Passive Anti-Theft System (PATS) Warning Indicator
WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
The PATS transceiver module is hardwired to the instrument cluster. When the key is placed into the ignition lock cylinder, and turned to the ON or START position, the PATS transceiver reads the electronic code stored in the ignition key, and transmits this code to the instrument cluster. If the electronic code is correct, the instrument cluster transmits the key status over the communication network to the PCM to enable the starter relay, the fuel pump, and the fuel injectors. If a theft is detected, the instrument cluster flashes the PATS warning indicator.