VTSS Does Not Trip From Liftgate

Open liftgate. Ensure liftgate flip-up glass is closed. Using scan tool, select BODY, DOOR MODULES, then INPUT/OUTPUT. Read LIFTGATE SW status. If status is not CLOSED, go to LIFTGATE AJAR CIRCUIT OPEN  under DOOR AJAR SYSTEM. If status is CLOSED, replace Body Control Module (BCM). See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. Perform VEHICLE THEFT SECURITY SYSTEM VERIFICATION TEST  under VERIFICATION TESTS.