My immobilaisor won't reset with the keys

Go on youtube and put in how to reset your car key after renewing key fob battery good luck colin

I have change several new keys which had the magnetic chips in them which had to be sync to the car, . When you have a new key made you have to sync it to the car/ magnetic chip or fob key. Link which might help sync problems with fob keys, my vehicles were GM with just the magnetic chip key and not nearly as complicated.
http://www.benzworld.org/forums/w163-m-class/1318416-remote-sync-key-not-working-sync.html

I think you may have a immobilisor problem try the spare key first

could be in the fuses

Having the vehicle checked for DTC'S - diagnostic trouble code's an doing diagnostic's for the code is the proper way to diagnose , not guessing . No you cant reset it or disengage it ,need factory or professional scanner .

if the security light is on then the anti-theft has been activated and will need to be reset.most shops can reset it for you or you can go to a shop and see if they will let you know how to reset it.make sure the key you use is the original key and not one cut at a store that cuts keys as they are different,

If you don't have a key, replace the lock with one that has a key with it. If you can get it to work with the remote, why not leave it alone. When you replace it with a lockset with a key, you may not get a fob that works with it. It's a catch 22 thing in progress here. If I do this, I can't have that. If I do that, I can't have this.

i believe if you put key in ignition turn it forward and back off twice it should reset the anti theft to start it. or unlock pass door with key and that might reset it. also try the same with back pass door if the other didnt work. hope this helps.

DISCONNECT YOUR BATTERY AND RECONNECT, THIS SHOULD RESET THE BRAIN.

ALSO...WHEN YOU TURN THE KEY, LISTEN TO HEAR IF YOU CAN HEAR THE FUEL PUMP COME ON...IF NOT, GUESS WHAT? HOPEFULLY NOT!... BUT,YOU MAY NEED TO REPLACE THE FUEL PUMP, IF YOU CAN'T HEAR IT WHEN YOU TURN THE KEY, AFTER YOU'VE RESET THE BATTERY!

HOPE THIS HELPS!