The PASS-Key® III system is a function of the PASS-Key®
III Theft Deterrent (VTD) module. When a ignition key is inserted into the
ignition lock cylinder, the PASS-Key® III reader exciter 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
PASS-Key® III reader exciter. The PASS-Key® III reader exciter
sends this value to the VTD 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 VTD activates the
vehicle starter relays and the PCM enables fuel delivery to the engine by
activating the fuel injectors. |
| | Important: The VTD module and PCM operate in conjunction with each other to determine
fuel enable. A password is exchanged between the VTD module and PCM when the
VTD 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. |
| - | If the password does not match the PCM disables fuel delivery
and sets a DTC. |
| • | If the value does not match the stored value, the VTD module does
not activate the vehicle starter relays and the PCM disables fuel delivery
to the engine by disabling the fuel injectors. |
SECURITY Indicator Operation
The VTD module commands the instrument cluster to illuminate the SECURITY
indicator only when the ignition key is in the ON position. Under the following
conditions the VTD module commands the SECURITY indicator to illuminate.
Bulb Stays Illuminated and Engine Starts
If the indicator stays illuminated after the engine starts this indicates
that one of the following conditions has occurred:
| • | After the engine is running, the VTD module measures an invalid
transponder value for 30 consecutive seconds. The VTD module may allow the
engine to restart during this condition. |
| • | If the VTD module detected a problem in the PASS-Key® III
while the engine was last running the indicator illuminates for the first
thirty seconds of each ignition cycle, until the problem is corrected. |
Bulb Stays Illuminated and Engine Does Not Start
The VTD module measures an invalid transponder value when the ignition
key is turned to the ON position.
Bulb Flashes and Engine Does Not Start
If the indicator flashes and the engine does not start, the VTD module
has detected a problem with the PASS-Key® III system. During this mode
of operation the VTD module does not start the system disable interval.
