Antitheft - Passive

The PATS uses a specially encoded ignition key, this key is not compatible with previous vehicles or any current model year vehicles. Each specially encoded ignition key contains a permanently installed electronic device called a transponder. Each transponder contains a unique encrypted identification code out of over 18 billion, billion combinations.

Each encoded ignition key must be programmed into the vehicle's Powertrain Control Module (PCM) before it can be used to start the engine. There are special diagnostic repair procedures outlined that must be carried out if a new encoded ignition key is necessary.

This system contains a new feature named Unlimited Key Mode. This feature allows a customer to program more than eight keys to their vehicle if they request it. Each vehicle in Unlimited Key Mode is set up with a special Unlimited Transponder Security Key. This allows all the customer vehicles to share the same keys, but no other keys from outside can be used to operate the vehicles. For an individual customer, any randomly selected Security Key is acceptable. Refer to Key Programming - Unlimited Key Mode. Unlimited Key Mode

The PATS transceiver module communicates with the encoded ignition key. The module is located behind the steering wheel column shroud and contains an antenna connected to a small electronics module. During each vehicle start sequence, the transceiver module reads the encoded ignition key identification code and sends data to the PCM.

The control functions are contained in the PCM. This module carries out all of the PATS functions, such as receiving the identification code from the encoded ignition key and controlling the engine enable. The PCM initiates the key interrogation sequence when the vehicle ignition switch is turned to RUN or START.

All elements of the PATS must be functional before the engine is allowed to start. If any of the components are not working correctly, the vehicle will not start.

The PATS uses a visual theft indicator. The indicator will prove out for three seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS problem, this indicator will either flash rapidly or glow steadily when the ignition switch is turned to RUN or START. The PATS system also flashes the theft indicator every two seconds at ignition OFF to act as a visual deterrent.

The PATS will be activated and will disable the vehicle from starting if there is a:
^ improper encoded ignition key (example - Taurus/Sable key).
^ damaged encoded ignition key.
^ unprogrammed key.
^ non-encoded key (key has no electronics).
^ damaged wiring.
^ damaged transceiver.
^ damaged PCM.