997 Trans Issues? Faulty Park Switch May Be the Culprit

Hey there! I went through something similar with my 2014 Porsche Cayman (I have some experience working on cars). The symptoms you're describing sound exactly like what I dealt with, weird shifting patterns and warning lights. It turned out my transmission control unit (TCU) was failing. I took it to my trusted Porsche specialist, and they diagnosed it as a faulty TCU. The whole thing, including parts and labor, set me back about 1000€. They had to replace and reprogram the unit, but it's been shifting like a dream ever since. Could you share more details about your specific issue? Like: Any error codes? Does it happen more when the engine's cold or warm? Are you getting any specific warning messages? This might help narrow down if it's the same problem I had.

Thanks for sharing your experience! My car has 91447 KM and was just serviced last month. The weird shifting mostly happens when the engine's warm, usually after about 15-20 minutes of driving. Haven't pulled any error codes yet, but the warning light's been pretty consistent. The transmission seems especially jerky when downshifting from 3rd to 2nd. Your TCU issue definitely sounds similar to what I'm experiencing. Might have to bite the bullet and get it checked out by a specialist. Was hoping it'd be just the parking switch since that's a cheaper fix, but better safe than sorry with these things!

Hey again! Thanks for those extra details about your 997. You know, after dealing with my Cayman's transmission issues, I can totally relate to hoping it's just the parking switch! But hearing that it acts up mostly when warm and specifically during 3rd to 2nd downshifts, I'm even more convinced it's similar to what I experienced with my TCU problem. I remember my Cayman did exactly the same thing, drove fine when cold but got really jerky once warmed up, especially on those downshifts. One thing I didn't mention before, before I got it fixed, I tried resetting the transmission adaptations (basically unplugging the battery for 30 mins), but that only helped for like a day or two. If you haven't tried that yet, it might be worth a shot, but honestly, it's probably just buying time. Since your car's got similar mileage to what mine had when the TCU went (I was around 85,000 KM), I really think you're dealing with the same issue. These Porsche TCUs seem to have a bit of a lifespan to them. I know it's not the answer you were hoping for cost-wise, but trust me, once it's sorted, it's like driving a new car again. Let me know what you end up doing, I'm curious to hear if it turns out to be the same problem!

Thanks so much for all the detailed info! That's really helpful to know about the TCU issue being so similar, especially with the warm engine symptoms matching up. I actually haven't tried the battery reset trick yet, might give that a shot while I'm setting up an appointment with my specialist. You're probably right about it being the TCU rather than just the parking switch. Better to face the music now than risk bigger transmission problems down the road. I'll definitely update this thread once I get it diagnosed and fixed. Really appreciate you taking the time to share your experience, it's super helpful having someone who's been through the same thing! Thanks again for all the advice!