Sorry, I am not really knowledgeable about automatic transmissions (stick to stick yet), I bought a car for my sister (2004 passat 1.8T 5-speed tiptronic) and did not notice the weird problem with the tranny during the test-drive.
The problem is that there is a hard shift from 5th to 4th gear when you are slowing down.
I know it is exactly 5-4 because I move the lever to +/- mode and see the 5th gear on the dash display. Then you just slow down until the tranny decides to down shift and it makes it pretty hard so that you feel it as a push. 4-3 and 3-2 shifts are OK. Note, if I drive on the 5th gear in +/- mode, then kick down with manual downshift then the 5-4 switch is smooth, it only happens when you are not touching the accelerator.
When I have read the codes via VAG-COM, I got this for the tranny module:
Control Module Part Number: 3B0 927 156 AM
Component and/or Version: AG5 01V 1.8l5VT USA 1212
Software Coding: 0001004
Work Shop Code: WSC 05311
1 Fault Found:
17095 - Transmission Fluid Temp Sensor (G93): Implausible Signal
P0711 - 003 - Mechanical Failure - Intermittent
I searched thru the forums and some people said it might be a low ATF level. I checked and added ATF (properly), cleared the codes, but the code came back.
Do i need to replace the wiring harness as ELSA recommends in case of a non-working temp sensor?
I doubt it will solve the problem of 5-4 hardshift though.
Any good advice, guys?