GM Austin

I have not had a kickdown update done. The dealer made reference to a transmission update when I first inquired about the lurching issue. When the dealer checked he found that mine was built after the update was incorporated into regular production units. I believe the transmission update is a documented TSB (NHTSA #284737) and requires replacement of the transmission thermostat.

Is this the update you are referring to?

mudman2

I tried some straight line testing but was unable to. Can you give me a specfic test scenario as I don't think that I have this issue.

If I tip down or blip the throttle I am off to the races, equally if I press down gently it takes off.

On cornering I most definitely see it.

Mike

GM Austin

We have been talking about the DME remap as if there is a single solution. I guess we need to leave open the possibility that there could be a variety of DME mappings being installed.

I just did some testing and I still have a hesitation when going straight. I was going about 60 mph in 6th gear at a steady throttle. I backed off the throttle completely and coasted for about 5 seconds. I then gave it about 3/4 throttle and observed the shift indicator move down to 3rd and then a fraction of a second later I got strong acceleration. I also tried the same thing around a curve and had the same result. MAYBE more hesitation on the curve, hard to tell for sure.

Another thing I have noticed is that this is not just a transmission downshifting issue. At least not for me. I also notice the hesitation at low speed while the transmission is still in 2nd, the gear it starts in.

I saw on another forum a dealer had told the owner that three maps were available: Asian, US and ROW. Some Cayennes had shipped with the Asian map by mistake and this was the basis of the hesitation issue.

mudman2

oh

more research I think

oh

GM Austin

Exactly!

GM Austin

I have now lived with the DME remapping for a couple of weeks and I think there are still unresolved issues. To be specific, with the car is in automatic mode with PSM on, you slow to 15-20 mph to go around a corner and then accelerate when coming out of the corner, you will sometimes experience a second or two of "dead pedal" where no acceleration occurs, and then you get strong acceleration.

I took my car back to the dealer for an oil change and cornering light fault and told them to check on the hesitation problem again. I told them I still had hesitation problems, especially when cornering. The car was returned with the report that it was functioning normally.

I have spoken to other owners who also experience hesitation problems, even after the remapping of the DME, so I don't believe Porsche has a complete solution yet. I am also coming around to the belief that the gear selection indicator may not be entirely accurate. It sometimes indicates a downshift has occurred before the transmission really downshifts. I had watched the indicator in the past and saw that hesitation continued even after the transmission apparently downshifted. I now believe it had not actually downshifted yet and for this reason I believe the hesitation is mostly a transmission downshifting issue.

I would like to hear comments from others who have had the DME remapping done to see if their experience is similar to mine. I also don't want to make a bigger issue out of this than is really there. I have driven many cars that behave exactly like this so I am not sure we can label this a defect.

However, I also own a BMW X-5 and it does not have this characteristic. It has very smooth downshifts at all times and always seems to be in the right gear at the right time. Acceleration when coming out of a corner is always immediate and is completely controllable with the throttle. It is this comparison with the competition that makes me aware that Porsche can, and should, do better.

Torags

GMAustin; does your X5 have throttle by wire? Who is the manufacturer of the transmission?

SFernando

I, too, had the DME remap done a few weeks ago and while things feel slightly smoother the hesitations that GMAustin talks about are still very much present. I also can relate because my previous ride was an X5 which was downright silky in the power delivery department in virtually all driving situations--albeit with less power to deliver!

I had an informative and helpful discussion with the service manager on the issue: long story short, including numerous illustrative diagrams, etc., was that this won't go away because it is reflective of the inherent compromises between the vehicle's significant acceleration, PSM inertia sensors, driving style memory, overall electronic complexity, etc.

What he said seems plausible to me, and differentiated between the "tip-in" hesitation for straight-line acceleration and hesitation when taking a turn, especially a tight one. The first can be dealt with, the second not, according to him.

I know: all this does is make the issue clear as mud, but our collective experiences suggest this is something without a simplistic fix.

SFernando

Torags,

I brought up the X5 and the service manager said it has throttle by wire. Don't know about the tranny.

Torags

The manufacturer of the Aisin tranny in the Pepper, might have torque conversion requirements that PAG must follow (my guess), that may prevent change by local techs.

OEM insulate themselves from liability if their recommendations aren't followed (re: Firestone & Ford mtire pressure)

GM Austin

That's a theory worth considering. I don't know who makes the transmission on the BMW. I am not really into the X-5 like I am the Porsche. In fact, the main reason we have the BMW is because Porsche took so long to develop the Cayenne. At the time, we needed to unload a Ford Explorer and the X-5 was the best available choice. I have been very pleased with the X-5's performance and the dealer service. It helps me tolerate the scores of electronic gremlins it has; at least three times the problems the Cayenne has had. I believe it does have drive by wire. How about ZF as a guess on the transmission?

rockitman

I had the transmission update/recall...replaced thermostat and some seals. It was never leaking...The dealer went out of their way to notify me of the recall. Amazing. They also remapped the ECU and the lag/lurch is gone. Immediate power!!! I am very pleased with the cars performance now...:-)

okindao

What a thread.......

It helps confirms my decision to purchase for my wife a 2003 Infiniti QX4 loaded for $ 32,000 ( $ 38,000 sticker) with a zero % interest rate over 3 years....I have been back once to the dealer for the 5000 mile oil change ($ 60.) no other issues or problems at all

If I has spent the 60 k plus you all have ( non turbos) I would be insane over dealer visits ,recalls, lurching and other issues reported on this board for a new vehichle.

I am a Porsche lover but after reading this board would not consider the Cayenne....... It seems that Porsche still has many unanswered questions as to this machine and that dealers are not together and consistently knowledgeable.

Hope you all get these issues resolved in the near term and can fully enjoy your purchases

jhunt@huntinter

Just to toss in, my '03 Range Rover does not have this hesitation issue (throttle by wire, powered by BMW eight cylinder and I think a ZF tranny). Whereas my wifes A6 turbo with tiptronic most certanly does have the problem. I think this is a VW/Audi/PAG issue with Tiptronic. Something they really need to fix, especially since the competition doesn't have an issue with is.

Would be curious to know if the A6 tranny is Aisin?

John
'79 930

mudman2

This thread is physically to long, I am closing it now, if you wish to continue please start a new one.