Security Lamp/Indicator: Description and Operation

A security indicator is standard equipment on all instrument clusters. However, on vehicles not equipped with the optional Vehicle Theft Security System (VTSS), this indicator is mechanically disabled. The security indicator is located near the lower edge of the instrument cluster overlay, to the right of center. The security indicator consists of a stencil-like cutout of the word "SECURITY" 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. A red lens behind the cutout in the opaque layer of the overlay causes the "SECURITY" text to appear in red through the translucent outer layer of the overlay when it is illuminated from behind by a Light Emitting Diode (LED) soldered onto the instrument cluster electronic circuit board. The security indicator is serviced as a unit with the instrument cluster.

The security indicator gives an indication to the vehicle operator when the Vehicle Theft Security System (VTSS) is arming or is armed. This indicator is controlled by a hard wired input to the instrument cluster from the Central Timer Module (CTM) on the VTSS indicator driver circuit. The security indicator Light Emitting Diode (LED) receives battery current on the instrument cluster electronic circuit board at all times through a non-switched fused B(+) circuit; therefore, the LED will remain functional regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the CTM. The security indicator will be illuminated for the following reasons:

- VTSS Indication - During the seventeen second VTSS arming function, the CTM will 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 CTM flashes 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 alarm is triggered, the CTM will flash the security indicator at a steady, fast rate for up to eighteen minutes or until the triggering condition is removed, before returning to the slower, armed flash rate.

- 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 CTM provides a hard wired ground input to the instrument cluster circuitry through the VTSS indicator driver circuit whenever the ignition switch is in the Off position and the VTSS is arming, armed, or triggered. For further diagnosis of the security indicator or the instrument cluster circuitry that controls the indicator, (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). The VTSS indicator driver circuit input to the instrument cluster can be diagnosed using conventional diagnostic tools and methods. For proper diagnosis of the VTSS or the CTM, a DRB III scan tool is required. Refer to the appropriate diagnostic information.