VCM Class 2 Data Line
- Ensure there is proper connection between scan tool and DLC and there are no loose or missing DLC terminals.
- If the VCM is not accessible with a scan tool, check for an open in circuit 1807 between DLC terminal No. 2 and the VCM.
- Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. 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. These circuits may be intermittent or resistive when loaded and should be checked by monitoring the voltage drop with the system under load.
- Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, go to CLASS 2 DATA LINE DIAGNOSIS under SYSTEM TESTS.