Security Indicator
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The security indicator appears on the instrument panel cluster (IPC). If the security indicator flashes or is illuminated continuously during vehicle operation, a malfunction exists within the immobilizer system. The security indicator is a dual purpose indicator. With the ignition OFF, the indicator it is controlled by the body control module (BCM) as a status indicator for the content theft deterrent system. With the ignition ON, it is controlled by the immobilizer system as a fault indicator.