2001 Mercedes-Benz CLK-Class master key

                The Problem

1- The master key does not open the doors or the trunk.
2- when I put the key in the starter (ignition) it does not turn, and I can not start the engine and it makes a sign in the front (remove the key)

The battery in the master key has gone dead, the security system cannot identify the key as correct so won’t allow you to start the car. Replace the battery.