My Key Will Not Turn in an E320


1. Wiggle the steering wheel while turning the key. If there is pressure on the steering wheel that holds it on the lock pin, the key will not turn. A locked steering wheel is not the source of the problem if the steering wheel turns but the key still does not turn.
2. Start the car with a spare key. If the spare key works but the main key does not, you obviously have a bad main key. A replacement key for the E320 costs around $200 as of January 2011. You will need a valid registration and title to complete the purchase.
3. Place the key in the ignition and listen for a clicking noise. If both the spare key and the main key fail to turn, and you hear a clicking noise when you insert the key into the ignition, you most likely have a bad ignition switch. Visit a Mercedes-Benz dealership or a repair shop to confirm this diagnosis. A new ignition switch for the E320 will run you about $1,000 as of January 2011.