Security Lamp/Indicator: Description and Operation

VTSS/SKIS INDICATOR LAMP
The Sentry Key Immobilizer System (SKIS) uses an indicator light to convey information on the status of the system to the customer. This light is shared with the Vehicle Theft Security System (VTSS). The light is located in the Instrument Cluster. The indicator light is controlled by the Body Control Module (BCM) based upon messages it receives from the Sentry Key Immobilizer Module (SKIM) on the PCI bus.

When the ignition is turned ON, the BCM performs a four second bulb check, regardless of SKIM messages. After the bulb check, the lamp is controlled according to SKIM messages. Then, the SKIM sends messages to the BCM to operate the light based upon the results of the SKIS self tests. The light may be actuated in two possible ways, flashing or ON solid. If the light comes ON and stays on solid after a power-up test, this indicates that the SKIM has detected a system malfunction. If the SKIM detects an invalid key when the ignition switch is moved to the ON position, it sends a message on the PCI bus to the BCM, to flash the light. The SKIM can also send a message to flash the light and generate a single audible chime at the same time. These two events occurring simultaneously indicate that the SKIS has been placed into the "Customer Learn" mode. Refer to Electrical, Vehicle Theft Security Transponder Key, Standard Procedure - Transponder Programming for more information on the "Customer Learn" mode. If the light comes ON and stays ON after the power-up test, diagnosis of the SKIS should be performed using a DRB III scan tool and the appropriate Body Diagnostic Procedures manual. The light is not a serviceable component.

Solid indicator that there is a system failure.
- Loss of PCM communication. Failed antenna circuit.