Engine Controls - Tests W/codes: Wiring Infiniti G20 I

ECM HARNESS CONNECTOR

Note. To locate ECM and identify ECM connector terminals (Scheme 55)and (Scheme 56).

Scheme 55

Scheme 56

Scheme 57

Scheme 58

1. Check Power Supply - Turn ignition off and disconnect CKP sensor harness connector. Turn ignition on. Measure voltage between CKP sensor harness connector terminal "a" (Orange wire) and ground. (Scheme 57)and (Scheme 58). If battery voltage is present, go to next step. If battery voltage is not present, verify harness continuity between CKP sensor and ECM (Orange wire), and between CKP sensor and ECCS relay (Orange wire). Repair harness or connectors as necessary.
2. Check Input Signal Circuit - Turn ignition off and disconnect ECM harness connector. Verify harness continuity between CKP sensor harness connector terminal "b" (Blue wire) and ECM harness connector terminals No. 22 and 30 (180 degree signal) and between terminal "c" (Yellow wire) and terminals No. 31 and 40 (one degree signal). (Scheme 55), (Scheme 56) and (Scheme 59). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Component - Inspect CKP sensor. See I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section. Replace CKP sensor if necessary and perform «FINAL CHECK»(ref-17417-S28948843272000122900000).

Scheme 59

Scheme 60

Scheme 61

1. Check Power Supply - Turn ignition off and disconnect MAF sensor harness connector. Turn ignition on. Measure voltage between MAF sensor harness connector terminal "b" (Orange wire) and ground. (Scheme 60)and (Scheme 61). If battery voltage is present, go to next step. If battery voltage is not present, verify harness continuity between MAF sensor and ECM, and MAF sensor and ECCS relay. Repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off and disconnect ECM harness connector. Check continuity between MAF sensor connector terminal "c" (White wire) and ECM terminal No. 17. (Scheme 55), (Scheme 56) and (Scheme 62). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary.
3. Check Input Signal Circuit - Check continuity between MAF sensor connector terminal "d" (Orange wire) and ECM harness connector terminal No. 16. (Scheme 63) If continuity is not present, repair harness or connectors as necessary.
4. Check Component - Inspect MAF sensor. See I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section. Replace MAF sensor if necessary and perform «FINAL CHECK»(ref-17417-S28948843272000122900000).

Scheme 62

Scheme 63

Scheme 64

Scheme 65

1. Check Power Supply - Turn ignition off and disconnect ECT sensor harness connector. Turn ignition on. Measure voltage between ECT sensor harness connector terminal "b" (Blue/Orange wire) and ground. (Scheme 64)and (Scheme 65). If voltage is approximately 5 volts, go to next step. If voltage is not as specified, verify harness continuity between ECT sensor and ECM. Repair harness or connectors as necessary.
2. Check Ground Circuit - Turn ignition off. Check ECT sensor harness continuity between terminal "a" (Black wire) and engine ground. (Scheme 66) If continuity is present, go to next step. If continuity is not present, verify harness continuity between ECT sensor and ECM. Repair harness or connectors as necessary.
3. Check Component - Inspect ECT sensor. See I - SYS/COMP TESTS article in the ENGINE PERFORMANCE Section. Replace ECT sensor if necessary and perform «FINAL CHECK»(ref-17417-S28948843272000122900000).

Scheme 66