Replace the battery on your remote key. If you get the dealer to do it for you it is notoriously expensive.
Did you try unlocking the passenger side with the key?
cant open the case to get to the dead batteries. How do I open the case
There are a couple of reasons: The battery is dead - replace battery. Some auto parts stores have a remote tester that will show if the remote is transmitting. The contacts on the fob have a buildup of carbon - open remote and use a pencil eraser to clean the contacts. The unit has lost its sync with the car. Go to a good locksmith or the dealer to have it reprogrammed. Or, the remote is broken.
The battery in the remote may be dead, or the remote or security system may have a fault of some sort.
You can if the key has a door lock/unlock button. I lock mine all the time with the remote. If you have the button on the key and it is not working then maybe the battery in the remote is dead? Open it up and replace the battery.
To unlock a 2002 Mercedes SL 500 with a dead battery, you can use the mechanical key hidden within the key fob. First, remove the key by pressing the release button on the fob. Then, locate the small keyhole on the driver's side door handle and insert the mechanical key to unlock the door manually. Once inside, you can access the battery to jump-start or replace it.
Is the remote's battery dead?
If the key will not work in the door or the liftgate, you will need to call a locksmith or break a window.
Part if the door handle pops off. Look under the dirt Handel and you should see it. Then use the key from the remote.
this is probarly because your remotes battery is dead or the key is broken. Some new modles are voice activated so you hold the remote to your mouth and say open
should have back up capacitors, allow one or two unlock. if its dead beyond this you may need to contact dealer. The computer key for the s class has an actual key incorporated in it allowing the car to be unlocked manually.
remove plastic cover next to driver door handle using the key in remote fob and then insert key into lock.
There should be a metal key hidden in the plastic key. It slides out of the side. i think this will unlock the door if the car or key battery are dead.