DIY: 996 Door Latch Replacement [Detailed]
#31
Intermediate
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I'd guess that the lock drive motor is faulty on your replacement unit, pulling down both units when plugged in. Your original unit has a faulty microswitch that stops the window dropping. If you are handy with a soldering iron, you could probably make one good unit out of the two, by removing the microswitch from your replacement unit and replacing the faulty switch in your original unit. Otherwise, return your replacement unit for a good one.
#32
Rennlist Member
Join Date: Apr 2010
Location: Ormond Beach, FL
Posts: 5,936
Likes: 0
Received 1,187 Likes
on
759 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
^^ I have to agree. The door latch mechanism is a go or no go situation. If a brand new unit doesn't work right, it never will. What type of replacement door latch did you get? From where? Is it the correct door latch, because there are different ones for driver/passenger doors (and I think LHD or RHD is a criteria as well).
#33
Instructor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
2nd new unit from sonnen Porsche had the same behavior. I had a separate thread asking if anyone knew if there was a difference between part numbers (big price difference). No real responses. I guess I know now.
#34
Intermediate
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
As an example, the left hand unit for a RHD car will fit, but not work in a LHD car. If you have the original unit out of the car, take note of the part number. If you are substituting a VW part for the Porsche part, only the first 3 characters differ. The last part of the part number should be the same.
See my post above.
#35
Instructor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Mine is definitely a LHD car, but it has a different part number than those listed earlier in this thread. I tried the one that was listed here, but it didn’t work. It was less than half the price that my model #. Mine is 3b1837016p. As far as I can tell, there is a vw part with the same part number, less the p. The Porsche part varies from $350-450. I just ordered a used one from eBay. If that fails, does anyone think the vw part will work?
#36
Intermediate
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Mine is definitely a LHD car, but it has a different part number than those listed earlier in this thread. I tried the one that was listed here, but it didn’t work. It was less than half the price that my model #. Mine is 3b1837016p. As far as I can tell, there is a vw part with the same part number, less the p. The Porsche part varies from $350-450. I just ordered a used one from eBay. If that fails, does anyone think the vw part will work?
![](https://cimg7.ibsrv.net/gimg/rennlist.com-vbulletin/529x531/image_065bf2dc51813e8b2db4f59e139343668067d681.png)
Extract from PET for 996
In my case, the units I replaced were 8N2 837 015 and 8N2 837 016 on my '99 Boxster, and 8N2 837 016 on my '02 996 - my cars are Right Hand Drive (Australia). My Boxster had an after-market alarm system, so wasn't using the Porsche Alarm System and the VW units worked perfectly. My 996 does have a Porsche Alarm System and the drivers side VW substitution works great, but I haven't yet needed to replace the passenger side unit, so I don't know if the original unit in mine is the 8N2 or the 3B2 variant. I may also have the same issue as you if/when I have to change the passenger side unit. I get the feeling that the VW unit with the same part number (minus the letter) should work fine (and I would personally try one of those before paying the Porsche tax), but it is only a guess as I haven't had direct experience. Sorry I can't help further.
#38
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
...
And finally, the door latch is truly an electro-mechanical mechanism. It does not work without power. Playing with it on the bench, locking and unlocking, I'm telling you it does not lock or unlock simply by turning the lock cylinder pin. I always thought that the key would operate even if the car was dead (no power). I am telling you for certain the door latch mechanism will not physically lock or unlock without power.
...
And finally, the door latch is truly an electro-mechanical mechanism. It does not work without power. Playing with it on the bench, locking and unlocking, I'm telling you it does not lock or unlock simply by turning the lock cylinder pin. I always thought that the key would operate even if the car was dead (no power). I am telling you for certain the door latch mechanism will not physically lock or unlock without power.
...
Last edited by hardtailer; 08-17-2019 at 06:41 AM.
#39
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Thanks
#40
Intermediate
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The information was applicable to the 996. 2009 would make your car a 997, wouldn't it?
The chances are good that there is an equivalent VW unit for the 997, but I couldn't say for certain. Get the original part number from the 997 PET and try searching the internet for parts that match the last part of your part number. If you find an alternate, just make sure it is for the correct side and for LHD (assuming your car is LHD). It may well be that the 997 uses the same units as the 996, but as I don't have a 997, I haven't checked.
The chances are good that there is an equivalent VW unit for the 997, but I couldn't say for certain. Get the original part number from the 997 PET and try searching the internet for parts that match the last part of your part number. If you find an alternate, just make sure it is for the correct side and for LHD (assuming your car is LHD). It may well be that the 997 uses the same units as the 996, but as I don't have a 997, I haven't checked.
#41
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Great thread - Thanks for all the information and detailed steps - My problem has been resolved after following these steps to replace the passenger lock assembly. After doing this once if the other side fails I will use the VW part as it was easy to switch the piece from the old lock mechanism to the new lock mechanism. I had purchased a used part off fleabay but in the future I will order the VW part.
![burnout](https://rennlist.com/forums/graemlins/burnout.gif)
#43
Track Day
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I have replaced both of my door latches. It fixed the window dropping issue, but now I can’t lock the car. It sounds like it locks, unlocks and then honks and stays open. The latch doesn’t want to turn over. Any idea what this could be? I already checked everything, and it looks like it is all connected.
The following users liked this post:
hardtailer (02-19-2023)
#44
Track Day
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Just replaced mine too...bought off eBay and works awesome. Actually helped the door align better...interesting.
One word of caution (wisdom)...inside door is sharp...not wearing gloves, slipped when pulling something and slit my hand wide open. you can imagine my wife's joy...
Actually had my daughter drive me to urgent care for 3 quick stiches. Oh, and yes, works perfectly now...the door latch that is.
One word of caution (wisdom)...inside door is sharp...not wearing gloves, slipped when pulling something and slit my hand wide open. you can imagine my wife's joy...
![Roll Eyes (Sarcastic)](https://rennlist.com/forums/images/smilies/rolleyes.gif)
#45
Instructor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
OK, I have not seen this discussed here. I replaced the passenger door lock actuator because the window was not going down when opened (window regulator was fine). The new one functions well in that regard, however, now the doors won't lock. If I disconnect it, The driver door will lock. As soon as I reconnect the harness, nothing happens when I hit the lock button on the dash or the key. I disassembled everything and reinstalled it to the same effect. Thoughts?
Has anyone seen that?
I think I'm going to order a replacement, plug it in, and verify I don't get a fault before I actually install it.