issue : elec window motor not-stopping-at-stop-position

Sorry if this is a previously-answered question, had a look with the search feature but whilst could find threads about resetting the stop positions or replacing the regulator, couldn't find the answer to this. My driver's side window is ignoring the top & bottom stop positions, if I let it the motor runs until the window is fully hard up or hard down, when it makes a godawful clattering noise as the motor is still running but the window can't move because it's fully up or down, so the teeth on the motor are jumping across the teeth on the regulator (and I've had it apart, the motor tooth plastic is obviously softer than the regulator, so the motor teeth are wearing-off, yuk !) Full history 2010 Cayman 987.2 first half of last year, had to replace the regulator : window wouldn't raise or lower, clattering noise so had a look in the door and found the cable had frayed and snapped so fitted new regulator which was easy enough following youtube videos, getting the door card off was the worst bit all worked fine, window went up and down; obviously window memory of up & down stop positions had cleared so I used the reset feature of winding window fully up and fully down to its limits so it 'remembered' where they were : worked fine, great ! all worked fine for 8 or 10 months : window dropped on opening door handle and raised on closing door just as it should, window went up and down using one-touch just as it should, it stopped at the bottom and at the top but a few weeks ago, went out in car and then when getting back in and driving home was aware of 'window is open' wind noise so pushed button to one-touch raise it and sure enough wind noise stopped as window closed but then got this godawful clattering noise until I reacted by pushing button again to cancel the one-touch closing now, when I open the door the window drops fully 1 1/2" but doesn't lift back up when I close the door if I use the one-touch on the window in either up or down, the window moves but the motor doesn't stop running when the window hits its physical limits of fully-open or fully-closed, motor keeps running. this godawful noise as teeth jump on motor against regulator, until I hit switch again to cancel the one-touch so I can open and close the window by manually nudging it up & down on the switch, not using one-touch, and I can do this to close the window fully when parking so car is useable but obviously this is a pain if I've forget to close the window that 1 1/2" a couple of times before parking or worse, I've forgotten about it and allowed window to go down fully using one-touch, when obviously every time the teeth jump, it's wearing them out I've had it all apart again, taken glass and regulator fully out and refitted it all back again, couldn't see anything awry, but it's no different, it still does it I can see that the teeth on the motor are being worn-off, as the plastic must be softer than the teeth on the regulator and I even disconnected battery for half an hour to see if a reset would make any difference : it 'forgot' the positions on the passenger window and I had to reset them, but driver's door still doing this Any ideas ? Where are the sensors for the window stop positions, which should cut the motor when it hits the full-up and full-down positions : are they on the motor assembly itself ? thanks

There is no discrete "sensor" for the window stop positions, it's done by the module that controls the window measuring the current going to the motor. When the window hits the fully open or fully closed position on a properly working window regulator, the motor stalls and the current it draws immediately increases. The module knows that the increased current draw indicates a stopped window (this also works for the anti-pinch safety feature.) In your case - since the motor has worn teeth it never stalls when the window is fully up or down, so the devices measuring current doesn't see the increase in current draw and doesn't know to turn off the power to the motor. Short answer to fix it: Replace the motor or if possible just the gear on the motor. It's kaput. Gone. Dead. Of no use. I have no idea if the gear is available as a separate part, but there might be someone out there making aftermarket ones as replacements if the failure rate is high enough. I know they make them for the convertible top gear-set. I'd search Amazon and eBay. I'm assuming the new regulator didn't come with the motor, that you reused the old one. It was already worn when you moved it to the new regulator - now it's worn out. When you replace it use a good quality lithium based grease on the gear-set, it will work faster and last longer that way. HTH,

OK, that all makes sense Don, I kindof feared that was the case. Thanks for the reply.

Unfortunately the part doesn't have a unique number in the parts list. Hopefully somebody makes an aftermarket version (or you could get a motor cheap from dismantler).

That's useful, thanks I've started looking for a replacement unit from a dismantler - worry is that I could replace a worn one with another one, but hey Your diagram has the part number, but online I'm seeing people quoting different numbers and claiming the part will fit a Booster , Cayman or 911 of my year - I'll take my doorcard off again and look at mine when it's next a decent day : should be easy and quick as I've just put it back temporarily with the bolts but not the clips (no rattles or squeaks or increased noise )

Let us know what you find out. I wonder if there is a (cheaper) Audi /VW part number that is basically the same.

Oh, and if is just the last digit of the part number that changed, that is a revision. Higher numbers mean newer design. The part number is from a 2012 parts manual so it may have been updated in the last 9 years.

That would be the first solution I would pursue. It's extremely likely they have the same part with their own numbering system and at least half the price.

incidentally, not sure I understand the part numbers & 'remarks' on the parts list above it has 'power windows' with different part nos .075 and .076 with remarks /L & /R : OK fine, I'd call them the regulators myself but that's the left & right but it also has the same part number 997 624 181 02 electric motor with remark /LL/L and then listed again with 'remark' /RL/R and same part number 997 624 182 02 electric motor with remark /LL/R and then again with remark /RL/L if /L and /R are left & right, what do /LL and /RL signify ? and how can same part number be /L and /R ? I'll leave driver's side and passenger side out of it, call it left & right, as I'm in UK and you're in USA and the driver sits on the other side But just a quick look on eBay here in the UK shows people selling 181.03 as a left, with a date on the sticker which I assume as mfg date in euro-format 06/12/06 181.03 as a left, 08/12/05 182.03 as a left, 05/04/06 182.04 as a left, 24/08/07 181.06 as a left, ??/10/09 181.06 as a right, 17/09/09 182.06 as a right, 13/09/11 If the date is a mfg date, then yes .03 .04 .06 are revision numbers - but is 181 or 182 a left or right ? The parts actually look identical, left & right - unlike those for a 981 where left & right are mirror images of each other So are they physically the same part, fitted the opposite way in the left & right doors (ie facing towards front of car or back), where the up & down switches on each door are wired opposite to tell the motor to wind clockwise or anticlockwise ? Hmmm....

