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Home >> Nissan-Datsun >> 2004 >> Pathfinder LE, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System >> Fuel Pump >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK OVERALL FUNCTION 
    1. Turn ignition switch "ON".
    2. Pinch fuel feed hose with two fingers.
      Fig 1: Pinching Fuel Feed Hose
      G00781345Courtesy of NISSAN MOTOR CO., U.S.A.

    Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned "ON". 

    OK or NG 

    1. OK INSPECTION END 
    2. NG GO TO 2.
  2. CHECK FUEL PUMP RELAY POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch "OFF".
    2. Disconnect fuel pump relay.

      Behind the luggage room trim LH side 

      Fig 2: Identifying Fuel Pump Relay
      G00781346Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch "ON".
    4. Check voltage between terminals 1, 3 and ground with CONSULT-II or tester.
      Fig 3: Checking Voltage Between Terminals 1, 3 And Ground
      G00781347Courtesy of NISSAN MOTOR CO., U.S.A.

    Voltage: Battery voltage 

    OK or NG 

    1. OK GO TO  4 .
    2. NG GO TO 3.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector M10
    • 15A fuse in fuse block (J/B)
    • Harness connectors M2, B1
    • Harness for open or short between fuse and fuel pump relay and fuse
    1. Repair harness or connectors.
  4. CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch "OFF".
    2. Disconnect fuel pump harness connector.
      Fig 4: Disconnecting Fuel Pump Harness Connector
      G00781348Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check harness continuity between fuel pump terminal 2 and body ground, fuel pump terminal 1 and fuel pump relay terminal 5. Refer to WIRING DIAGRAM  .

      Continuity should exist. 

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

    OK or NG 

    1. OK GO TO  6 .
    2. NG GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B24, D101
    • Harness connectors D106, D206
    • Harness for open or short between fuel pump relay and fuel pump
    • Harness for open between fuel pump and ground
    1. Repair open circuit or short to ground or short to power in harness or connectors.
  6. CHECK FUEL PUMP RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 113 and fuel pump relay terminal 2. Refer to WIRING DIAGRAM  .

      Continuity should exist. 

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

    OK or NG 

    1. OK GO TO  8 .
    2. NG GO TO 7.
  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B1, M2
    • Harness connectors M32, F23
    • Harness for open or short between ECM and fuel pump relay
    1. Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK FUEL PUMP RELAY 

    With CONSULT-II 

    1. Reconnect fuel pump relay, fuel pump harness connector and ECM harness connector.
    2. Turn ignition switch "ON".
    3. Turn fuel pump relay "ON" and "OFF" in "ACTIVE TEST" mode with CONSULT-II and check operating sound.
      Fig 5: Checking Fuel Pump Relay With CONSULT-II
      G00781349Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    Check continuity between terminals 3 and 5 under the following conditions.

    Fig 6: Checking Fuel Pump Relay Without CONSULT-II
    G00781350Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 7: Fuel Pump Relay Continuity Chart
    G00781351Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK GO TO 9.
    2. NG Replace fuel pump relay.
  9. CHECK FUEL PUMP 
    1. Disconnect fuel pump harness connector.
    2. Check resistance between fuel pump terminals 1 and 2.
      Fig 8: Checking Resistance Between Fuel Pump Terminals 1 And 2
      G00781352Courtesy of NISSAN MOTOR CO., U.S.A.

      Resistance: 0.2 - 5.0 ohm [at 25°C (77°F)] 

    OK or NG 

    1. OK GO TO 10.
    2. NG Replace fuel pump.
  10. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  " .

    1. INSPECTION END