Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, my name is***** sounds like either a fault with the key itself or a fault with the electronic ignition switch or the electronic steering lock. If the accessory items do not work with the key on the problem is usually a faulty electronic steering lock. You can try using your spare key if you have one but aside from that the car will need to go to a Mercedes specialist for a diagnosis with the Mercedes tester.
Let me know if you have any questions.