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Home >> Infiniti >> 2001 >> Q45 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Fuel System >> Fuel Control >> Fuel Injector Circuits (G20)
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Fuel Injector Circuits (G20)

  1. 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.
  2. Turn ignition off. Disconnect inoperative injector harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 1 (Black/Red 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.
  3. Turn ignition off. Disconnect ECM harness connector. See Figure. Check continuity of the following:
    • Red/Black wire between injector No. 1 harness connector terminal No. 2 and ECM harness connector terminal No. 101.
    • Yellow/Black wire between injector No. 2 harness connector terminal No. 2 and ECM harness connector terminal No. 103.
    • Green/Black wire between injector No. 3 harness connector terminal No. 2 and ECM harness connector terminal No. 105.
    • Blue/Black wire between injector No. 4 harness connector terminal No. 2 and ECM harness connector terminal No. 107.

    See Figure. Also check circuit for short to ground and short to voltage. Repair as necessary and retest system. If circuit is okay, go to next step.

  4. Check fuel injector. See FUEL INJECTOR . Replace, if necessary and retest system. If fuel injector is okay, go to next step.
  5. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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