I just had a strange problem with my Porsche Cayenne S, 2004. Has been running like a champ with about 150K miles on odometer. Suddenly today I went to back out of a beach park parking-space and initially it got stuck in REVERSE and would not go to Drive. Even in Park position it wanted to go in reverse. Shut off the engine and retstarted with foot on break. Actuated the console shifter through all gear positions thinking it might be jammed or a sensor problem - no joy. Still was in reverse. Tried it a few more times and finally was able to get it into Drive and get forward motion. Drove it a short distance toward home and decided to try again to see if it was intermittent.

This time as circumstance would have it I parked in a slightly uphill parking space and found that on restart it was stuck in DRIVE still. Turned off and restarted a few times while switching gear selector and it was locked in Drive. I did not notice any obvious mechanical jamming. I did however notice this time that when I went to park position to retsart and cycled the key (old mechanical key in this model) the dash center panel LED would show "P" for a second then immediately go to "D" - rather than the normal 1,2,3,4,5,6, N or P. I googled on my smartphone and found that this might be indicative of "limp mode" and tried resetting by turning key off then on and holding gas pedal down for 5 secs to reset software defaults for shifting logic. But this did nothing.

At this point I turned off the engine and let the car drift down hill in the parking lot to where I could pull out in forward only gear to get back home. Cranked the engine and managed to get home in the "D" position and parked it with parking break since "P" park does not seen to mechanically engage.

I did later notice that the amber "Engine" icon is lit up now too.

At home I removed the center console plastic shrouding to look inside the shifter mechanism to look for obvious problems but found none. Reseated all the electrical connectors and also pulled out the mechanical control-lever/shifter control-assembly and inspected. All look fine. I can physically see the shifter cable coming into the shifter mechanism and it all moves freely. Unless something is broke down below it seems to be physically intact. Put the shifter assembly and console back together and the problem still exists - stuck in DRIVE.

I did notice that the shifter assembly has 2 electrical coils to the front left and front right side with electrical cables connected to them. The one on the right side is pretty WARM/HOT to the touch all the time. I suspected a shorted coil so unplugged the electrical connector and let it cool down then reconnected 10 minutes later (can hear various clicking and actuating sounds in the dash when I re-connect).

Additional History: I have a new battery 1 year ago. About 2 months ago I noticed that sometimes the engine would not crank on first key turn. But on recycle of key it would always start. There's something intermittent - and I was thinking a bad spot on the starter (had the under intake manifold water cooler plastic tube failure 2 years ago and it probably corroded out the starter a bit - my theory). But I am now thinking that with this hot coil on the shifter my battery is really getting a load on it each day due to a shorted coil and its effecting starting capacity. I do notice that sometimes too the shifter drive indicator on the shift console plate weakly flashes "P" when I turn off the engine before I remove the key to exit the car. Again - it sounds related to that hot coil on the shifter assembly.

Going to take it in to the shop as soon as I can since I need the car and can't just leave it in "D" and in a position where I can move only forward to leave.

This link relates to the same problem I had but no one indicated how the person solved his problem:

826548-cayenne-s-gear-shifter-selector-does-not-respond.html


Any help or ideas would be appreciated. But I am suspecting that that hot coil is not a replaceable part and the whole darn assembly is going to have to be replaced...

 

Truth be told you need diagnostics otherwise it's a guess.

 

Need to see what codes are stored in the system.

Cheers

 

It's been a while - but a fairly long time ago - on either this or another Cayenne forum (6-speed or renntech) there was a discussion about this sort of problem on 955/957's - turned out to be some magnets attached to the shifter that came loose. They apparently trigger some hall-effect switches, and once they move out of position the shifter can lock up and give symptoms as above.

A bit of searching on this forum, and the ones mentioned above might be productive - or not.

 

Thanks Deilenberger. I am expecting and hoping its something this simple and not going to be one of those big jobs where there's some obscure solenoid buried deep down in the tyranny that requires a major pull and replace. I was trying to figure out exactly how those magnetic sensors operated and heard that sometimes that dust shroud that glides over the thin flex-plastic electronics film can crack/separate and interfere with gear position feedback etc. When I re-installed it I may have put it in backward since it fits both ways. But the electronics seems to have a magnetic pickup series of cells inside the laminate on the LEFT SIDE.

If anyone has a photo of the proper orientation I'd appreciate it.

Here's a photo I found online showing that dust cover with the magnetic material that is separated into 3 pieces. It shows it on the right side. But it looks to be that the sensor pickup portion of the electronic film is on the left side in my Porsche so I reinstalled it that way.

I can manually force the Triptronic to shift up and down using the stick shift lever in the override mode but feel it shift gears +/- when in forward motion but the dash LED only shows an inverted "D" rather than the 1,2,3,4,5,6 gear like it normally does.

 

It turned out that the shift cable was broken. Apparently the connector just separated from the cable and it needs a new one.

Sticker shock on the labor and parts costs. Would have thought a simple cable pull using the old cable to route the new one would be less than a 30 minute job. But that of course would be too simple - apparently a lot of intermediary strain reliefs etc. in the path requires pulling out the whole console, seats etc.

Weird that it would just break after all this time with no heavy strain on the cable. It never was hard to actuate the shifting lever inside the cockpit. One of those things...

Thanks for the help...

 

Thanks for following up on this! It is so rare that people do. What was the total damage for parts and labor?

 

Glad I did not attempt to do it myself. Apparently the procedure requires tilt dropping the transmission down to fish in and adjust the cable length by trial and error. Took them 5 retry times I am told to get it finally adjusted. Over 7 hrs of labor - the mechanic earned his pay on this one. About $1,500 - $200 of that is parts. The convenience of getting the loaner Porsche made it a no brainer to have the dealer do it as they are one of the top rated in the nation in service and sales.

 

Additional follow up info:
The reason the Check Engine Light illuminates is because the self-checks sense a discrepancy between actual gear of the transmission and the shiftier console selector. Not surprising due to the cable being physically disconnected and left in Drive level position down below.