Security Lamp/Indicator: Description and Operation

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 SKIS indicator lamp is located near the upper edge of the instrument cluster overlay, in the upper left quadrant of the cluster. The SKIS indicator consists of a stenciled cutout of a graphical representation or icon of a key that is circled and crossed-out in the opaque layer of the instrument cluster overlay. The dark outer layer of the cluster overlay prevents the icon from being clearly visible when the lamp is not illuminated. However, an amber lens behind the cutout in the opaque layer of the cluster overlay causes the icon to appear in amber through the translucent outer layer of the overlay when it is illuminated from behind by a replaceable incandescent bulb and bulb holder unit located on the instrument cluster electronic circuit board. The SKIS indicator lamp is serviced as a unit with the instrument cluster.

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 the instrument cluster circuit board based upon electronic messages received by the cluster from the Sentry Key Immobilizer Module (SKIM) over the Chrysler Collision Detection (CCD) data bus. The SKIS indicator lamp bulb receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (st-run) circuit whenever the ignition switch is in the ON or Start positions; therefore, the lamp will always be OFF when the ignition switch is in any position except ON or Start. The lamp bulb only illuminates when it is switched to ground by the instrument cluster circuitry. 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.
- SKIM Lamp-ON Message - Each time the cluster receives a 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 SKIM message. For more information on the SKIS and the SKIS lamp control parameters, (Refer to VEHICLE THEFT SECURITY - 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 and OFF in a prescribed sequence to confirm the functionality of the lamp and the cluster 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. The SKIM then sends the proper SKIS lamp-ON or lamp-OFF messages to the instrument cluster. If the SKIS indicator lamp fails to light during the bulb test, replace the bulb with a known good unit. 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 CCD 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.