Cayenne Transmission Downshift Issue

[motorsailor]

My 2006 Cayenne Turbo S has done a couple of odd things. On several occasions while making a turn at slow speed and then accelerating aggressive after the turn the transmission drops into first gear and will shift out unless I let off the accelerator. It seems to get hung up it first. It has now done this three times in the last several weeks. Has anyone experienced this or have any idea what is going on?

Thanks

John

[RFM]

Looks normal to me, at slow speed, hot engine, and under the circumstances you describe, the transmission use the second gear, with W.O.T. the Tiptronic will switch back to first gear and stay there till the max. RPM is reached or the accelerator is released. You can (let) read out the fault memories with a diagnostic tool for peace of mind.

[wvicary]

I agree with RFM, it sounds completely normal depending on how much throttle you're applying exiting the corner. Is the vehicle new to you or this problem has recently started.

[motorsailor]

I agree with RFM, it sounds completely normal depending on how much throttle you're applying exiting the corner. Is the vehicle new to you or this problem has recently started.

I bought the Cayenne a view months back. The reason that it does not seem completely normal is that it only happens making a turn. I have tried to get the same response on a straight path and it accelerates and shifts at a reasonable RPM. The situation I am talking about is after a slow to normal speed turn, upon aggressive acceleration it drops into first and the engine just revs and does not shift out of first. It seems to lock itself into first. I do not have much experience with the Cayenne, that is why I was seeking input.

Thanks for the response. Additional comments appreciated.

John

[odix]

Some ideas:

Low speed/sharp turns place far more load/friction on the drivetrain then accelerating in a straight/no turn. Keep in mind Cayenne's are heavy and have wide sticky tires. Due to the increased load while turning a kick-down to 1st gear makes sense -- especially if you are accelerating aggressively. The exact same acceleration-level on a straight road may not trigger the same drivetrain load and therefore a forced kick-down to 1st may not occur. Once in 1st Cayenne's like to go to high RPMs before they shift to second. You can always use the steering wheel shifters (or gear selector) to shift into second, etc. I do this sometimes. It's a bit uncanny when I want to merge onto a freeway, step on it, and suddenly I'm in the high RPMs for each shift point.

The vehicle "learns" driving habits and mirrors what it thinks you want. Be sure you're not at the tail-end of a driving style/habit cycle when this issue occurs -- if you're aggressive in a few instances and then back off and drive more sedately you may be skewing your experiment on the turn vs. no turn acceleration test -- and vice versa, drive mellow for awhile and overall accelerations/shift points mellow out, drive aggressively and it's high RPM shifting again.

Also try turning off stability management (button in center of dashboard) and repeat the exercise. Starts in 2nd gear will be disabled (1st will be where you always start with PSM disabled) but you can note the RPM/shift points on turns vs. straight/no turn acceleration.

Update: See shiftmap note in review of a 2008 Caynne S.

Edited April 18, 2010 by odix

[wvicary]

It shouldn't be selecting 1st gear unless you have foot in the throttle 100% but hard acceleration should downshift into 2nd gear-depending on the speed/RPM carried through the corner. If it indeed does engage 1st gear it should shift into second at redline.

[ManMN]

I’m a new ’04 Cayenne S owner; I believe I have the exact problem. When the engine is cold, it is more severe; it happened to me a couple of times when I sit at an intersection waiting for the traffic light to turn green, when it turned green, I stepped on the accelerator, the car moved enough so that it’s right in the middle of the road then the car paused [stopped]. I think at that time it’s searching for the right gear then suddenly it switched to first gear and jerk real hard then it moved on.

So now when I first drive the car, I use manual mode until the car really warmed up…

I’m still looking for an answer. If anyone has any suggessions, please advice.

Thank you in advance.

ManMN

[wvicary]

You have a different issue and need to have the fluid level checked and fault codes read out.

[boyer2003]

I'm a new '04 Cayenne S owner; I believe I have the exact problem. When the engine is cold, it is more severe; it happened to me a couple of times when I sit at an intersection waiting for the traffic light to turn green, when it turned green, I stepped on the accelerator, the car moved enough so that it's right in the middle of the road then the car paused [stopped]. I think at that time it's searching for the right gear then suddenly it switched to first gear and jerk real hard then it moved on.

