SecuriLock, also known as Passive Anti-Theft System (PATS), is Ford Motor Company's immobilizer technology. In 1996 it started showing up on select models of Ford, Lincoln, and Mercury vehicles. The keys for these vehicles have a minute radio frequency transponder embedded in the plastic Head.
When the vehicle is started, the on-board computer sends out a RF signal that is picked up by the transponder in the key. The transponder then returns a unique RF signal to the vehicle's computer, giving it confirmation to start and continue to run. This all happens in less than one second, with the intention of being completely transparent to the vehicle's operator.
Replacement of keys to vehicles equipped with engine immobilizers is different than that for a vehicle with conventional keys. Since the key is assembled with electronic components, one cannot be purchased and made at a retail store. The vehicle must be taken to a dealership so programming can be done.
For the 1999 model year, all Ford Motor Company vehicles equipped with the Passive Anti-Theft System used 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.
With PATS I, programming of a new key could be done with just one working key. Information on how this was completed was provided in the vehicle's owner's manual.
With PATS II, two working keys were required for reprogramming. This helped ensure that only the owner of the vehicle could make duplicate keys.
PATS I equipped vehicles include the following.
PATS II equipped vehicles include the following: