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Fuel Injector Circuits (Sentra 1.8L)

  1. Start engine. If engine starts and CONSULT-II is available, go to next step. If engine starts and CONSULT-II is not available, go to step  3. If engine does not start, go to step  4.
  2. Start engine. Using CONSULT-II in ACTIVE TEST mode, perform POWER BALANCE test. Each cylinder should drop off when tested. If engine performs as specified, go to step  9. If engine does not perform as specified, go to step  4.
  3. Start engine and listen to each fuel injector. If every injector clicks, system is okay. If any injector does not click, go to next step
  4. Turn ignition off. Disconnect suspect fuel injector harness connector. Turn ignition on. Measure voltage between ground and injector harness connector terminal No. 2 (Black/Red wire). If battery voltage does not exist, go to next step. If battery voltage exists, go to step  6.
  5. Check the following:
    • Check fuse block fuse No. 17 (10-amp).
    • Check for poor, loose, corroded or damaged terminal connections at in-line harness connectors M19 and E108. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
    • Check for poor, loose, corroded or damaged terminal connections at in-line harness connectors E9 and F47.
    • Check for open or short in Black/Red wire between suspect injector and fuse.
    If problem is found, repair as necessary. After repair, retest system.
  6. Turn ignition switch off. Disconnect ECM 121-pin harness connector. For ECM location, see Figure. Check continuity in specified circuits between injector harness connector terminal No. 1 and ECM. See FUEL INJECTOR CIRCUIT IDENTIFICATION (SENTRA)  table. See Figure. Continuity should exist. Also, check harness for short to ground and short to voltage. If problem is found, go to next step. If no problem is found, go to step  8.
    FUEL INJECTOR CIRCUIT IDENTIFICATION (SENTRA)

    Injector No. ECM Terminal No. Wire Color
    1 23 Red/Black
    2 42 Yellow/Black
    3 22 Green/Black
    4 41 Blue/Black
  7. Check for open or short in circuits between suspect injector and ECM. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If problem is found, repair as necessary. If no problem is found, go to next step.
  8. Check fuel injector. See FUEL INJECTOR . If problem is found, replace as necessary. See FUEL RAILS & INJECTORS under FUEL SYSTEM in REMOVAL & INSTALLATION article. If injector is okay, go to next step.
  9. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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