Sentry Key Immobilizer System (Skis)

The SKIS is an immobilizer system designed to prevent unauthorized vehicle operation. The system consists of a Sentry Key Immobilizer Module (SKIM) and ignition key(s) called Sentry Key(s) which are equipped with a transponder chip. The SKIM communicates over the Programmable Communication Interface multiplex system (PCI) bus network to the instrument cluster, Powertrain Control Module (PCM), and the DRBIII® scan tool.

The SKIM sends messages to the instrument cluster over the PCI bus to control the VTSS indicator lamp. The SKIM sends a message to the instrument cluster to turn the lamp on for about three seconds when the ignition is turned to the Run/Start position as a bulb test. If the indicator lamp comes on and stays on after the bulb test, it indicates that the SKIM has detected a system malfunction and/or that the SKIS has become inoperative. If an invalid key is detected in the ignition key cylinder with the ignition switch in the Run/Start position the SKIM will flash the VTSS indicator lamp on and off.

For additional information on the SKIS, refer to TRANSMISSION DIAGNOSTIC PROCEDURES .