ford keys losing program

Recently I installed a matrix 3.5 rsx in a 1998 expedition.Everything works fine except all of the keys lose there program except the key in the 556u.The only way to start the car is to remote start it,put the key in and hit the brake and it runs as usual.Have tried to reprogram the keys but it still does the same thing.

have you try hookin up the key sense wire to the ford's keysense? i would try not to let the system see both key at the same time... just a thot.Houston,TX

"The two most common elements in the universe are H+ and stupidity" (Ellison).

Yes.... the loop is "on" on the 556U all the time. They do this so that when you are hard wiring into say a VW, Audi, BMW, Hyundai factory antenna, the factory system is still intact. Use keysense.... I believe it is positive, BLACK/ pink on plug on right side of column. This will open the loop circuit of the 556U when the key is inserted, and the vehicle won't see 2 keys at any given time. Bit of a PITA, yes, but, no biggie. Gus Wherever I go, that is where I end up......

No the 556u should not be on all the time if it was that would be bypassing the anti theft system all the time, so you would be able to start it with any key. If the 556u is working right it will only transmit the signal while remote starting.The keysense wire is for when you place the key in the ign. it will turn off the 556u because on some cars they can not see 2 key codes. On most fords once its running it dooes not matter if it sees another key or not.