And a bit of googling around - the ones from an Audi A3 appear to be physically identical (both Bosch of course) and are ridiculously cheap compared to Porsche bits - except they appear to have rather less pins in the electronic connector.... ...which is not to say that those pins actually do anything in my car of course ! I guess it would be very easy if I had a Cayenne or Macan

I looked and my parts pdf doesn't have a key so I'm not sure. I should stop this post right there (but, I'm an engineer so I won't). Take the rest of this as pure speculation. If I had to guess, and it is only a guess, is that it has to do with right hand drive vs. left hand drive. Obviously in this case that is an important distinction. The drivers side controller (which is also contained in this assembly) has additional pins because it is has more signals to handle (the switch in the drivers door controls both windows for example). That may explain why you saw a difference in pin count. I also googled one of the part numbers and it came up as "left side" in the US and "right side" from a UK site Best to check with a local dealer!

I wonder re. RL/L, LL/R, etc right and left in German are rechts und links and right-hand drive is Rechtslenker, left-hand drive is Linkslenker (Google translate is wonderful, I vaguely knew this and it was one of those thoughts you have in your subconscious which eventually forces its way out - Google confirmed when I looked it up) - so I think /RL/L is right-hand drive, left door and /LL/R is left-hand drive, right door etc That would make sense in that LHD left door and RHD right door are both driver's door and are both part 997 624 181 02 And LHD right door and RHD keft door are both passenger door and are both part 997 624 182 02 Which accords with what you found, part being 'left' in UK and 'right' in US However that doesn't explain the part numbers I saw on sale on eBay above, where 181 & 182 seem to be fitted about equalltyto each side Most sellers are breakers yards not private sellers, so you'd hope they'd get it right (and here in UK we might see the odd LHD car being broken but it would be a rare oddity and they'd be sure to point it out) - but looking at the pictures, the 181 has more pins, the 182 has less I've decided I want a 181 - but I'll take the door inner panel off and have a check !

Update (I hate it when you have a search to see if your question has been asked before, find it but there's no answer and you can't see what solution the other guy had !) After a bit of thought I decided the issue was not with my motor at all - it was with the regulator. The motor actually works fine, it makes the window go up and down, it's not like the motor has died. The regulator however is what I had replaced - the factory one broke (cable corroded and snapped) so I fitted a replacement : not a ££££ (I'm British ) factory one but one which was labelled as 'OEM' and was still significantly expensive rather than cheap rubbish, but rather less pricey ££. Quality appeared as good as the original and it worked fine for 6 or 9 months (albeit with covid restrictions meaning not that much travelling about...) Then it started with this issue where the motor didn't stop at the top & bottom of window glass travel, when the glass hit its limit the motor kept running and the teeth of the motor were jumping on the corresponding teeth of the regulator. However, if using the window switch manually to keep away from the top and bottom limits and avoiding the one-touch up and down, the teeth still mesh and the motor drives the regulator fine. I took the door card off again and found that my part is indeed a 181 (NB it's a RHD car here in UK, so this is driver's door - but am still seeing people selling both part 181 and 182 as fitting the left and right doors : now I can see that maybe 181 can be fitted to the passenger door as well and maybe have some redundant features [eg driver's door has switches for both windows but passenger door only has one switch for that window], but I don't understand how 182 works both sides...unless maybe it was originally two models but Bosch rationalised production and just made one and badged it as two...dunno) They way things work is that there is a conical plastic toothed male cogwheel on the motor, which fits into a corresponding toothed female plastic cup-shaped cog on the regulator. On investigation, I found that this female cup-shaped cog is a bit loose in the frame of my regulator, so rather than just rotating and pulling the cable and moving the window up and down, I think when the glass hits the stop it was moving back a tiny amount and meaning that the two sets of teeth could now slip against each other - and the plastic of the motor cog is softer than the regulator cog plastic so it's wearing the tips of those teeth off. What I've done - and we'll see if this is a long-term fix - is taken the motor and regulator out and filed a couple of mm off the mounting legs where they bolt together the motor is inside the door inner panel and the regulator is on the other side of it, there are 3 bolts going through from the motor, through the panel and into the regulator, pulling the two together and fixing them to the inner panel so I've filed (plastic - easy) just a couple of mm off both the regulator and the motor where these bolts go, so that the two are pulled that bit tighter together. It seems to work, the motor now stops when it should, the one-touch works fine and the window stops when fully up / down, the auto-lift of the glass to seal into the doorframe works when you close the door. As I say, we'll see if this is a long-term fix.

Thanks for sharing your (hopefully) final solution. I wish everybody updated their thread with the answer!

This post was a life saver, thanks. Had exactly the same problem. Just knowing how the limit worked made everything clear, thanks deilenberger . I fixed mine by "tightening " the gear meshing by wrapping about 5 layers of plumbers PTFE tap over the motor gear to take up the slack. Its a sort of viciuos circle isnt it ? Gears wear, motor skips, gears wear some more, motor keeps going. Lets see if it lasts.