SENTRY KEY IMMOBILIZER SYSTEM
TABLE OF CONTENTS
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DESCRIPTION AND OPERATION
SENTRY KEY IMMOBILIZER SYSTEM . . . . . . . . . . 6
SENTRY KEY IMMOBILIZER MODULE. . . . . . . . . . 7
SENTRY KEY IMMOBILIZER SYSTEM
INDICATOR LAMP. . . . . . . . . . . . . . . . . . . . . . . . 8
SENTRY KEY IMMOBILIZER TRANSPONDER . . . . 8
DIAGNOSIS AND TESTING
SENTRY KEY IMMOBILIZER SYSTEM . . . . . . . . . . 9
SERVICE PROCEDURES
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER PROGRAMMING . . . . . . . . . . . 9
REMOVAL AND INSTALLATION
SENTRY KEY IMMOBILIZER MODULE. . . . . . . . . 10
DESCRIPTION AND OPERATION
SENTRY KEY IMMOBILIZER SYSTEM
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) is
standard factory-installed equipment for this model.
The SKIS is designed to provide passive protection
against unauthorized vehicle use by preventing the
engine from operating without a valid key. Following
are some general descriptions of the features and
components of the SKIS.
The SKIS includes the following components:
• Sentry Key Immobilizer Module (SKIM)
• Sentry Key Immobilizer System indicator lamp
• Sentry Key transponder
Certain functions and features of the SKIS rely
upon resources shared with other electronic modules
in the vehicle over the Programmable Communica-
tions Interface (PCI) data bus network. The PCI data
bus network allows the sharing of sensor informa-
tion. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased
reliability,
enhanced
diagnostics,
and
allows the addition of many new feature capabilities.
For diagnosis of these electronic modules or of the
PCI data bus network, the use of a DRBIII
t scan tool
and the proper Diagnostic Procedures manual are
recommended.
The other electronic modules that may affect SKIS
operation are as follows:
• Body Control Module (BCM) - Refer to Body
Control Module in the Description and Operation
section of Group 8E - Instrument Panel Systems for
more information.
•
Electro-Mechanical
Instrument
Cluster
(EMIC) - Refer to Instrument Cluster in the
Description and Operation section of Group 8E -
Instrument Panel Systems for more information.
• Powertrain Control Module (PCM) - Refer
to Powertrain Control Module in the Description
and Operation section of Group 14 - Fuel System for
more information.
Refer to Fuel/Ignition System in the Contents of
Group 8W - Wiring Diagrams for complete circuit
diagrams. Following are general descriptions of the
features and major components of the SKIS.
OPERATION
The SKIS uses a Radio Frequency (RF) transceiver
and electronically coded Sentry Key transponders to
verify that a valid key is inserted in the ignition
switch lock cylinder. If the SKIS recognizes the key
as valid, it sends messages to the PCM that will
allow the engine to run. If the SKIS does not recog-
nize a valid key, the engine will not run. While the
engine starting system will operate and the engine
may initially start and run up to about 800 revolu-
tions-per-minute on residual fuel pressure, the vehi-
cle cannot be driven without a valid Sentry Key
transponder.
The SKIS includes two valid Sentry Key transpon-
ders from the factory. If the customer wishes, addi-
tional non-coded blank Sentry Keys are available.
These blank keys can be cut to match a valid ignition
key, but the engine will not run unless the key tran-
sponder is also programmed to the vehicle. The SKIS
will recognize no more than eight valid Sentry Key
transponders at any one time.
The SKIS performs a self-test each time the igni-
tion switch is turned to the On position, and will
store Diagnostic Trouble Codes (DTCs) if a system
malfunction is detected. The SKIS can be diagnosed,
and any stored DTC can be retrieved using a
DRBIII
t scan tool as described in the proper Diag-
nostic Procedures manual.
8Q - 6
VEHICLE THEFT/SECURITY SYSTEMS
WJ