Preliminary Inspection
Verify customer complaint by operating suspected malfunctioning system. Visually inspect for obvious signs of mechanical and electrical damage. Repair as necessary. Inspect for faulty fuses, loose or corroded connections, damaged wiring harnesses and/or switches. Repair as necessary. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Repair as necessary. Ensure any aftermarket electronic equipment is properly installed. Repair as necessary. If no problem is found, perform BCM diagnostic circuit check. See BODY CONTROL MODULE (BCM) DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.