I have a 2017 Macan GTS with 36,000 miles, regularly serviced at local Porsche dealer and have had no issues with anything until last week. While driving to work last Wednesday, two warning messages appeared. First said "Transm. Fault, Poss no R gear, Drive on possible". Second message said "Engine control fault, Consult dealer, Driving permitted". Macan started shifting erratically and would only shift in 2nd, 4th and 6th gears. I drove to work at 50 mph and called dealer and they told me to drop it off on way home.
I dropped the Macan off after work and the dealer put me in a brand new 2019 Macan base loaner. The next day the dealer informed me that one of the solenoids on the transmission valve body (also called mechatronic unit) was stuck in the 5th gear position and it caused the erratic transmission behavior and the warning messages. The dealer was waiting for the mechanics diagnostic report and warranty approval. Porsche authorized a new PDK transmission valve body which has electrical and hydraulic components built into it. (photo attached, weighs 35 lbs. per my mechanic) My advisor told me the part alone is $900 plus 3-4 hours of labor.
The dealer called me Friday at noon and said that my Macan was ready! The dealer had these parts in stock, which may indicate this is more of a common issue. Repair also included new PDK fluid which normally gets replaced at 40,000 mile service.
Luckily I was under warranty and did not cost me anything. So far the Macan is riding fine. My mechanic said it will feel like a new transmission and the car will need to learn my driving habits all over again. Shifting is super smooth. Hope this is the end of this issue, scared the heck out of me.
BTW, I was very impressed with the Macan base loaner with 18" wheels. The new PCM screen is nice but noticed the font and touchscreen icons were small and wasn't so user-friendly. Not sure if these can be adjusted...
Transmission Valve Body Photo