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Discussion Starter #1
Today when I went to unlock my 540i, I noticed that only the rear doors unlocked. I locked it again, unlocked it, and the same thing happened. Then, I went to roll down the windows using the driver's door controls, and they would not unlock. The automatic function on the sunroof also stopped working. Then, in an attempt to get the passenger door unlocked, I went to use the central lock button and it did not work. I had to get the driver's door unlocked using the key and twisting it all the way- the key did not trigger the lock/unlock function when in the door. Also, the seat memory button is inactive.

Any idea of what is causing this and how to fix?

Thank you!
 

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Any codes?
Battery voltage?
Is your seat power control unit broken?
 

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Today when I went to unlock my 540i, I noticed that only the rear doors unlocked. I locked it again, unlocked it, and the same thing happened. Then, I went to roll down the windows using the driver's door controls, and they would not unlock. The automatic function on the sunroof also stopped working. Then, in an attempt to get the passenger door unlocked, I went to use the central lock button and it did not work. I had to get the driver's door unlocked using the key and twisting it all the way- the key did not trigger the lock/unlock function when in the door. Also, the seat memory button is inactive.

Any idea of what is causing this and how to fix?

Thank you!
Some of what you wrote is NOT an issue...and is working the way the car is designed to perform. These 3 things below are working as designed:
  1. Then, I went to roll down the windows using the driver's door controls, and they would not unlock.
  2. I went to use the central lock button and it did not work.
  3. I had to get the driver's door unlocked using the key and twisting it all the way- the key did not trigger the lock/unlock function when in the door.

Why?
1. If you lock the car using the remote key or the driver's door exterior lock...this sets the alarm siren system (DWA) and also DOUBLE-LOCKS all of the doors AND the fuel filler door. This means that the interior & exterior door handles are DEACTIVATED. (If a thief broke your window they have to crawl over the broken glass to get in & out of the vehicle...they can't just reach in and open the doors. This is also why the owners manual warns NOT to lock people inside the car...once the motion sensor activates, they can't get out of the vehicle until you come back with the key to UNLOCK the car.
SINGLE-LOCK: occurs when you lock the vehicle using the center console button, manually lock the doors using the door pins, or if you have the car/memory programmed to lock the vehicle at a specific MPH. (The fuel flap remains UNNLOCKED)
DOUBLE-LOCK: occurs when you lock the vehicle with the remote key or when you use the driver's door exterior lock cylinder​

2. The same applies for this situation, too. The int/ext door handles are deactivated as well as the button on the center console to lock/unlock the vehicle...if you've armed and double-locked the vehicle...only the key used in the driver's door exterior lock cylinder or the remote will UNLOCK the car.

3. This is the emergency/manual unlock position which is engineered/designed to gain access into the vehicle when there is no ELECTRICAL power. When you turn the key in the cylinder only 45°...you are electronically activating the actuators...when you turn the key 90°, you are MANUALLY locking or unlocking the actuator

It sounds like you either have a low power situation or lock actuators in the front doors that are failing...or the control modules for the front doors have an issue.

The rear doors are under the control of the GM and receive their commands to lock/unlock from it. The front doors are also under the larger umbrella of the GM (due to it controlling FZV)...but the command to lock/unlock is passed off to each doors' control module. This may be the reason why the fronts aren't working but the rears are. Have you done any recent work to the front doors?

 

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Discussion Starter #4
Thank you for the tips! No, I have done no recent work to the front doors. Everything worked great one day and then the next all of this happens.
 

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I am still having this issue, any ideas on what could be causing it?
 

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What codes do you have?
 

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Ignition switch?
 

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Might want to pop off the front door panel and see if anything is unplugged or any wires got messed up in the harness going into the driver door?
 

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I thought that too but it still starts up as normal- the front doors just don’t unlock. The back door still communicate normally with the remote and central locking.


Sent from my iPhone using Bimmerfest mobile app


I’m not sure if it’s the ignition switch, but a failing ignition switch rarely effects ignition. The symptoms are usually weird electrical gremlins. Open and close the vanity mirror slider under the drivers side visor and see what happens.


Sent from my iPhone using Tapatalk Pro
 

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i had the same issue with my 99 528 once, what atobe said in post 10 needs to be checked. fronts are commanded over the p bus, rears are relay controlled from the GM. the Q of knowledge, in his post #3, explains it fully.
 

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Discussion Starter #13
i had the same issue with my 99 528 once, what atobe said in post 10 needs to be checked. fronts are commanded over the p bus, rears are relay controlled from the GM. the Q of knowledge, in his post #3, explains it fully.
I will double check that, thank you!
 

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Discussion Starter #14
Something that stood out to me is "It sounds like you either have a low power situation or lock actuators in the front doors that are failing...or the control modules for the front doors have an issue." I thought it may have been a lower power situation as well since due to the cold weather my battery had drained- however as of the past week or so, I have had it hooked up to my C-TEK battery tender so the battery has not gotten low in the past week or so. My thought would be that a door module has failed, but I do not know which- but what I think really happened is that the control module has an issue. Where is the control module for front doors?
 

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Discussion Starter #15
I did a quick Google search and came up with the part number: 61356904243 for "door module co-driver". Could this be the module giving me all this trouble?
 

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Discussion Starter #16
This link has been a great help! I am thinking that this might be the issue. https://www.bmwgm5.com/PM-BT.htm But, I believe that it might be the driver's door module that is failing due to the fact that the seat memory no longer works.
 
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