Central Locking issue
02-14-2022, 10:00 AM
#1
Member
Thread Starter
Central Locking issue
Hi, my 2008/9 C Class W204 Sport model has just begun to give an issue with the left side front door not unlocking or locking with the remote key fob. This is a R/H drive UK model so its the front passenger door. When I press the key fob to unlock, all doors and trunk except do so the front left. Similarly after I have unlocked it manually by pulling the inner door release, it won't then lock when I press the key fob again.
This is the first real issue I've had with the electrics since buying the car brand new in December 2008. Has anyone any ideas of the cause and is it a relatively easy fix?
Thanks
This is the first real issue I've had with the electrics since buying the car brand new in December 2008. Has anyone any ideas of the cause and is it a relatively easy fix?
Thanks
02-15-2022, 02:31 AM
#3
MBWorld Fanatic!
Does the front passenger door lock and unlock when using the switch on the door itself?
Does it lock with the rest of the doors when the speed increases from a standstill?
Or does it only fail to lock and unlock with the remote key fob?
If the problem is only with the key fob, then it is not a problem with the door actuator.
Have you scanned for codes? A scanner that can read codes from all modules is needed, not just engine and emission systems. The problem could be in the rear SAM, or the door control module (N69/1 on euro models if I read correctly), or somewhere else on the interior CAN.
The common problem is the door actuator motor. That is a doable but difficult DIY fix because the door trim, interior panel, window, window motor, structural door liner must all be removed to get to it. Almost any other cause of doors not locking or unlocking is easier to remedy. You want to be certain it’s the actuator before starting.
Here is a video of diagnosis of a W204 similar to yours (I think)
https://m.youtube.com/watch?v=3AoHgASxu5Q
Does it lock with the rest of the doors when the speed increases from a standstill?
Or does it only fail to lock and unlock with the remote key fob?
If the problem is only with the key fob, then it is not a problem with the door actuator.
Have you scanned for codes? A scanner that can read codes from all modules is needed, not just engine and emission systems. The problem could be in the rear SAM, or the door control module (N69/1 on euro models if I read correctly), or somewhere else on the interior CAN.
The common problem is the door actuator motor. That is a doable but difficult DIY fix because the door trim, interior panel, window, window motor, structural door liner must all be removed to get to it. Almost any other cause of doors not locking or unlocking is easier to remedy. You want to be certain it’s the actuator before starting.
Here is a video of diagnosis of a W204 similar to yours (I think)
https://m.youtube.com/watch?v=3AoHgASxu5Q
02-15-2022, 06:32 AM
#4
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W204 C320cdi
Mines the actuator 
press the button on the top of the door to lock and pull handle to unlock, two doors are doing it
until it happens to the drivers door I’ll just put up with how it is at the moment
press the button on the top of the door to lock and pull handle to unlock, two doors are doing it
until it happens to the drivers door I’ll just put up with how it is at the moment
