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Home >> Nissan-Datsun >> 2012 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component Testing (Qr25DE) >> Fuel Injector >> Diagnosis Procedure
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Diagnosis Procedure

  1. INSPECTION START

    Turn ignition switch to START.

    Is any cylinder ignited? 

    Yes or No 

    Yes >> GO TO 2.

    No >> GO TO  3.

  2. CHECK OVERALL FUNCTION

    With CONSULT 

    1. Start engine.
    2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT.
    3. Check that each circuit produces a momentary engine speed drop.

    Without CONSULT 

    1. Start engine.
    2. Listen to each fuel injector operating sound.

    Clicking noise should be heard  .

    Fig 1: Checking Fuel Injector Operating Sound
    G04875112Courtesy of NISSAN NORTH AMERICA, INC.

    OK or NG 

    OK: INSPECTION END 

    NG: GO TO 3.

  3. CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect fuel injector harness connector (1).
      • ←: Vehicle front
    3. Turn ignition switch ON.
      Fig 2: Identifying Fuel Injector Harness Connector
      G04925992Courtesy of NISSAN NORTH AMERICA, INC.
    4. Check voltage between fuel injector terminal 1 and ground with CONSULT or tester.

    Voltage: Battery voltage 

    Fig 3: Checking Fuel Injector Power Supply Circuit
    G04900780Courtesy of NISSAN NORTH AMERICA, INC.

    OK or NG 

    OK: GO TO  5.

    NG: GO TO 4.

  4. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E3, F2
    • 10 A fuse
    • Harness for open or short between fuel injector and fuse

    Repair open circuit or short to ground or short to power in harness or connectors.

  5. CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between fuel injector terminal 2 and ECM terminals 29, 30, 31, 32. Refer to Wiring Diagram .

      Continuity should exist  .

    4. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO 6.

    NG: Repair open circuit or short to ground or short to power in harness or connectors.

  6. CHECK FUEL INJECTOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 7.

    NG: Replace malfunctioning fuel injector. Refer to , "REMOVAL AND INSTALLATION ".

  7. CHECK INTERMITTENT INCIDENT

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    INSPECTION END