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Key will not ARM/UNARM (Lock/Unlock)

3593 Views 15 Replies 6 Participants Last post by  BMAN
I have a 1997 E320 with two keys. Just the other day, I could not lock the doors with either key. Figuring it was the batteries, I changed them in both and yet it still will not lock. I can start the engine and drive no problem, but I cannot lock the car!

I have tried turning the key one click (not turning the engine on) then removing the key and that did not work. Not sure how to resynch, but was hoping to avoid removing the battery terminal. Any ideas???

Thanks in advance.

Oh, and if you happen to see my car, please don't steal anything since my doors will be unlocked!!!
1 - 1 of 16 Posts
Do the "Ctrl-Alt-Del" on the car first.

Undo the negative battery cable in the footwell of the rear passenger seat (a small plastic cover is covering it. The cover just pops off with some gentle leverage).

Unhook the cable. Walk around to the driver's side. Pump the brake a few times. Reattach the cable. Go through sync procedure.

I have a gremlin in the system and I can not locate it. The PSE seems to be fine. I think it may be the CAN BUS or something equally as expensive.

My symptoms are the same but I also lose Driver side window and seat adjustment capability.
1 - 1 of 16 Posts
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