"M"/tiptronic transmission not working?

[knicksplayer]

Hi guys, I have a small issue. I never really use the tiptronic mode on my 02 porsche boxster but for the sake of it I decided to put the gear into M and test it. To my surprise, when I shifted to M, it made no difference and the dashboard was still showing D. Couldn't change gears or anything, it really was in Drive. I have no issue shifting into P, R, N & D. Does anyone know what the problem is? Is it a common one? What would need changing? Transmission? I mean, it's not like I use that option often but again I was surprised to see it wasn't working, I remember testing it out a few months back and it was fine.
Thanks for your help!

[tonycarreon]

according to the manual, if there is a fault in the transmission, the 4th-gear display flashes and the transmission no longer shifts.

additionally, if manual mode fails the electronics switch to automatic mode and the display will stay in "D".

either way, it's not normal. have it checked out.

[jcb986]

My 2000 sometimes reads drive when I place it in manual mode while driving, but once I start using my thumb shift it then will register manual mode. Try it sometime and also try putting it in manual mode before start down the road.