Diagnostic Procedure
- Measure voltage (backprobe) between ground and terminal No. 1 (White/Black wire) of back door key lock and unlock switch harness connector. When key in lock cylinder is turned to unlock position, 10-14 volts should be present. When lock cylinder is in neutral position, voltage should not be present. If voltage is not as specified, go to next step. If voltage is as specified, replace theft deterrent ECU. Retest system.
- Remove back door key lock and unlock switch harness connector. Check continuity between terminals No. 1 (White/Black wire) and No. 2 (Brown/White wire) of back door key lock and unlock switch. Continuity should be present when key in lock cylinder is turned to unlock position. No continuity should be present when lock cylinder is in neutral position. If continuity is as specified, go to next step. If continuity is not as specified, replace back door key lock and unlock switch.
- Check continuity of Brown/White wire between terminal No. 5 of theft deterrent ECU harness connector and terminal No. 2 of back door key lock and unlock switch harness connector. See Figure. Check continuity of Yellow/Black wire between terminal No. 3 of theft deterrent ECU harness connector and terminal No. 3 of back door key lock and unlock switch harness connector. Continuity should be present in both wires. Repair as necessary. If continuity is present, go to next step.
- Check continuity between ground and terminal No. 1 (White/Black wire) of back door key lock and unlock switch harness connector. If continuity is not present, repair open in White/Black wire between back door key lock and unlock switch and ground (located at left side of back door). If continuity is present, replace theft deterrent ECU. Retest system.