nealM

Over the weekend on a long trip, my transmission would jerk and shift from fifth to 2nd gear involuntarily, it happened about 3 times and has not happened since.

I have an appointment with the dealer on Monday, but am worried they will not be able to recreate the issue. My warranty is running out at the end of the month.

Has anyone else experienced this? I'm not sure whether it's an issue with the transmission control module, or maybe a low fluid issue?

Thanks,
-Neal

mistacheese

Yes, I have been having similar issues with my 06 CTTS. I had it flatbedded to the dealer 2 hours away to be told nothing was wrong, (Expected this...) With mine it seems to not want to shift up either. It will hold gears for way too long, I have had this truck for about two months now, and it has only started acting up in the last 2 weeks. Do you do any towing? (I know... "!" ) I do a lot, about 1.5 hours each way to the lake at least twice a week. The boat and trailer are, for the sake of the argument, 5000 pounds. The dealer does think that maybe my issue is that the "adaptive learning" in the transmission is trying to learn shifts for the boat in tow being driven steady, and my wife driving also slow and steady, and me not. (I bought a Porsche for a reason...) But personally this doesn't sound right to me. I am confused as well, but I have had the same issue you have described. Do you also have it sit in 5th at 120KM/HR endlessly until you shift it with the steering wheel switch, and then it holds 6th no worries. (With no boat in tow.) Sorry for the random post, kind of all over the place there.

nealM

Thanks for the response, mine is an 05 CTT with 27k miles.

I don't do any towing, but prior to a recent service, I complained about sometimes longer than normal shifting times / jerkiness. They cleared the adaptation channels and it seemed better.

This problem only showed up about 1k miles after they cleared the channels.

mudman2

For the towing, the adaptive system should have nothing to do with it, you should be in manual when towing, and NEVER above 5

sailorxo

Just curious, why manual only for towing? Can towing be done in automatic with PCM off? Would that help?

ltc

Possible valve body, less likely TCU.
(I'll assume for the time being that the fluid level is correct and doesn't smell like a burnt dinner)
Ask for a new transmission or at least a valve body assembly and verify that the TCU and ECU F/W revisions match.
I love technical gibberish.......where's Gabby Johnson when you need him.

ltc

I'm assuming you meant PSM, not PCM.....

mudman2

Aparently not, all the recomendations I have read from Porsche are that you only run in manual or risk the transmission, the engine or both.

INURGRL951

That is good to know about the towin part so that is a porsche statment mudman2?

mudman2

Yes, check out the manual, I think its in there also

ltc

Sir,
While you're in the manual (sorry, but I can't seem to locate my owner's manual....or my Cayenne), could you please find the section on trailer lighting?
I'm sure it's right next to the section on tow mode and hesitation.
Thank you very much.
Warmest Personal Regards,
Larry

mudman2

who he ?

Slow Guy

The meds are kicking in, the poltergeists have easier access to the keyboard.

ltc

Hey, I didn't use the 'T' word......what do you expect? Besides, towing invalidates the factory warranty, remember?

Go ahead and mention 'BiXenon' and see how long before Toby shows up.

You guys should know by now.

MadFox

Larry.... don't frighten the children.. 'tis a happy place... remember the land of misinformation allows us to own a Cayenne... Dr. W's REAL Porsche vehicle.......