Sentry Key Immobilizer Module (Skim) Bulb Check

Note operation of Vehicle Theft Security System (VTSS) LED located on top of instrument panel during check. Turn ignition on. SKIM should send message to BCM to turn VTSS LED on for about 3 seconds. After 3-second bulb check, SKIM sends message to turn VTSS LED off for about one second. If VTSS LED comes on and stays on after one second off period, there is a malfunction in the Sentry Key Immobilizer System (SKIS). If VTSS LED flashes and a single chime tone is heard, an invalid key was used to attempt vehicle start-up.