I just recently change my trans fluid (new to me 2005 Cayenne Turbo, 43K miles last year, now 53K), as preventative maintenance. Looks like it may have been changed once already since it was red (thought the OE fluid was blue)? Anyway, did 2 drains and refills, used Mobil 3309, didnt drop the pan (Ill do that in another 20K miles or so).
After the second drain and fill, it seems like it is shifting smoother (not that there was an issue before, just a hard downshift from 5th to 3rd once in a while), but is shifting different. Seems like it drops down to 1st real easy from a standing start if stepping on it pretty good (thats ok by me), and it seems to hold gear longer - shift at higher rpm (thats ok by me to), but the real difference to me is that it seems like when starting in 2nd, there might be some slipping? If accelerating hard from a stop, but not so hard it downshifts to 1st, the rpms rise as normal past 2000rpm - 2500rpm, but then it seems like they back off a bit in this range then rise again as normal, almost like a shift in 2nd (2.5 gear). I previously had a Volvo XC90 with an aisin trans that did this in 3rd gear, and its normal per owners (they all do it, kinda like a 3rd 1/2 gear), and this feels similar, but in second. if I accelerate easy, I dont notice it. I just dont recall this behavior prior to the fluid exchange.
I did reset the trans adaptations, so maybe this has something to do with it?

So, I have an Icarscan and was watching several tiptronic data streams, and the TCC slip rpm would rise to around 500 - 1000 rpm when this would happen. At idle the TTC matches rpm, or is a bit lower, and when the TC locks in higher gears, there is 0 slip. In other gears when not locked the slip seems low (< 500 rpm). I dont have a good baseline from before, as I never looked at these value prior to the fluid change.
Maybe my tranny is now operating like it should, with fresh fluid, and Im just not used to it?

Does anyone know what the max TCC slip speed should be, is this normal behavior in 2nd gear I am describing? Can someone read theirs and see what they get with a scan tool?
Ive searched the internet and havent found much.

Im thinking of doing one more drain and flush, which in the previous 2 has gotten me about 5.5 - 6 liters changed out, again with mobil 3309. Maybe first I will recheck the fluid level (and yes, I followed the correct procedure, about 3 lto 4 liters in after draining, then start the engine, use my icarscan to read trans temp, keep adding till overflowing around 35 to 40c, both times with the drain and fills, and put back in what I drained out exactly. Shifted through all gears several times when refilling prior to reaching temp. One thing I havent done after either drain and refill is to check the level after driving it for some time, but since I measured the fluid that came out, and put back in the same, and followed the fill procedure, I figured I was good. If anything, per the recommendations I have found on forums that its better to be a bit overfilled then underfilled, I shot for closer to 38C and a decent thin stream running out the fill hole (not just drops) then capped it off, so maybe I am overfilled?

Thanks in advance

 

Hi,

Did you solve the issue? I have the same issue on my 2012 Panamera Turbo? Changed the oil and now seems to rev to 2000 RPM before changing to 3rd gear, not normal, also revs high before engaging in reverse gear.
Any help would be greatly appreciated.

Cheers

Lee

 

I rechecked the level at the right temp again, fluid came running out, so ok if a bit overfilled.
i think I was just not paying attention to the tranny this much before, or since the change it its Now operating correctly.
From what I researched this its normal operation, so no reason to ne concerned. This happens when the torque converter isnt locked up yet. Exactly what I saw on the icarscan.
you can demonstrate this to yourself in a Cayenne ( not sure if the same in the Panamera) by putting the trans in maual mode, accelerate after driving at constant speed, and you Will see the rpms jump up add the TC unlocks.
resetting the tc calibration may have corrected this as much as the flluid change, again, unless I just didn't pay attending before the flush.
long story short, your fine.

 

So Is there an easy calibration or reset for the gearbox , does it learn behaviours like the BMW ZF units

 

Yes it does learn, and I would suppose aged fluid could affect the end result of that learning.

Not sure if there is an easy way to reset the calibration, outside of some OBDII tool. I used my icarscan to reset it, and noticed a difference.
Maybe you can pull a fuse, disconnect the barttery, not sure, others will have to chime in.

There is even suggestions from others to drive a certain way after resetting the calibration, to ensure proper shifting and to avoid some harshness and the dreaded idle dip when coming to a stop (yes, its also related to engine mounts). I attempted it once, but didnt notice any changes, but was told it can take a few attempts. I liken it to bedding in your brakes. You'll have to search for it, on this forum or another one, cant remember.

 

I also run mine from time to time with the PSM switched off, kinda like sport mode (it will drop down to 1st from a stop, hold gears longer, etc.) again at the suggestion of others to adapt the learning of the tranny to be quicker. Again, try a search for this topic.