Diagnostic Procedure No. 2: Procedure
WARNING: This page is about a different car, the 2001 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
- Ensure ignition is off. Disconnect IMMU harness connector. Measure voltage between ground and terminal No. 8 (White/Blue wire). See Fig 1 . If battery voltage is present, go to next step. If battery voltage is not present, check fuse No. 36 (10-amp) in underhood fuse block. Replace as needed. If fuse is okay, inspect circuit between fuse and IMMU. Repair as needed. See WIRING DIAGRAMS .
- Turn ignition on. Measure voltage between ground and terminal No. 7 (Brown wire). If battery voltage is present, go to next step. If battery voltage is not present, check fuse No. 20 (10-amp) in junction block fuse block. Replace as needed. If fuse is okay, inspect circuit between fuse and IMMU. Repair as needed.
- Turn ignition off. Check continuity between ground and terminal No. 4 (Black wire). If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between IMMU connector and ground connection. See WIRING DIAGRAMS .
- Turn ignition off. Disconnect ECM harness connector. Check continuity of Brown/Yellow wire between terminal No. 116 on ECM harness connector and terminal No. 1 on IMMU harness connector. See Fig 2 . If continuity exists, go to next step. If continuity does not exist, repair open in Brown/Yellow wire.
- Turn ignition on. Measure voltage on Brown/Yellow wire between ground and terminal No. 116 on ECM harness connector, and terminal No. 1 on IMMU harness connector. If voltage is present, repair Brown/Yellow wire for short to voltage. If voltage is not present, go to next step.
- Turn ignition off. Check continuity of Brown/Yellow wire between ground and terminal No. 116 on ECM harness connector, and terminal No. 1 on IMMU harness connector. If continuity exists, repair Brown/Yellow wire for short to ground. If continuity does not exist, go to next step.
- Using CONSULT scan tool or oscilloscope, check for signal output between ground and terminal No. 116 at ECM. Set voltage range to 5-volt division and duration to 10-millisecond division. Turn ignition on and check for signal within 750 milliseconds. If an approximate 12-volt signal waveform is output, replace IMMU and retest system. If no signal waveform is output, replace ECM and retest.