Shifter / tiptronic acting out

[tcooper]

Hello All,

My 04 S has recently started doing some wired stuff between the shifter, dash display, the tip tronic controls on the steering wheel and shifter +/-.

The strangeness started 6 months or so ago when it would occasionally go into Manual mode. A quick flip of the shifter into M and back into D fixed it.

Most recently, it has decided that it prefers M over D. Flipping the shifter back and forth rarely fixes it now.

Other things to note: (observations)

most of the time, the LED indicator on the shifter only shows it in +/- regardless of position. The dash shows the correct position except for D.

some of the time, the LED indicator shows nothing. The dash is correct except for D.

most of the time, using the shifter +/- to change gears does not work. Have to use steering wheel controls.

some of the time the steering wheel controls will not downshift. (REAL annoying!!) they always upshift.

The problem seems to be worst in the mornings when cold and better once everything get warmed up.

Looking thru the forum, I'm torn between the transmission control unit or the micro switches/magnets around the shifter.

Any thoughts??

Thanks,

Trey Cooper

[Loren]

Whenever I see strange electrical faults on a Cayenne - I suspect battery and grounds.

[tcooper]

Broke out the durametric cable today. I found a code 1045 in the TCU. The description said it couldn't figure out the shifter position. I cleared the codes and it seemed to do fine but a few minutes later it started back in 'M' all the time.

On the grounds, is there a diagram of the ground points in the cabin? What's the best way to take apart the center console without breaking everything?

I did replace the battery back this winter. Terminals were in great condition.

Thanks,

Trey

Edited July 13, 2013 by tcooper

[wvicary]

Inspect the magnets for the hall effect switches located under the upper shifter housing. I seen loose change dislodge the magnets or sometimes they just break free and need to be glued back into place.