - TCM senses delay and limp mode results - dashboard lights all gears.
I see no codes related to the transmission.
Other codes might indicate that the front-end damage was not this light.

Bring the car to a reputable shop - German cars. Let them diagnose it. Fluid level.

Do not be in a hurry, as you'll spend much $$$$ for wrong things.

Does the transmission behaves the same as it behaves before rebuild and valve body change?
How much did you pay for the valve body?
Do you keep the old one?