Rear door do not unlock
 

The rear driver door doesn't unlock when I use the key remote. All the other doors unlock. I can only unlock the rear driver door using the inside door handle.

But, I can lock the door with the key remote.

Your help would be appreciated

The door mechanism's contain two electric motors - one to lock the door and another to unlock it. Sounds like the unlock motor has failed...

Have a read of this... https://xoutpost.com/bmw-sav-forums/...or-repair.html

Rear door do not unlock
 

I thought at first the two motors were for lock unlock but that is not accurate. One motor for lock and unlock the other for disable/enable. (aka double lock).

If you can't unlock it usually means the disable motor is broken. Often you can get it to work one more time by using the emergency egress method of lock the doors with remote or key outside then while holding the central lock button pull the door handle twice. (be prepared to silence the alarm).

The symptom you are describing where it locks but won't unlock with the motor just means the primary lock motor is shot. Most people replace the whole door lock actuator when this happens. I just replace the $6 motor when this happens.

There is a minor misstatement in your original post prob just because being brief in the title but had me misdirected.

The door will unlock just not with the motor.

It's more common for the lock/unlock motor to fail in such a way that it will lock the door but not unlock the door.

This is the most common symptom of the motor failing and also you can often get the motor to unlock the door some times eg lock and unlock the doors a few times it may work one out of 5 times.

Get the part fixed or replaced before the double lock motor also fails or you will not be able to open the door.

Ok, thanks.

What you are saying is I need a new door actuator?

Or repair the one you have.

The motor that locks/unlocks is the first to go usually.

You need Item 1, here, https://www.realoem.com/bmw/enUS/sho...diagId=51_7770



The Door Lock Actuator is a polarized thing, when the + and - are one way the actuator locks, the other way makes the actuator unlock. The lock and unlock coils can fail independently of the other, this would give you a lock that locks but won't unlock. The polarity of the power is decided by the body control module (there's a name for this item that I don't recall). It's also a possible variant that there are three wires to the actuator, and when wires 1 & 2 are used, the lock locks, and when 2 & 3 are used then the lock unlocks, the affect is the same, you can have an actuator that locks the door but will not unlock it.

(The diagram I gave you is from an '05, you should click the part number to pull up the cross reference list to see if the same part is used on your car.)

When the actuator fails, you can still manually lock and unlock the door(s) by pushing the lock down, and by pulling the door handle.

A bit of a distinction without a difference but that is not an accurate statement.

The lock and unlock is performed with the same motor that has voltage applied in opposite direction. For some reason however the brushes wear or whatever, The motor will stall in the unlock direction where it’ll still work in the lock direction near end of life. eventually it won’t work in either direction.

There are no coils involved in the lock mechanism other than I suppose a hall effect coil that is measuring the position of the lock.

Functionally the defect acts as described why I said A distinction without a difference

I accept the distinction. I described a solenoid operation, not a motor. I haven't physically done this job on my E53, but I replaced the door lock actuators that were basically solenoids.

(I have a brand new door lock actuator that is a solenoid laying on my bench. If anybody wants it. send me $20 and I'll drop it in the mailbox to you. I don't even want the money, but I also don't want to cover the postage, so you pay postage...)