I went to the store to get some milk in my '02 ML320 and when I came back I couldn't unlock it with the key. None of the buttons worked so I put the key in the keyhole and turned it, that worked, but next thing the alarm is going off. I tried again, nothing. I opened the door, the alarm went off again and tried to start it. It worked. But the key still does not work. The other key at home does work. Anyone know how to fix it or what happened? It's kind of odd, it worked to lock it before I went in but when I came out it wouldn't.

Mercedes also called me (at home) and my wife said they thought someone stole the car (luckily she knew I had problems, I called her before).

 

Loose battery? Try opening it up and take out the battery and put it back in.

Out of sync with the computer? I think there's something in the manual about the remote going out of sync and how you can resync it.

Hope this helps.

 

Likely you might have corroded batteries because your remote might have gotten wet by accident. Either that you might have loose batteries. In most cases, the remote doesn't loose sync with the internal locking system so I don't think that might be the problem. If changing the batteries doesn't work, then you might have to ask the dealer to give you a replacement one.

 

I have similar problem before and I tried replacing the batteries and re-sync according to the manual. Result both failed.

I end up solving the problem by a ghetto way of disconnecting the car battery and let the computer reset itself

Give it a try ...


D.L.

 

Thanks. I opened the key and the battery looked likeit was in there fine so I went and re-synched the key and that worked.

Thanks