SecuriLock, also known as Passive Anti-Theft System (PATS), is an immobilizer technology that Ford began using select Ford as well as Lincoln, and Mercury models. Each key have a radio frequency transponder embedded in the plastic head with a unique electronic identification code.
When the a key is inserted and turned to start the vehicle, the on-board computer sends out an RF signal which is picked up by the transponder in the key. In less than one second, the transponder then returns a unique RF signal to the vehicle's computer, giving confirmation to start and continue to run. If the on-board computer does not receive the correct identification code, certain components, such as the fuel pump and on some the starter, will remain disabled.
Replacement keys, which can be purchased through the dealer or a 3rd party, must be compatible with the vehicle. Before the key can be used to start the vehicle it must be programmed, done by inserting the original key(s) as well as the new key into the ignition.
With PATS I, programming of a new key can be done with just one working key. With PATS II, two working keys are required for reprogramming. This helped ensure that only the owner of the vehicle can make duplicate keys. If a second working key is not available programming will need to be performed by the dealer.
For the 1999 model year, all Ford Motor Company vehicles equipped with the Passive Anti-Theft System use the PATS II system. The PATS II system was introduced on roughly half of the PATS equipped vehicles for the 1998 model year. The other half of the PATS equipped vehicles for the 1998 model year were equipped with the PATS I system. Many 2000 and later Ford vehicles use the E-PATS system, which uses an encrypted transponder in the key.
PATS I equipped vehicles include the following.
PATS II equipped vehicles include the following: