After changing the battery, the anti-theft code for the radio has to be reset as well as the windows and door locks. Sometimes the system locks you out and the radio, door locks and windows do not work. Mercedes suggests disconnecting the battery for 30 seconds and if that does not work, letting the car sit for 24 hours with the key in the #1 position. Neither works.
(When I say “do not work” I mean the radio does not come on when you push the power button, nothing happens when you press the window switches, and the door locks don’t operate with either the remote or the switch in the car.)
Any other ideas? Does one really junk their car when the battery dies?
1998 E320
You need to know the code that came with your car when it was bought new. This is typical of modern cars. You must have purchased this car used recently.
The dealer can probably get you the right code, but whoever sold you the car should have passed it along.