GeneSequence0

Hi there!

I have recently purchased a 2014 991.1 4S automatic and after a few miles, I encountered a problem. When I fully kick down the gas pedal (until maximum and also right before the kick-down), the PDK does not shift past the 3rd gear. It keeps revving around 5000 revs. I have to lift my foot from the gas pedal and eventually the revs lower and the PDK shifts again. This happens in normal mode, I have not tested it in sport or sport plus yet. When I drive more behaved, that is without pushing down the gas pedal too much, the car behaves normally.

I have also tested manual shifting during kick-down in manual mode. Shifting from 3rd to 4th gear here also does not work properly, it seems to be stuttering and eventually shifts after lifting my foot. In manual this also happens at lower revs and only with max / almost max throttle.

The problem did not appear during the test drive pre-purchase. Although I did not test this extensively.

Does anyone have an idea about what this could be? Is there a possibility for an easy fix or could this mean PDK replacement? The car will go back to the dealer soon as it is (luckily) under warranty. Any input beforehand about what the problem could be would be appreciated.

Thank you in advance.

cbredesen

This sounds contradictory...

I'm not sure this is weird or a problem but maybe I misunderstand. If you are applying nearly full throttle I would expect it not to shift until late, even in normal mode. Will it shift if you pull the right paddle?

GeneSequence0

The car does not shift past 3rd gear and keeps revving in 3rd gear at around 5000rpm. This happens when I fully push down the gas pedal, but also when I push down the gas pedal until right before the kick-down. Maybe also at less throttle than right before the kick-down, but I have not tested that yet. Hope this is more clear.

cbredesen

This does sound weird. It behaves normally when driving more gingerly?

GeneSequence0

Yes, then shifting behaves normally.

Porsche_nuts

If you think that is weird, try doing it in sport plus. You won't shift out of 1st gear until near redline.

raaizin

It will not shift from 3-4 unless you hit redline. 5000 rpm is nowhere near redline. it will hold third gear for a while. it is not like a traditional auto which will upshift as soon as you ease off the gas.

Jack F

Is this happening in Sport or Sport Plus or normal driving mode?

doctj

Upload a video of this to YouTube and link it here so we can see.
is it modified with an ECU tune or a TCU file as far as you know ?

vanlieremead

Exactly. If you are pushing the car, the PDK thinks you are in a mode demanding max power to the wheel. Even when lifting the revs stay up expecting more. Eventually when lifted the car settles down.

GeneSequence0

Hi All, thank you for your input so far.

Maybe I did not explain it properly. The car did not accelerate further and stayed at 5000rpm. I was still pushing down the pedal. The car was revving at 5000rpm and did not accelerate. Like there was a limit it was hitting. This happened 4 times in a row. The car did only accelerate further and shift once I released the gas pedal and pushed the throttle more gently.

Today, I was at the mechanic (Porsche specialist where I bought the car) but we could not reproduce the issue. Which is very weird. There are no error codes to be found according to the mechanic and they don't know what the issue could be.

I am a bit worried that this is an issue with a slowly dying PDK or something else, and there will be a dramatic and expensive failure after the warranty.

GeneSequence0

I will try to make a video once I am able to reproduce the issue. There had been no tuning of the car as far as I know.

GeneSequence0

All, thank you for your input so far.

Maybe I did not explain it properly. The car did not accelerate further and was revving at 5000rpm. I was still pushing max or almost max throttle. It was like the car was hitting a limiter. The car should have either accelerated further and increased rpm until redline, or shift and accelerate. This happened 4 times in a row, in automatic and also in manual mode while shifting using the shifting pedals.

Very weird indeed. Today I was at the mechanic and we could not reproduce the issue. There are also no error codes to be found.

I am a bit worried that this issue is due to a slowly dying PDK or something else, and will result in a catastrophic failure later on after the warranty.

CSK 911 C4S

I'd have the PDK reset via a dealer computer.

I hope this is a CPO car?

dannyk304

If what you're saying is that the car, under full Open Throttle acceleration only goes to 5k RPM and hangs there without shifting or going beyond 5k, yes, sounds like an issue. But in may not be the PDK at all, more ECU related. Could also be PSM related. Curiously, you have no codes or fault warnings? Do you notice the yellow PSM light come up on the dash when this happens? If the PDK were having a mechanical issue to not allow it beyond 5k I'm sure there'd be some warning. If the PSM is acting up, perhaps it believes everything is normal and so no warning. My take based on the limited info. Good luck.