Security Lamp/Indicator: Description and Operation
SKIS INDICATORA Sentry Key Immobilizer System (SKIS) indicator is standard equipment on all instrument clusters, but is only operational on vehicles equipped with the optional SKIS. The SKIS indicator is located in the upper right corner of the instrument cluster, to the right of the speedometer. The SKIS indicator consists of a graphical representation or icon of a circled and crossed-out key imprinted on an amber lens. The lens is located behind a cutout in the opaque layer of the instrument cluster overlay. The dark outer layer of the overlay prevents the indicator from being clearly visible when it is not illuminated. The icon appears silhouetted against an amber field through the translucent outer layer of the overlay when it is illuminated from behind by an incandescent bulb and bulb holder unit located on the instrument cluster electronic circuit board. The SKIS indicator lens is serviced as a unit with the instrument cluster lens, hood and mask unit.
The Sentry Key Immobilizer System (SKIS) indicator gives an indication to the vehicle operator of the status of the SKIS. This indicator is controlled by a transistor on the instrument cluster electronic circuit board based upon cluster programming and electronic messages received by the cluster from the Sentry Key Immobilizer Module (SKIM) over the Programmable Communications Interface (PCI) data bus. The SKIS indicator bulb is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (RUN/START) circuit. Therefore, the indicator will always be OFF when the ignition switch is in any position except ON or Start. The bulb only illuminates when it is switched to ground by the instrument cluster transistor.
The instrument cluster will turn ON the SKIS indicator for the following reasons:
- Bulb Test - Each time the ignition switch is turned to the ON position, the SKIM tells the cluster to illuminate the SKIS indicator for about three seconds as a bulb test.
- SKIS Indicator lamp-ON Message - Each time the cluster receives a SKIS indicator lamp-ON message from the SKIM, the SKIS indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the SKIM message. For more information on the SKIS and the SKIS indicator control parameters, refer to Vehicle Theft Security System Description and Operation. The indicator remains illuminated until the cluster receives a SKIS indicator lamp-OFF message from the SKIM, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Communication Error - If the cluster receives no SKIS indicator lamp-ON or lamp-OFF messages from the SKIM for twenty consecutive seconds, the SKIS indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid SKIS indicator lamp-ON or lamp-OFF message is received from the SKIM.
- Actuator Test - Each time the cluster is put through the actuator test, the SKIS indicator will be turned ON for the duration of the test to confirm the functionality of the bulb and the cluster control circuitry.
The SKIM 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 and whether a valid key is present in the ignition lock cylinder. The SKIM then sends the proper SKIS indicator lamp-ON or lamp-OFF messages to the instrument cluster. If the SKIS indicator fails to light during the bulb test, replace the bulb with a known good unit. For further diagnosis of the SKIS indicator or the instrument cluster circuitry that controls the indicator, refer to Instrument Cluster Diagnosis and Testing. If the instrument cluster flashes the SKIS indicator upon ignition ON, or turns ON the SKIS indicator solid after the bulb test, it indicates that a SKIS malfunction has occurred or that the SKIS is inoperative. For proper diagnosis of the SKIS, the PCI data bus, or the electronic message inputs to the instrument cluster that control the SKIS indicator, a DRB III scan tool is required. Refer to the appropriate diagnostic information.
SKIS INDICATOR LAMP
A Sentry Key Immobilizer System (SKIS) indicator lamp is standard equipment on all instrument clusters, but is only functional on vehicles equipped with the optional SKIS. The amber SKIS indicator lamp is located to the right of the oil pressure gauge.
The Sentry Key Immobilizer System (SKIS) indicator lamp gives an indication to the vehicle operator of the status of the SKIS. This lamp is controlled by a transistor on the instrument cluster circuit board based upon messages received by the cluster from the Sentry Key Immobilizer Module (SKIM) over the Programmable Communications Interface (PCI) data bus. The SKIS indicator lamp bulb 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 bulb 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 SKIM 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 SKIM, the lamp will be illuminated. The lamp can be flashed ON and OFF, or illuminated solid, as dictated by the message from the SKIM. For more information on the SKIS and the SKIS lamp control parameters, refer to Sentry Key Immobilizer System Description and Operation. The lamp remains illuminated until the cluster receives a lamp-off message from the SKIM 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, the lamp will be turned ON for the duration of the test to confirm the functionality of the lamp and the cluster.
The SKIM 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 SKIM then sends a message to the instrument cluster. If the SKIS indicator lamp fails to light during the bulb test, replace the bulb. For further diagnosis of the SKIS indicator lamp or the instrument cluster circuitry that controls the lamp, refer to Instrument Cluster Diagnosis and Testing. If the instrument cluster turns ON the SKIS indicator lamp after the bulb test, either solid or flashing, it indicates that a SKIS malfunction has occurred or that the SKIS is inoperative. For proper diagnosis of the SKIS, the PCI data bus, or the message inputs to the instrument cluster that control the SKIS indicator lamp, a DRB III scan tool and the appropriate diagnostic information are required.
VTSS INDICATOR
The Vehicle Theft Security System (VTSS) indicator consists of a red Light-Emitting Diode that is mounted and integral to the automatic headlamp light sensor photo diode unit, which is located on the top of the instrument panel. The remainder of the housing including the mount and the electrical connection are concealed beneath the instrument panel top cover.
The VTSS indicator cannot be adjusted or repaired the entire automatic headlamp light sensor/VTSS indicator must be replaced.
The Vehicle Theft Security System (VTSS) indicator gives a visible indication of the VTSS arming status. One side of Light Emitting Diode (LED) in the VTSS indicator is connected to unswitched battery current through a fused B(+) circuit and a fuse in the Junction Block (JB). The other side of the LED is hard wired to the Body Control Module (BCM), which controls the operation of the VTSS indicator by pulling this side of the LED circuit to ground. When the VTSS arming is in progress, the BCM will flash the LED rapidly ON and OFF for about 15 seconds. When the VTSS has been successfully armed, the BCM will flash the LED ON and OFF continually at a much slower rate until the VTSS has been disarmed. The VTSS indicator can be diagnosed using conventional diagnostic tools and methods.