While running in my first DE event this weekend in my fairly new to me 2009 997.2 C2S Cabriolet with about 11K miles, the PDK transmission suffered a problem during which it would go into 7th gear and stay there for a while. I would notice this only when trying to accelerate from the apex of a corner. The car would not accelerate and I noticed it was in 7th gear but would not downshift. I was running it in automatic mode not using the shift buttons. This would occur in either sport or sport plus setting and it only happened on a curve. I got no warning lights or messages. After being on the straights for a while, the transmission returned to normal operation.

The only thing I can imagine is that transmission fluid is low with the curve causing it to slosh to one side leaving the other side dry and activating some sensor resulting in the transmission to go into a limp mode. "Search" came up with no similar threads.

If anyone has experienced this, what was the diagnosis and cure? My car is in CPO warranty so will soon take it in to be checked. Left the DE early so as not to cause damage.

 

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I can't imagine the transmission would shift to 7th in sport plus on track. If I drive on the highway in sport my car rarely shifts to 7th. Do you know your speed when the car shifted to 7th?

I have no idea why the transmission would stick in 7th unless you inadvertently put it in manual. I did that once.

 

It was not in manual when it shifted to 7th. I checked that. There is no place on the track where it would normally shift to 7th.

 

I too have not noticed the car going into 7th in spirited sports mode driving.

 

Odd, Sport + is specifically programmed to lock out 7th gear altogether.

 

Hpoefully there will be some codes that will help with your diagnosis. Maybe change the fluid if nothing else is found.

 

If your in Sport or Sports plus it won't go into 7th gear. This happens to my car. If your in 7th in standard mode, then press Sport mode it'll drop to 6th.

 

Well, it did. Maybe a failsafe mode.

 

Maybe the fluid got too hot and the software is programmed for that?

 

^^^ Agree ! So the fact it actually went into 7th in Sport+ is a problem. The PDK is supposed to be a sealed unit with minimal maintenance required. I'd have a dealer check it out. A couple thoughts if it ever happens again: 1) exit the roadway/track safely ASAP and turn off the car and remove the key, exit the car and lock the doors with key fob. Unlock and start it up again. Press Sports+ and slide the shifter to manual. Drive along in 1st up to redline, do not shift into 2nd, let the PDK bump the rev limiter, ensuring it will not shift (if it is working properly it will only bump and not shift). Release Sport+, use normal mode and repeat (remain in manual), this time you should get a moderate to hard shift into 2nd. Should not be any CEL's or transmission protection codes thrown in these cases. 2) this option would not be my first choice but may also help in diagnostics. While continuing to drive, slide the stick into manual mode and attempt a forced downshift. May need to ease off the throttle and reduce engine rpm such that the requested shift will not exceed redline of the lower gear (e.g. 6th - if it will not downshift then go to option 1 above). Turn off Sport+ and accelerate and attempt a shift into 7th. Press Sport+ button, you should get an automatic downshift into 6th (even in manual mode). If not then something is goofy with the electronics (the previous shift tests help to isolate the mechanical versus electronics) - take to the dealer, unfortunately the PDK is probably best serviced by the dealer for now.

My guess from your description is you have an electronics issue, not a mechanical one since you were able to drive it home. I've seen and have had some wierd electronic things happen to PDK in 997.2 cars, sometimes the turn off, key out, lock and unlock, resets it and then it works fine. But as noted above, probably worth a stop at the dealer service department.

 

Info from the 2009 Service Information Technik Introduction All 911 Carrera Models that may be useful to your diagnostics.

- "Driving in selector-lever position “D”, Sport active
An extremely intelligent driving program is also activated in this position and shifting adapts continuously and almost seamlessly to the driving style and route profile over the entire operating range. Basic sportiness is increased with faster pick-up and slower deceleration. Gearshifts are more performance-oriented and the engine torque is only reduced slightly during upshifts and downshifts.
Downshifts in deceleration state and deceleration downshifts are accomplished with intermediate throttle application and are therefore audible. The vehicle moves off in 1st gear. 7th gear is avoided for the most part and is engaged only at higher speeds."

- "Driving in selector-lever position “D”, Sport Plus active
Shift map adaptations are not active in this program. The most sporty map is activated permanently. Gearshifts are performance-oriented with reduced gearshift comfort. Downshifts in deceleration state and deceleration downshifts are accomplished with intermediate throttle application and are thus very audible. Gearshifts are performance-oriented
and the engine torque is not reduced during upshifts and downshifts. The vehicle moves off in 1st gear. 7th gear is not available. The racing start function is available."

- "Gear retention while cornering
The lateral-acceleration sensor (single component with rotation-rate sensor), which is located under the centre console and works for the PSM system, is used to detect lateral acceleration and retain the engaged gear and lateral acceleration in the relevant gear, depending on the shift map."

- "Overheating protection is activated in several stages and actively prompts the driver to adapt his driving style. Clearly perceptible jerking occurs in the first stage due to
continuous opening and closing at drive-off and crawling speed, thereby prompting the driver to change the driving situation. Engine torque and kickdown rpm are also
reduced. This is not displayed in the instrument cluster. A fault is stored in the control unit."

 

Maybe a failsafe mode, but time to go back to the dealer and get it checked out.

 

Search the Cayman board for PDK on the track. They are one or two race teams that use the PDK in the Cayman Interseries. Find one of the posts for contact information and contact them to see if they have ever experienced your problem.

 

Do you have paddles or buttons? A couple of things I found out with my PDK car. As others have stated in sport settings/auto the car will not go into 7th ...however if you manually upshift it from 6th even though it is in auto it will go into 7th for a very short period. Try it on the highway. What I found on the track when I first got the car was that in hard cornering it was easy for the palm of my hand to inadvertently hit the upshift button. Took me a while to figure out why I was in a higher gear coming out of the corner. It would hold that gear for about 10 seconds or so and then back to normal. Convinced me to get the paddle shift wheel. Hopefully your problem is this simple.