Back when I was in high school, mom had a 2001 Explorer with the keypad on the door. Greatest invention ever.I found this on a Ford dealer's web site:
Your Keyless Entry Key Pad can do more than just unlock the driver side door.
Once you enter in your key code press button 3/4 to unlock all doors.
If you press button 5/6 after your key code is entered it will open your lift gate if you vehicle is equipped with one.
Instead of fumbling around with your keys to find the lock button just press button7/8 and 9/0 at the same time to lock all your doors.