VTSS/Skis Indicator: Operation

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

The Vehicle Theft Security System (VTSS) / Sentry Key Immobilizer System (SKIS) indicator gives an indication to the vehicle operator of the status of the VTSS/SKIS. This lamp is controlled the instrument cluster circuit board based upon messages received by the cluster from the Sentry Key Remote Entry Module (SKREEM) over the Controller Area Network (CAN) data bus. The VTSS/SKIS indicator lamp receives battery current on the instrument cluster circuit board through the fused ignition switch output (st-run) circuit whenever the ignition switch is in the On or Start positions. The lamp only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn on the SKIS indicator lamp for the following reasons:

Bulb Test - Each time the ignition switch is turned to the On position, the SKREEM tells the cluster to illuminate the lamp for about three seconds.
SKIS Lamp-On Message - Each time the cluster receives a SKIS lamp-on message from the SKREEM, the lamp will be illuminated. The lamp can be flashed on and off, or illuminated solid, as dictated by the message from the SKREEM. For more information on the SKIS and the SKIS lamp control parameters, (Refer to ELECTRICAL/VEHICLE THEFT SECURITY - OPERATION - SENTRY KEY IMMOBILIZER SYSTEM) . The lamp remains illuminated until the cluster receives a lamp-off message from the SKREEM or until the ignition switch is turned to the Off position, whichever occurs first.
Actuator Test - Each time the cluster is put through the actuator test with the scan tool, the lamp will be turned on for the duration of the test to confirm the functionality of the lamp and the cluster.

The SKREEM performs a self-test each time the ignition switch is turned to the On position to decide whether the system is in good operating condition. The SKREEM then sends a message to the instrument cluster. If the SKIS indicator fails to light during the bulb test, refer to the appropriate diagnostic information. If the instrument cluster turns on the VTSS/SKIS indicator after the bulb test, either solid or flashing, it indicates that a SKIS malfunction has occurred or that the VTSS/SKIS is inoperative. For proper diagnosis of the SKIS, the CAN data bus, or the message inputs to the instrument cluster that control the VTSS/SKIS indicator lamp, a scan tool and the appropriate diagnostic information are required.