Vehicle Theft Deterrent (VTD) Operation

The theft deterrent system is a function of the theft deterrent module. When a ignition key is inserted into the ignition lock cylinder, the theft deterrent module uses wire coils surrounding the ignition lock cylinder to energizes a transponder pellet located within the plastic portion of the ignition key. The transponder when energized transmits a unique value by radio frequency back to the theft deterrent module. The theft deterrent module which then validates this value against a value stored in memory and performs one of the following functions:
^ If the value does match the stored value the theft deterrent module sends the correct password via a class 2 message to the PCM, and the PCM enables fuel delivery to the engine by activating the fuel injectors and activates the starter relay.

IMPORTANT: The theft deterrent module and PCM operate in conjunction with each other to determine fuel enable. A password is exchanged between the theft deterrent module and PCM when the theft deterrent module detects a valid key value over the class 2 serial data line. When the PCM receives a password the PCM validates the password against a password stored in memory and performs one of the following functions:
- If the password matches the PCM enables fuel delivery, and activates the starter relay.
- If the password does not match the PCM disables fuel delivery, and does not activate the starter relay and sets a DTC.

^ If the value does not match the stored value, the PCM disables fuel delivery to the engine by disabling the fuel injectors, and does not activate the vehicle starter relay.