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Home >> Nissan-Datsun >> 2008 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - Component Testing (Qr25DE) >> Fuel Injector >> Diagnostic Procedure
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Diagnostic 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-III 

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

    Without CONSULT-III 

    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 MOTOR CO., U.S.A.

    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).
      Fig 2: Identifying Fuel Injector Harness Connector
      G04925992Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between fuel injector terminal 1 and ground with CONSULT-III or tester.

      Voltage: Battery voltage 

      Fig 3: Checking Voltage Between Fuel Injector Terminal 1 And Ground
      G04900780Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  5.

    NG: GO TO 4.

  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E3, F2
    • 10A 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.

  7. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END