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Home >> Nissan-Datsun >> 2024 >> Sentra SR >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (2 Of 2) >> Component/Circuit Diagnosis >> Fuel Injector >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK FUSE 
    1. Turn ignition switch OFF.
    2. Check that the following fuse is not blown (open).
      Fuse No. Capacity
      No. 60 10 A
      No. 64 15 A

    Is the fuse blown (open)?

    >>

    Replace the fuse after repairing the applicable circuit.

    >>

    GO TO 2.

  2. CHECK FUEL INJECTOR DRIVER POWER SUPPLY 
    1. Disconnect ECM harness connector.
    2. Turn ignition switch ON.
    3. Check the voltage between ECM harness connector and ground.
      + - Voltage
      ECM
      Connector Terminal
      F24 3 Ground Battery voltage
      4

    Is the inspection result normal?

    >>

    GO TO 9.

    >>

    GO TO 3.

  3. CHECK FUEL INJECTOR DRIVER POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect direct fuel injector relay 1 and 2 harness connector.
    4. Check the continuity between ECM harness connector and direct fuel injector relay 1 and 2 harness connector.
      ECM Direct fuel injector relay 1 and 2 Continuity
      Connector Terminal Connector Terminal
      F24 3 F60 2 Existed
      4 7
    5. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    >>

    GO TO 4.

    >>

    Repair or replace malfunctioning part.

  4. CHECK DIRECT FUEL INJECTOR RELAY 1 AND 2 POWER SUPPLY (CONTACT SIDE) 

    Check the voltage between fuel injector relay harness connector and ground.

    + - Voltage
    Direct fuel injector relay 1 and 2
    Connector Terminal
    F60 1 Ground Battery voltage
    6

    Is the inspection result normal?

    >>

    GO TO 5.

    >>

    Perform trouble diagnosis for power supply circuit.

  5. CHECK DIRECT FUEL INJECTOR RELAY 1 AND 2 POWER SUPPLY (EXCITATION COIL SIDE) 
    1. Install all removed parts.
    2. Turn ignition switch ON.
    3. Check the voltage between direct fuel injector relay 1 and 2 harness connector and ground.
      + - Voltage
      Direct fuel injector relay 1 and 2
      Connector Terminal
      F60 3 Ground Battery voltage
      8

    Is the inspection result normal?

    >>

    GO TO 7.

    >>

    GO TO 6.

  6. CHECK DIRECT FUEL INJECTOR RELAY 1 AND 2 POWER SUPPLY CIRCUIT (EXCITATION COIL SIDE) 
    1. Turn ignition switch OFF.
    2. Disconnect direct fuel injector relay 1 and 2 harness connector.
    3. Disconnect IPDM E/R harness connector.
    4. Check the continuity between IPDM E/R harness connector and fuel injector relay harness connector.
      IPDM E/R Direct fuel injector relay 1 and 2 Continuity
      Connector Terminal Connector Terminal
      F96 73 F60 3 Existed
      8
    5. Also check harness for short to ground and short to power.

    Is the inspection result normal?

    >>

    Perform trouble diagnosis for power supply circuit.

    >>

    Repair or replace malfunctioning part.

  7. CHECK FUEL INJECTOR RELAY GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect fuel injector relay harness connector.
    3. Check the continuity between direct fuel injector relay 1 and 2 harness connector and ground.
      Direct fuel injector relay 1 and 2 - Continuity
      Connector Terminal
      F60 4 Ground Existed
      9
    4. Also check harness for short to power.

    Is the inspection result normal?

    >>

    GO TO 8.

    >>

    Repair or replace malfunctioning part.

  8. CHECK DIRECT FUEL INJECTOR RELAY 1 AND 2 

    Refer to Component Inspection .

    Is the inspection result normal?

    >>

    Check intermittent incident. Refer to Intermittent Incident .

    >>

    Replace direct fuel injector relay 1 and 2.

  9. CHECK ECM GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Check the continuity between ECM harness connector and ground.
      ECM - Continuity
      Connector Terminal
      F24 5 Ground Existed
      65
      F25 69
      E16 157
      159
      162
    3. Also check harness for short to power.

    Is the inspection result normal?

    >>

    GO TO 10.

    >>

    Repair or replace malfunctioning part.

  10. CHECK FUEL INJECTOR GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between fuel injector harness connector and ECM harness connector.
      Fuel injector ECM Continuity
      Cylinder Connector Terminal Connector Terminal
      1 F18 2 F24 8 Existed
      2 F19 2 7
      3 F20 2 9
      4 F21 2 6
    4. Also check harness for short to ground.

    Is the inspection result normal?

    >>

    GO TO 11.

    >>

    Repair or replace malfunctioning part.

  11. CHECK FUEL INJECTOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    >>

    Check intermittent incident. Refer to Intermittent Incident .

    >>

    Replace malfunctioning fuel injector. Refer to Removal and Installation .

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