All late model Mercedes-Benz vehicles are equipped with key fobs on each key that allow drivers to lock and unlock your vehicle without needing to insert your key into the door lock. This is a great feature to have if you need to get into your car when your hands are full, or it's raining or you're getting into your car in a dark car park. If you acquire a new key for your Mercedes, you will need to reset the key prior to using it or it will not work with your Mercedes-Benz vehicle.
Put your key in the ignition of your Mercedes-Benz and push and hold the lock button while the key is in the ignition. Do not turn on your vehicle during this process and do not let go of the lock button.
Remove your car key from the ignition while you are still holding the lock button. Click the unlock button on the fob five times, still holding down the lock button.
Remove your finger from the lock button and your key should be reset. Test your key fob to ensure that it works.
If you have trouble resetting your key fob, call your Mercedes-Benz dealership for assistance. This information is located in your owner's manual, which you should refer to prior to attempting to reset your key fob.