I have a 2004 TT 1.8T Quattro Roadster. I just had a timing belt kit put in and the head serviced due to my timing belt breaking at only 60k miles. I just got it back and it seems to be running fine, but the morning after I got it home from the shop, the Engine light came on.

I used 2 different computers, one with an older version of VagCom and one with the new VCDS software (both have worked to read codes on this car before) and both test communication OK, but when I attempt to check the 01 Engine codes I get "No response from controller". My mechanic tried with his hand held scanner (that has also worked on my car before) and gets the same issue now. Communication tests good, but no response when scanning for codes.

One other thing to note is before this incident I was having trouble with the door locks, power top controls, power trunk release and power gas cap release not working. I thought that had something to do with a command module located behind the seats/under the compartment where the top folds down, but I never got a chance to troubleshoot it.

After I got the timing belt/head fixed, now the locks and power controls are all working perfectly.

I am wondering what would cause the ECU to stop communicating like that. Loose ground or short somewhere that occurred during the mechanical work? Or maybe something related to the power controls not working, then suddenly fixing themselves?

If anyone has had a similar problem or can offer any advice, please help.

 

I disconnected the battery to get the check engine light to turn off. I found a fuel vapor tube that was not connected and connected it. The engine light has not come back on, but I still can not get my laptop with VagCom or a code scanner to communicate with the controller. I can communicate with a 2004 Toureg, with both my laptop and my mechanics handheld code scanner so they are both working.