Section 15 (Immobilizer Systems): Description
Immobilizer vehicle protection system, or Passive Anti-Theft System (PATS), is designed to prevent driveaway thefts. The system is passive in that it does not require any activity from the user. Radio frequency identification technology is used to verify proper key is being used to attempt to start the vehicle.
Immobilizer system consist of Passive Anti-Theft System (PATS) module, a permanently encoded transponder equipped ignition key, PATS transceiver module (part of ignition lock cylinder), Powertrain Control Module (PCM), THEFT indicator light, module communications network, Data Link Connector (DLC), and related wiring and fuses. See Fig 1.
During each starting sequence, the transceiver module reads the encoded ignition key identification code and sends the data to the PATS module. If the key's identification code is programmed into anti-theft system, vehicle is allowed to start. If key's identification code is incorrect or missing, vehicle is prevented from starting.