Door Only Unlocks 50% of the Time

[kennethsime]

About half the time I lock/unlock my car, the rear passenger door doesn't unlock. The other half of the time, it unlocks but only part way.

Lately, this seems to have manifested in a condition where the rest of the car thinks it's unlocked, but perhaps that door doesn't think it is, and the alarm goes off when I try to open another door.

Does that sound familiar to anyone? I don't think it's the door latch, because the door does open just fine from the inside each and every time. Seems like an electronic issue, maybe the door's wiring harness?

 

[P2B]

Yes, sounds familiar. In my case it was a busted wire inside the bellows between the door and the b-pillar. A couple more had cracked insulation and were getting ready to fail. I stripped and soldered all suspect wires, wrapped them in electrical tape, then taped a short length of solid copper wire over the joint to move the flex point away from the repair.

 

[Drewmeister]

It does kinda sounds like the door latch to me, or specifically the power lock part of it. I had similar things happen, along with "implausible" codes set for the RR door lock in the central locking module. For me it was usually the door not locking/unlocking (or only partially unlocking) when locking/unlocking all doors. The only time I'd set off the alarm was when it was "armed" by locking via the remote (but the horn wouldn't sound if the door didn't lock) and then opening the unlocked-but-should've-been-locked door. Locking or unlocking manually always worked.

I took out the latch, disassembled and lubricated the mechanism. There was a chunk of hardened, dried grease that fell out when I opened it, which may have prevented it from operating smoothly. It's definitely easier to operate manually now, and the power lock motor has worked perfectly ever since. Of course now that I've fixed the RR door, the LR door is acting up in the same way...

A bit of a pain to get to though, at least on the rear doors, since you first have to remove part of the window seal and the divider bar, and then the window glass, before removing the whole carrier assembly that everything is connected to.

 

[kennethsime]

Well, I haven't tried to fix it yet - too busy with other stuff, and honestly the only time I've ever removed a door panel was on my 1993 Ford Ranger. Always time to learn something new, but it'll probably be next month.

Thank you both for your insights! I'll report back once I've tried something.

 

[KrashDH]

Well, I haven't tried to fix it yet - too busy with other stuff, and honestly the only time I've ever removed a door pane was on my 1993 Ford Ranger. Always time to learn something new, but it'll probably be next month.

Thank you both for your insights! I'll report back once I've tried something.

It's a pretty easy repair. I just got done doing both my driver side front and rear doors. The rear is a bit more involved because of how VW chose to "secure" the window to the track bottom, as well as you have to remove the window guide which can be a pain to re align during assembly

 

[oilhammer]

Sounds like a bad latch to me. Very common. Between my VAG cars' 20+ doors, and all my customers' cars, there is rarely a week that goes by that I am not replacing a latch on something.