My fob still turns on the car and unlocks when using the door sensor but the unlock, lock, trunk, and alarm are no longer working after replacing battery on your key fob. (car still unlocks by door sensor and still turns on) here is how to fix it with out going to the dealer. you have to sync the remote to you car make sure you hold your key with the the logo up and you are going to hold the lock button while pressing the start button but make sure your foot is not on the brake do not turn your car on completely all your going to do is press the push start NO BRAKES.