General

Insert the ignition key into the ignition cylinder. The wire coils surrounding the ignition cylinder energizes a transponder pellet located within the plastic portion of the ignition key. The energized transponder transmits a unique value by radio frequency back to the coils which are part of the theft deterrent module. When the theft deterrent module detects the ignition voltage (the ignition switch is in RUN or START) the module measures the transponder pellet value being received by the coils. The theft deterrent module validates this value and performs the following functions:
^ If the value is valid, the theft deterrent module performs the following (system enable) functions:
- Sends a class 2 system enable message (a unique password) to the PCM
- The PCM enables the fuel system
- The PCM provides a ground for the starter relay
- This function enables the engine to start
^ If the value is invalid, the theft deterrent module performs the following (system disable) functions for approximately 3 minutes:
- Sends a class 2 system disable message (a unique password) to the PCM
- The PCM does not enable the fuel system.
- The PCM does not provide a ground for the starter enable relay.
- This function does not enable the engine to start for approximately 3 minutes.

This password is unique for each theft deterrent module, thus preventing a thief from swapping one of the following in order to start the vehicle:
^ The theft deterrent module
^ The PCM

If the PCM receives an invalid password indicating a swapped theft deterrent module or PCM, the following systems are not enabled:
^ The fuel system
^ The starter system

If you turn the ignition switch to RUN at anytime during the system disable interval, the theft deterrent module disregards the transponder value until the 3 minute system disable interval is complete (even if an ignition key using a valid transponder is used). When the system disable interval expires, the theft deterrent module measures the ignition key transponder value when the ignition switch is turned to the RUN position.
If the theft deterrent module is unable to measure the ignition key transponder value (due to a damaged or wrong key), the theft deterrent module performs the system disable functions. The module does not activate the 3 minute system disable interval. An ignition key using a valid transponder value may be used in order to start the vehicle.