Beginning in 1999, Ford and Mercury vans offered remote-controlled power sliding door and liftgate option packages for the first time. Two factory keyless entry remote keyfobs were used on suitably equipped Windstar, Freestar, Freestyle and Monterey vans. It is important to note that these two keyfobs are not interchangeable.
The Ford 5-button remote with lock, unlock, panic and dual power sliding door buttons has FCC ID CWTWB1U511 on the back. See remote at this link.
The Ford 6-button remote adds a power liftgate button. It has FCC ID CWTWB1U551 on the back. See remote at this link.
The factory keyless entry systems in vans that use these remotes are all user programmable, so one can buy a new replacement remote and use it without having to go to a dealership for programming. Remotes Unlimited provides easy-to-follow instructions and free phone technical support for customers who buy a remote.