hi,depends on the year of your car,you should have a master key if not, if you have two programmed keys turn ignition on wait till pats light comes on and goes off do the same with other programmed key,when this is done put un programmed key in ignition turn on and start car,Be as quick as you can when you perfom each key change.if this doesent work you may need to take to a ford dealer?
propshaft
April 2008