I have a 2014 Mercedes GL350. When I get up some mornings, the windows are down, sunroof open along with back door hatch. Someone's remote has the ability to unlock my car. How can I change my key fobs to respond to a different code?

  • Welcome to Motor Vehicle Maintenance & Repair! Oct 27, 2020 at 19:11
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    The most likely reason is that the unlock button on your remote has been accidentally held down for long enough (keys squashed while in your pocket or accidentally sat on etc.) to activate the total open/closure function.
    – Andy Hames
    Oct 28, 2020 at 12:40
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    Agreed with @AndyHames. Sounds like a malfunctioning fob or it's being physically pressed for too long when you're not aware. Do you hang your keys up on the wall or leave them somewhere they are prone to presses such an in a purse or simply somewhere easily accessible by a cat/dog/child?
    – MonkeyZeus
    Oct 28, 2020 at 19:42

2 Answers 2


Its not possible to reprogram the keyless code on your key but it IS possible with a mb tool to have all the keys disabled except the key your using or if you really wanted you could get a new unused key from a locksmith or dealer and then disable all the other key spaces so you could be 100% sure there is no trickery with old keys.

That said, It is highly unlikely with the system these keys use that someone else has a working key unless you have recently lost one.

More likely you have some issue's with your own remote, the controlling module for locking systems or keyless entry, or the door lock actuator itself is failing and thinks its being held in the unlock position sometimes (makes most sense since all windows are open). I'd take it to a mb specialists or dealer and have it checked out first instead.

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    I'm thinking the body control module (BCM - or whatever MB calls it) is having an issue. Agree with your assessment of going to a MB dealer to get it sorted ... not going to be cheap, though. Considering how many codes there are for the secure interface (literally billions if not more) it seems nearly impossible (with a five-nine improbability) for someone else to have the same code as the vehicle. It would not have come from MB with a duplicate as they track that stuff (along with every other car manufacturer). Oct 27, 2020 at 19:16
  • Or the kids are playing with the remote...
    – Solar Mike
    Oct 28, 2020 at 9:58

One maybe less plausible explanation is that you leave the fob fairly close to a door or elsewhere, and a computer a radio amplifier and another radio module can extend the proximity unlock and ignition/start on the vehicle permitting the window opening from the inside.

I find this beyond improbable considering no prankster would keep doing this more than maybe twice, let alone day after day risking criminal trespass charges, arrest and jail time — would be more probable if this happens, that you don't find the car in the morning.

However, technically, it is not impossible.

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