System Tests: Communications: Notes

CAUTION: Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector or battery.

NOTE: Perform BODY VERIFICATION TEST after repairs.

Connect scan tool to Data Link Connector (DLC) to retrieve messages. If scan tool message is blank, disconnect scan tool. Ensure ground circuit has continuity at DLC terminal No. 4. Ensure 12 volts exists at DLC terminal No. 16. Check for power supply at DLC terminal No. 16 from Power Distribution Center (PDC) fuse No. 12. Try another scan tool and/or cable. If scan tool Diagnostic Trouble Codes (DTC) or symptom fault message is present, see following DTC message index or symptoms index for messages displayed. Proceed to appropriate procedure for DTC or fault message(s) present. See DTC MESSAGE INDEX DIRECTORY and SYMPTOMS INDEX DIRECTORY tables.