The Ford Focus offers keyless entry using a small handheld remote. This "key" (more accurately called the "key fob" or "transmitter") comes preprogrammed from the dealership when you buy the car, but every now and then you might need to reset it. The reprogramming procedure on the Ford Focus is relatively easy once you know exactly what steps to take. If you can turn a key and count to eight, you're already halfway there.
Unlock the doors of your Ford Focus.
Insert your metal car key into the ignition and turn it clockwise to the "On" position.
Cycle the key between "Off" and "On" eight times in rapid succession, ending at "On."
Press any button on your handheld remote. You must do this within 20 seconds or you'll have to do the entire procedure over again.
Turn the key in the ignition back to "Off."
Your remote has a range of about 33 feet, according to Ford. If your remote doesn't work, check the battery; it may require replacement.