Hi,

I have a MY04 Cayenne-S. The tiptronic switches was working fine since got the car; today not working after back from dealer by doing a TCU (transmission control unit) adaptation coding. But ending up not working with the TCU I brought in; still using my old TCU. Talked to the dealer they said it has nothing to do. I don't know what to do neither. All other buttons on the steering working except the tiptronic rocker siwtches.

The tiptronic from selector lever is working fine!

Can anyone help please? Thank you!

Paul

 

So they swapped TCU then it didn't work so then swapped bac and now your buttons don't work?


I'd say they missed setting up the programming right to tell the car you have a steering wheel with buttons. Only they (or someone else with the Porsche diagnostic computer) can fix it.

Edit: bare with me here.
There is usually a code to tell the TCU, stereo, HVAC or whatever, what car it is going into and what the options are. For example the same stereo head unit is used in different Cayennes and even other Porsches. So when you install it you have to make sure the "adaptation channel" has the right code in it so the stereo knows what to do. It's usually a ""1234" type of code. If the car has "Bose" the code might change to "1233" or Bose with steering wheel controls and the code changes to "1232" and so on.

The TCU is probably no different. Since the same transmission is used in the Touareg and every version of the Cayenne. It probably needs the right adaptation code inserted to let it know if its being used in a Touareg V8 or a Cayenne V8 with steering wheel controls.

I would bet they looked at the manual and entered the code for "Cayenne S" and not the one for "Cayenne S w/mfsw". (Cause the Cayenne was probably offered somewhere on earth without the buttons on the wheel)


Good luck.

 

Thank you much for your info. Too bad now only dealer having the PIWIS tester but I don't dare going back again; basiccly the dealer mechanic know only changing parts following by its training; but not fixing car. If your issue they never met then they don't know but still charging you money for them to play around; then come out with bounch of excuses and you problem remains still. This is all what I have met and learned from "stealer"! I need to find a good garage that having PIWIS for sure.