BMW Locked Door


90 535i BMW. Passenger rear left door lock will not open. All other elec. locks open and close properly. Is this a simple regulator inside of the door panel? Any help will be welcomed.


Power door locks are controlled by actuators which have power alternating from one side to the other depending on switch application.

The wiring to the door from the body may be damaged or deteriorated stopping power from reaching the lock actuator.

The lock should open with your key. Once open, remove the inner panel and carefully remove the plastic moisture barrier to gain access to the actuator.

Once there, you can test the connections for power (with a light probe or multi-tester) by having a helper activate the power lock switch.

One side for lock and the other for unlock.

If no power you will have to trace the wires back toward the switch, testing at intervals.


huh? passenger rear left? which one is it?


Can you open the door? (By manually pulling up the lock knob?) If so, you can either live with it that way or take off the door panel and check for power, etc, most likely ending up replacing the lock actuatot for about 100 bucks.
If you can’t open the door, there is a procedure BMW has come up with for just this eventuality. You have to free the top of the door panel by pulling up on it, not easy with the door closed. When you get a little space to see down inside the door, look for the lock actuator, and the white plastic ‘piston’ on it. You take a long screwdriver, place it against the white part of the actuator, and rap it sharply with a hammer. This breaks the connection between the actuator and the lock and you can operate it normally, open the door, and repair it, or just live with it.
If this sounds like something you should let a mechanic who has done it before do for you, yes, it is.


It’s going to have to be gone into by removal of the door panel first. It could be something simple such as a lock rod coming loose (common on just about make of car) or possibly a lever hanging up on the latch assembly.

In the event a plastic retainer clip is broken (common on most cars) this is easily repaired and in the event a plastic clip is not available, I’ve had real good luck by using spring steel carburetor linkage clips which are available at most parts houses. (And they’re good for the duration too.)

Old grease on the latch combined with dust really thickens up and this can cause the latch assembly to bind. A visual inspection should determine this and if it’s the case, aerosol carb cleaner should free it up.


Just to clarify my earlier post: It is not possible to remove this panel (non-destructively) with the door closed. You can however get the access through the top that I described.


Clean slipped my mind while thinking about the problem. This may require a Slim Jim to open the door so that means a trip to a locksmith, a body shop, or possibly an understanding cop.
One could then wedge a rag over the striker plate on the door jam (the door will be ajar a bit of course) and rope the door shut until you get home; if this is going to be a DIY deal.