With engine idling, listen to each injector for operating sound. Each injector should click. If each injector clicks, test is complete. If any injector does not click, go to next step.
Turn ignition off. Disconnect injector sub-harness connectors. See Fig 1 and Fig 2 . Turn ignition on. Measure voltage between ground and right bank injector sub-harness connector terminal No. 4 (White wire). Measure voltage between ground and left bank injector sub-harness connector terminal No. 5 (White wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See WIRING DIAGRAMS article.
Turn ignition off. Reconnect right bank injector sub-harness connector. Disconnect all right bank injectors and ECM harness connectors. See Figure. Check continuity of the following:
- Between injector No. 2 harness connector terminal No. 1 (Red/Black wire) and ECM harness connector terminal No. 7 (Light Green wire).
- Between injector No. 4 harness connector terminal No. 1 (Red/White wire) and ECM harness connector terminal No. 6 (Gray/Blue wire).
- Between injector No. 6 harness connector terminal No. 1 (Red/Green wire) and ECM harness connector terminal No. 4 (White/Red wire).
- Between injector No. 8 harness connector terminal No. 1 (Red/Blue wire) and ECM harness connector terminal No. 2 (Red/White wire).
- Red/Black wire between left bank injector sub-harness connector terminal No. 3 and ECM harness connector terminal No. 1.
- Red/Blue wire between left bank injector sub-harness connector terminal No. 2 and ECM harness connector terminal No. 14.
- Purple/Red wire between left bank injector sub-harness connector terminal No. 1 and ECM harness connector terminal No. 5.
- Red/Yellow wire between left bank injector sub-harness connector terminal No. 6 and ECM harness connector terminal No. 3.
See Figure. Also check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
Remove intake manifold collector. See 4.1L - Q45 article in ENGINES. Disconnect all left bank injector harness connectors. Check continuity between the following:
- Red/Black wire between left bank injector sub-harness connector terminal No. 3 and injector No. 1 harness connector terminal No. 1.
- Red/White wire between left bank injector sub-harness connector terminal No. 2 and injector No. 3 harness connector terminal No. 1.
- Red/Green wire between left bank injector sub-harness connector terminal No. 1 and injector No. 5 harness connector terminal No. 1.
- Red/Blue wire between left bank injector sub-harness connector terminal No. 6 and injector No. 7 harness connector terminal No. 1.
Also check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
Check fuel injector. See FUEL INJECTOR . Replace if necessary. If fuel injector is okay, go to next step.
No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.

Fig 1: Locating Left Bank Injector Sub-Harness Connector (Q45)

Courtesy of NISSAN MOTOR CO., U.S.A.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Fuel Injector Circuits (Q45)

Use the Manual With the Right Hardware

When to See a Mechanic

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