I'm trying to pin down a Tiptronic issue...
 

... for a friend of mine.
He has a 2004 S SE-550 with less than 4000 miles (no typo) on the odometer, but now out of warranty due to time.
The issue is that the tranny will sometimes indicate that it has shifted from D to N although it is still in D.
Sometimes it actually shifts itself into N.
This generally happens when you shift from park to Drive, bu can also happen sometimes when going over rough terrain such as RR tracks.
The car shows no errors in the Tiptronic or ECU or Cluster or anywhere else.
The Dealer has already replaced the Multifunction Switch, has adjusted the cables and recently replaced, under Porsche good-will the tranny's Controller.
But the problem still persists.
He brought it over to the shop while the car was having the issue and I was able to connect the PST II to it and actually see that the Multifunction Switch opens and closes by itself with the car idling, in Drive.
I'm just trying to find out if anyone else with a Tiptronic has gone through similar problems and what the final solution was so that my friend can finally start enjoying his "old" new car.
I don't have a lot of experience with Tips.
Happy Boxstering,
Pedro

I had a similar issue with the multi-switch when I first got my car.

Instead of shifting to N, or not shifting, but indicating N such as yours, under similar conditions that you describe, my car would not enagage the M mode when the shifter was set to M. Instead, I got the dreaded 4th gear indicator flashing on the dash, even though the tranny worked perfectly automatically, even though it was set to M.

It turned out that the multi-switch was dirty from road gunk. Ever since cleaned and adjusted, it has worked properly w/o incident.

My guess is that the one you describe is improperly adjusted. There's a fine line in getting it dialed-in or not.

Cheers!