So now when I first drive the car, I use manual mode until the car really warmed up…

I'm still looking for an answer. If anyone has any suggessions, please advice.

Thank you in advance.

ManMN

I have a similar issue with my 04. It does not seem as severe as yours, but when it is cold it always goes in to D1 and shifts hard if you don't shift manually. Recently i have noticed a very slight grind fromD1 to D2, only when cold. I am trying to research a local shop that can do a fluid change and perhaps a trans service - afraid the dealer will screw me! I also have a differential whine when cold. I'm guessing its ready for fluid changes?

[odix]

Hi -- two different issues at play here. ManMN has a potential problem and needs it looked at by a mechanic -- boyer2003, what your issue sounds like is standard Cayenne operation: when vehicle/emissions/exhaust/catalytics are cold you'll always start in first and the shift to second may be abrupt. Note that it's the vehicle temp which controls this -- not ambient temp. It will happen in both summer and winter when your Cayenne is cold and just started.

I don't think you have any problem at all. Do this -- on your next drive that's over 20 or 30 minutes and the fluids are warm, turn off the ignition, pull the key out, then a few seconds later restart and get underway. You should start off in second. (Make sure PSM is remains on.) If you start in second all should be well.

[mudman2]

wow a veritable cornucopia of descriptions of 03/04 issues and tranny control unit problems. 03/04 people get used to it unless you can shell out for an 05 tranny and control unit

turbo, get piwis on the system and make sure tranny control unit is ok

[ManMN]

Thanks for the comments. I'm shopping for a reliable independent mechanic that won't eat me alive. For now, when it's cold, I'll just shift it manually.

ManMN

[Clutch-n-Throttle]

Sometimes when I turn the steering wheel, I'll inadvertently hit the Triptronic swith on the steering wheel. This causes the tranny to shift to a lower gear. If its at slow speed, it will shift to the first gear. Just an additional tidbit

[dpolson]

SO is it normal for an '04 Cayenne Turbo to ALWAYS start out in 2nd gear from a stop? Or is this a programming issue? My PST2 does not show any transmission-related faults. Or does the transmission control module need to be replaced?

[deilenberger]

SO is it normal for an '04 Cayenne Turbo to ALWAYS start out in 2nd gear from a stop? Or is this a programming issue? My PST2 does not show any transmission-related faults. Or does the transmission control module need to be replaced?

Always? No.

It will start out in 1st if it's cool enough out and the engine has just been started. This is done to help heat up the engine and O2 sensors quickly. Other then that - it always starts out in 2nd from a stop, and that's not programmable.

[dpolson]

Many thanks, Don. Here's another issue you might be able to advise me on. The transfer case will shift into low range and lock and unlock the center diff, but will not then shift back to high range. THe stepper motor is fine (I swapped with my Touareg to make sure). Is this a control module issue? Transmission control module? Or is there a transfer case control module (the other box under the driver seat witht he tranny module??) Or something else? PST2 is not helping me with this one.

[deilenberger]

Dunno. Aside from making sure mine switched to low range and back, I've never delved into the working bits.. so dunno. Perhaps one of the techs hanging out here can track down where the control module is. If I had to guess - the system is designed to prevent doing the switch while moving, so perhaps some signal isn't getting to the module to tell it you're not moving when it's in low range.

Are you permanantly stuck in low range now? Hate to think of what the fuel mileage would be..

Oh - a thought - a Durametric should be able to check that module and tell you what info the sensors feeding it think they're sending back to the module.

Edited May 10, 2012 by deilenberger

[ckeyes888]

Same issue on a 2008 Cayenne S. When accelerating fairly hard out of a turn the transmission will revert to manual mode, reads M1 on the dash readout, and will not shift out of first gear. Ridiculous to think that could be in any way normal. It’s actually quite annoying.

 

Carl

Edited April 19, 2018 by ckeyes888

[Abdullah]

Good day. I recently purchased a 2012 Porsche cayenne gen 2 Diesel,  Whilst driving normally it changes gears fine , reaching 8th gear, If I accelerate harder it does not down shift at times, it stays in 8th gear. Sometimes it down changes. On a fast take off it will change at 2500rpm and changes the gears quick and reaches 8th gear quick.  What could the cause be? Thank you guys