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Discussion Starter · #1 ·
I just noticed this issue the other day for the first time... When the car goes from 4th to 5th gear and there is not a full load (i.e. full pedal applied) and the speed is about 40MPH, it appears that the transmission wants to briefly switch back to 4th gear very briefly then back into 5th... it does not last long (maybe a 1/4 second) and is barely undetectable. I notice that the engine RPM jumps up slightly when it happens. It can happen one a second or so. My first thought was to check the TCM to see if the unit had any water at all in the plastic housing, since I recently also noticed that the passenger rear floor area is wet after rain. The module box and floor cavity it is in were perfectly dry. I disconnected the haness connector and all of the pins look fine. I now have the TCM sitting on top of the carpet instead of under it. I tore into the passenger rear door and there was a breach at the bottom of the window regulator that was letting the water in. Anyway, I have a call into the transmission place I use for fluid changes and have not heard back from them yet. I'm posting here to see if anyone else has had the same or similar issue, and if there is anything else I should be checking (modulator, etc...). In TIP mode there is no problem in 4th or 5th gear.
 

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PassatWorld Elder
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27,961 Posts
The torque converter will lock up at 40mph in 4th until the throttle is pressed enough to unlock it. That would cause the rpm to go up and then down when it locks again. I used Tip mode primarily as I got better mpg with it. You can also program the trans for sport mode via VCDS. My torque converter started to fail and allow the rpm to climb under throttle even in tip mode, so I eventually replaced it.
 

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Discussion Starter · #3 ·
@PZ, I just read the entire thread on your TC replacement. I do have a VCDS. What do I need to do in order to monitor the TC lockup and slippage? What would sport mode do for me in this situation?
 

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PassatWorld Elder
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This is from my original scan, so go into Auto Trans. I don't remember the measuring blocks, but we were able to see trans temp and clutch locking or unlocking. Sport mode will allow faster downshifts at less throttle and will hold gears longer. It's more responsive overall. It may reduce the trans shifting down constantly, but it won't stop a slipping TC.

Address 02: Auto Trans Labels: 8D0-927-156.lbl
Part No: 8D0 927 156 AT
Component: AG5 01V 2.8l5V USA 3132
Coding: 00102
Shop #: WSC 05311

1 Fault Found:
17125 - Torque Converter Clutch: Stuck OFF / No Power being transferred
P0741 - 35-10 - - - Intermittent
 
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