I have a Mercedes Benz S500 year 2000 I cannot open the doors by the electronic key and when I open the driver door by mechanical key or the trunk, the key doesn't open at all. The car was parked at the port since 10th June but a week later I opened the car without any problem but today was not able to pick the car cause I couldn't open the doors

Open the hood locate the fuse box on the passengers side near fire wall back feed 12 volts into to large fuse that is loose all by its self conected by 2 wires .I think its a 40 amp . By back feeding 12 volts into the system you can pop the trunk lid with the door switch.

Hi, Get a can of spray lube and spray in the lock, the lock maybe gummed up.
When you get it open lube up the mechanism. Good luck.

possibly flat battery in your car open the boot by key blade and jump the battery when you jup the battery be careful don't mix up the connection

my truck on my s500 2000 model will not open at all, not will the key and not on the door the key doing everything it suppose to do with the windows and the sunroof, bnut them truck will not pop up could it be a fuse or is the the lock is stuck

Isn't there botton somewere on the door or left lower conner of dashboard to open trank remotely?

LOOK ON THE DASH AND BY THE DRIVERS SEAT OR IN THE GLOVE BOX FOR A BUTTON TO OPEN THE TRUNK YOU SHOULD FIND ONE

The door lock mechanism is located on the driver's side luggage compartment on left pannel

Your trunk lock actuator is probably in valet mode. Take the mechanical key out of your smart key(should have a release button on the bottom of the key which will allow you to slide the hidden mechanical key out of the plastic housing) insert it into your trunk lock actuator and turn to change your function of trunk actuator. In the valet mode the trunk does not respond to your central locking or release button commands. Your owner's manual will tell you about these features. I hope I have been helpful

Trunk can be lock separate from the doors valet try unlocking the trunk with the key lock it with the door.Read the owner manual it will tell you about valet parking.

Have you checked for blown fuse in panel.