SECURITY Indicator
WARNING: This page is about a different car, the 2003 GMC Sonoma, 2003 GMC Jimmy, 2003 Chevrolet S10 Pickup, and 2003 Chevrolet Blazer. However, it is still accessible from the selected car via links, so may be relevant.
The SECURITY indicator on the instrument cluster is controlled by the VTD system. The SECURITY indicator bulb is located inside the instrument cluster. The SECURITY indicator is controlled by the body control module through the class 2 data line. The VTD system contained in the BCM commands the instrument cluster to control the SECURITY indicator only when the ignition switch is ON. The VTD system uses the indicator as a malfunction indicator.