Trunk / Liftgate Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. Disconnect and isolate the battery negative cable. Disconnect the liftgate latch pigtail wire connector from the liftgate wire harness connector. Check for continuity between the ground circuit cavity in the liftgate wire harness connector and a good ground. There should be continuity. If OK, go to Step 2. If not OK, repair the open ground circuit to ground as required.
2. Check for continuity between the ground circuit cavity and the liftgate ajar switch sense circuit cavity in the liftgate latch pigtail wire connector. There should be continuity with the liftgate opened, and no continuity with the liftgate closed. If OK, go to Step 3. If not OK, replace the faulty liftgate latch unit.
3. Disconnect the body wire harness connector (Connector C2) for the Central Timer Module (CTM) from the CTM connector receptacle. Check for continuity between the liftgate ajar switch sense circuit cavity of the body wire harness connector (Connector C2) and a good ground. There should be no continuity. If OK, go to Step 4. If not OK, repair the shorted liftgate ajar switch sense circuit between the liftgate latch and the CTM as required.
4. Check for continuity between the liftgate ajar switch sense circuit cavities of the body wire harness connector (Connector C2) and the liftgate wire harness connector for the liftgate latch. There should be continuity. If OK, use a DRB III scan tool to diagnose the CTM. Refer to the appropriate diagnostic procedures. If not OK, repair the open liftgate ajar switch sense circuit between the liftgate latch and the CTM as required.