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Central locking issue - can't unlock three passenger doors

NTVZCOMMY

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Hi guys,

Hoping someone might have an idea what is wrong with my car. My VZ's central locking is not working correctly. The drivers front door unlocks and locks fine, but be 3 passenger doors will not unlock. You can not unlock any of them with either the remote central locking, or manually with the key in the driver's door or even by the lock tab on the door so I am unable open any of those the doors.

Things I have tried after researching around the net.

1. Replaced the front drivers door actuator with a new one
2. Replaced the ignition key remote central locking tab with a MAP brand key and bought the encoder also recoded it myself. The key works perfectly now. It's fixed the engine immobiliser issue I've been having because my old key was playing up.
3. Turned off the 2 step unlock function in the control menu
4. Found a procedure for a BCM reset, followed the instructions but not sure it actually worked. I still did the idle relearning process after attempting the reset.
5. Found a procedure to turn the central locking function on or off. You had to turn the ignition a few times and press the unlock button 3 times between each step. I couldn't get the vehicle to sound the horn which the procedure said should happen when the sequence was completed correctly.

My central locking worked perfectly then one day the 3 doors just stopped unlocking. When you keep pressing the remote unlock button the first click will unlock the driver's door and the second click just makes the indicators flash twice instead of unlocking the 3: passenger doors.

Before I shell out for a replacement BCM Module would anyone have any suggestions or tips/instructions on how to properly do the module resets, or other things to check or try i.e like info on how to control the central lock functions like turning it on and off by following a specific sequence of button presses and key turns to access it. I am stuck for ideas, I cant find any info anywhere to fault find and fix what ever the issue is causing a 3 door lock failure, the only stuff I can find all related to just or 2 doors and I'm thinking the 3 door fault might be might be something a bit more Major than the 2 door fixes. Just like to exhaust all my options before I just keep chucking money at buying parts and gradually replacing each part of the system with new stuff.
 

petern64

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I'm guessing you have tried disconnecting the battery for a couple of minutes
 

NTVZCOMMY

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I'm guessing you have tried disconnecting the battery for a couple of minutes
Yeah bud. Had the battery out of it for 4 hrs when I did a spark plug change about 2 weeks ago
 

NTVZCOMMY

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Fu Manchu

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Sounds like they are dead locked too.

Don’t get a new BCM. The BCMs are repairable. There are relays in them that control the doors. They can be replaced. You can do it if you are handy at small soldering.


I did have schematic of the internalsof the BCM somewhere after looking at central looking issues on mine.
 

NTVZCOMMY

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Sounds like they are dead locked too.

Don’t get a new BCM. The BCMs are repairable. There are relays in them that control the doors. They can be replaced. You can do it if you are handy at small soldering.


I did have schematic of the internalsof the BCM somewhere after looking at central looking issues on mine.
Awesome that'd be great thanks champ. I'm fine with circuit boards and soldering. And yeah man they all went deadlocked. I assume somewhere in the circuit the line that triggers the other 3 doors is not getting power from either the BCM or an issue along that wire
 

Fu Manchu

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Screen Shot 2022-02-17 at 12.28.47 pm.png

You can see there are a few relays that control the doors and their functions. (right hand side of the diagram)
The BCM is easy to remove. The BCM is easy to open.
I guess a good idea and opportunity to replace all the relays on the board so you don't have problems later as well.
 

NTVZCOMMY

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View attachment 233738
You can see there are a few relays that control the doors and their functions. (right hand side of the diagram)
The BCM is easy to remove. The BCM is easy to open.
I guess a good idea and opportunity to replace all the relays on the board so you don't have problems later as well.
Cheers for that bud, will rip it out on my next days off. The schematic will help heaps. Thanks mate
 
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