I have a 955 turbo cayenne and have started getting the error message for my transfer case stepper motor failing and I also noticed that the switch for transfer case does not light up. I read the TSB and noted the recommendation about replacing the transfer case motor and transfer case control !module to updated ones. Am I safe to assume that the cayenne and toureq transfer case modules for similar years are interchangeable. The TSB has the updated control module from VW as 0ad927755BT and Porsche number 95561802503 but looking in parts catalog, there are newer modules ending in BD and BG and the BT module does not even come up in the VW parts catalog anymore.