OPERATION

The security indicator gives an indication to the vehicle operator when the Vehicle Theft Security System (VTSS) is arming or is armed. On vehicles equipped with the Sentry Key Immobilizer System (SKIS), the security indicator also gives an indication to the vehicle operator of the status of the SKIS. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming, and electronic security indicator request messages received by the cluster from the Totally Integrated Power Module (TIPM) or the Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM) over the Controller Area Network (CAN) data bus.

The security indicator Light Emitting Diode (LED) is completely controlled by the instrument cluster logic circuit, and that logic will allow this indicator to operate whenever the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. Depending upon the programmed condition, the indicator can be illuminated solid, flashed at a slow rate (0.5 Hertz, 12.5 percent duty cycle), or flashed at a fast rate (1 Hertz, 50 percent duty cycle). The instrument cluster will turn ON the security indicator for the following reasons:

• Bulb Test - Each time the ignition switch is turned to the ON position the security indicator illuminates for about two seconds as a bulb test. The entire bulb test is a function of the SKREEM.
• Security Indicator Lamp-On Message - During the 16 second VTSS arming function, the TIPM will request the cluster flash the security indicator ON and OFF repeatedly at a steady, fast rate to indicate that the VTSS is in the process of arming. Following successful VTSS arming, the TIPM will request the cluster flash the security indicator ON and OFF continuously at a slower rate to indicate that the VTSS is armed. The security indicator continues flashing at the slower rate until the VTSS is disarmed or triggered. If the VTSS has alarmed and rearmed, the TIPM will request the cluster flash the security indicator at a steady, slow rate for about 30 seconds after the VTSS is disarmed.
• SKIS Indicator Lamp-On Message - Each time the cluster receives an electronic SKIS indicator lamp-ON message from the SKREEM, the security indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the SKREEM message. The indicator remains illuminated solid or continues to flash 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. For more information on the SKIS and the security indicator control parameters, (Refer to 8 - ELECTRICAL/VEHICLE THEFT SECURITY/SENTRY KEY IMMOBILIZER SYSTEM - OPERATION).
• Communication Error - If the cluster receives no lamp-ON or lamp-OFF messages from the TIPM or the SKREEM for 10 consecutive message cycles, the security indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid lamp-ON or lamp-OFF message is received from the SKREEM.
• Actuator Test - Each time the instrument cluster is put through the actuator test, the security indicator will be turned ON, then OFF again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The TIPM sends electronic security indicator request messages to control the security indicator whenever the ignition switch is in the OFF position and the VTSS is arming, armed, or alarming. Whenever the ignition switch is in the ON or START positions, the SKREEM performs a self-test to decide whether the SKIS is in good operating condition and whether a valid key is present in the ignition lock cylinder. The SKREEM then sends the proper lamp-ON or lamp-OFF message to the ElectroMechanical Instrument Cluster (EMIC). If the cluster flashes the security indicator upon ignition ON, or turns ON the security indicator solid after the bulb test, it indicates that a SKIS malfunction has occurred or that the SKIS is ineffective.

For proper diagnosis of the VTSS, the SKIS, the SKREEM, the TIPM, the EMIC, the CAN data bus or the electronic communication related to security indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.