My 03 996 turbo tiptronic transmission goes into safe mode (locks into 2nd gear) every time I auto cross it. Can then have shop reset "invalid wheel speed sensor signals" and transmission is fine. No other faults. Can not get it to lock up on the street even with very aggressive driving. How ever, next month, auto x same exact thing. Tried disconnecting battery and joining + and - cable in an attempt to re-set but no dice. Again shop reset "invalid wheel speed sensor readings" and Trans is once more fine on the street. Has anyone else experienced this? I did search forum and read "tiptronic emergency run mode" but in all those cases transmission was hunting or slipping which is not my problem. Would like to know if anyone else has experienced this.

 

I would assume you turning your traction control off? These cars are very sensitive to wheel spin, especially one end turning faster or slower than the other. I believe that kind of activity is what causes premature failure of the differentials. Maybe someone else with a Tippy can chime in.

 

First auto x stability management on, second one it was off. Same problem both times. Both times shop cleared code P0175 N2, N3, Inplausible wheel speed and then transmission unlocked itself and runs perfectly on street.

 

I may be off here but, but looking up P0175 seems to have other people looking into System too rich, bank 2.

I find this reference in Rennlist as well as other places?

http://upkeep.us/OBDII/OBD2/Porsche/piart.php?art=202