991 C2S Cab window issue

[2geeze]

Just curious if this has been an issue for anyone else--my 2015 C2S cabriolet (about 48000 miles) has developed an issue within the last year in which the passenger window unpredictably lowers a little bit from its fully raised position while driving, causing it to vibrate annoyingly. You then have to roll the window fully back up and it seats back in position. This happens unpredictably while driving but will usually happen at least once if the car is driven for 30 minutes or so; it may happen more than once in the course of a drive. I had it serviced 6 months ago by the dealer, who replaced the window motor. This seemed to largely fix the problem for a while but within the last few weeks it has started doing it again. It seems unlikely to me that a second motor would promptly fail and cause the same problem. Is there maybe a sensor for window position, or some issue with how the window physically stays in position? Anybody have any thoughts?

Thanks in advance,
Brad

[Tom]

Just curious if this has been an issue for anyone else--my 2015 C2S cabriolet (about 48000 miles) has developed an issue within the last year in which the passenger window unpredictably lowers a little bit from its fully raised position while driving, causing it to vibrate annoyingly. You then have to roll the window fully back up and it seats back in position. This happens unpredictably while driving but will usually happen at least once if the car is driven for 30 minutes or so; it may happen more than once in the course of a drive. I had it serviced 6 months ago by the dealer, who replaced the window motor. This seemed to largely fix the problem for a while but within the last few weeks it has started doing it again. It seems unlikely to me that a second motor would promptly fail and cause the same problem. Is there maybe a sensor for window position, or some issue with how the window physically stays in position? Anybody have any thoughts?

Thanks in advance,
Brad

I had an '18 991TTS and it did something similar. I can't remember the exact circumstances, but the window would un-cinch -- i.e., when you close the door with the window up, the window moves up a little bit after the door is closed to seal it all up -- at times, it would undo that on it's own. If memory serves, the passenger side mirror would move on it's own too. The dealer ended up doing a software update and that fixed it...

[2geeze]

[/quote]


I had an '18 991TTS and it did something similar. I can't remember the exact circumstances, but the window would un-cinch -- i.e., when you close the door with the window up, the window moves up a little bit after the door is closed to seal it all up -- at times, it would undo that on it's own. If memory serves, the passenger side mirror would move on it's own too. The dealer ended up doing a software update and that fixed it...
[/quote]

Yes, that seems to be what it's doing. I haven't noticed any issues with the mirror.

Thanks for the suggestion--I'll mention it to the service guy at the dealer and see if this is an option.