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Tailgate unlock failure started after remote central locking stopped working from keys without any warnings.
Replaced batteries but neither key will accept reprogramming so using emergency to open via drivers door and start the vehicle so chip in keys must be OK.
I can lock and unlock all 4 x doors from centre console but tailgate will not unlock.
Have to climb over back seat to open from inside.
Have replaced the outside handle _ 1635402332 _ 2nd hand one. But the same issue.
Assistance / advices please.
Last edited by roadhugger; 03-13-2024 at 08:25 PM.
It's a standard problem, I had it when I first got my ML320 in 2013. There is a little white plastic rod bit that when actuated is pulled against the lock mechanism to unlock it and so eventually breaks off. It can be repaired by taking it apart and using a small self tapping screw, but is easier to get a replacement tailgate actuator that isn't broken... The inside trim has to come off, and as usual, the trim clips break, but that is no big deal. I got stuck at that stage as a screw head broke on the outside where a bit of trim needs to come off above the number plate lights, and I couldn't get it out, so stalled... Thus, I made do with locking it from inside with a long thin stick of wood, for about ten years until I got fed up of doing that and a new garage was willing and able to fix it with the tailgate actuator I got off eBay. There were various articles here on MBWorld and on BenzWorld that were very helpful, and on YouTube, but they would need diligently searching for, and a quick look couldn't find them again. If yours needs unlocking, then it might be a slightly different issue, as mine was unlocked all the time and so needed locking from inside, rather than unlocking! If I remember rightly, it wasn't until the trim was off that it was easy to lock from inside. If it locks on the central locking, but won't unlock then that is a little better than never locking!
Thank you Brezelal
I have not been able to work out where this broken part is from your image - is that a picture from the end of the actuator?
Attached is a picture taken today of the handle and the actuator and all seems to be OK.
I have tried a 2nd hand one off a wrecked ML and the same occurs - that is, when wired in, the lock works but not unlock
I am suspecting the actuator may be the problem. Any further ideas please?
Last edited by roadhugger; 03-19-2024 at 12:44 AM.
Hi, If it locks but doesn't unlock, then maybe it is a more basic mechanical issue with the lock itself at the middle of the bottom edge of the tailgate? It may simply needs a good squirt of WD40 into the mechanism?
hankyou Brezelal,
I forgot to mention all the testing processes
Have used spray on all moving parts - OK.
I can lock the actual latch (at bottom of door) manually and unlock manually. so tI believe hat mechanism is all good
With the tailgate open, and looking at the assembly, and the handle / latch assembly in unlocked position, I can see and hear the actuator activate and pull the lever to locked position.
But then when I try to unlock with the console control, noting happens. Remains in the locked position.
That's why I suspect the BOSH actuator may be faulty and the 2nd hand one I got seems to be the same.
Trying to test the actuator in position with a meter, does not provide a stable voltage
Is there any test procedure likely to be available anywhere please?
The piece that breaks goes from the "accordion" actuator into the black plastic piece. I screwed a small screw with the proper size head into the accordion area and fixed mine.
03-13-2024, 08:20 PM
