[Stevie707]

Hello!

I've owned my 2016 335i GT for about 2 years now.

For about the last year, my rear passenger door will not lock/unlock properly. I've replaced the actuator in the door twice now (a very frustrating procedure since I have fat hands).

I think it's worth noting that in October of 2021 that same door was backed into in a parking lot. The damage wasn't severe, though the door was disassembled and reassembled a number of times since the glass tube that lights the door had been shattered from the accident, and the shop it was fixed at wasn't sure what exactly was wrong with the light.

I'm just at a loss as for what is wrong with the door actuator(s) I'm on my second replacement and it has started malfunctioning again. It works fine in warmer weather, but after a few weeks sitting in the cold, it has stopped working properly... Again.

I'm just lost as to why this only occurs in cold weather, and wondering if it's a fuse issue, or worse yet a wiring problem. Any suggestions are very much appreciated.

Thank you!

[Billfitz]

A fuse is either good or bad, there's no in between. The same applies to wiring. Temperature wouldn't affect either. Temperature will cause water to freeze, so if they didn't seal the door and water is getting in there that might explain it. Have you scanned for codes? That's the first step with any diagnosis.

[Stevie707]

Originally Posted by Billfitz

A fuse is either good or bad, there's no in between. The same applies to wiring. Temperature wouldn't affect either. Temperature will cause water to freeze, so if they didn't seal the door and water is getting in there that might explain it. Have you scanned for codes? That's the first step with any diagnosis.

I have scanned for codes, none have been appear yet. As far as I know, the door is never really "weather sealed" where the actuator is located, because the window sits in the same place inside the door panels, which as you know, can introduce moisture to that environment. If moisture could be a problem though, I have a feeling the wiring connection could be going out and needs to be replaced as well.