Passive Anti-Theft System (PATS) Transceiver
WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.
The PATS transceiver is located in the steering column and communicates with the encoded ignition key. During each vehicle start sequence, the PATS transceiver reads the encoded ignition key identification code and sends data to the IPC. The IPC validates the code, and if it is correct, sends a message to the PCM to ground the starter relay solenoid coil and to allow the fuel injectors to operate.