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Home >> Infiniti >> 2010 >> M45 x >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0460 To P1421 >> DTC P1220 Fuel Pump Control Module (FPCM) >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK GROUND CONNECTIONS
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground screws on the body.

    Refer to "GROUND INSPECTION ".

    Fig 1: Identifying Body Ground (M70 And M16)
    G06303326Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CHECK FPCM POWER SUPPLY CIRCUIT
    1. Disconnect fuel pump control module (FPCM) harness connector.
      Fig 2: Identifying Fuel Pump Control Module (FPCM) Harness Connector
      G06303327Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Turn ignition switch ON.
    3. Check voltage between FPCM terminal 2 and ground with CONSULT-III or tester.

    Voltage: Battery voltage 

    OK or NG 

    OK: GO TO  4.

    NG: GO TO 3.

    Fig 3: Checking Voltage Between FPCM Terminal 2 And Ground
    G05210004Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E106, B4
    • Harness for open or short between FPCM and harness connector B4

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

  4. CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT-I
    1. Turn ignition switch OFF.
    2. Check harness continuity between FPCM terminal 3 and ground.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should exist  .

    3. Also check harness for short to power.

    OK or NG 

    OK: GO TO 5.

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

  5. CHECK FPCM GROUND CIRCUIT FOR OPEN AND SHORT-II
    1. Disconnect "fuel level sensor unit and fuel pump" harness connector (1).
      • Illustration shows the view with rear seat cushion and inspection hole cover (RH) removed.
      • Vehicle Front
      Fig 4: Identifying Fuel Pump Harness Connector
      G06303329Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Disconnect dropping resistor harness connector.
      Fig 5: Identifying Dropping Resistor Harness Connector
      G06303330Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check harness continuity between the following;

      "fuel level sensor unit and fuel pump" terminal 3 and dropping resistor terminal 2,

      FPCM terminal 4 and dropping resister terminal 2.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should exist  .

    4. Check harness continuity between the following;

      "fuel level sensor and fuel pump" terminal 3 and ground,

      FPCM terminal 4 and ground.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should not exist  .

    5. Also check harness for short to power.

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 6.

  6. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors B434, B65
    • Harness for open or short between "fuel level sensor unit and fuel pump" and dropping resistor
    • Harness for open or short between FPCM and dropping resistor
    • Harness for open or short between "fuel level sensor unit and fuel pump" and ground
    • Harness for open or short between FPCM and ground

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

  7. CHECK FPCM INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 38 and FPCM terminal 4.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should exist  .

    3. Check harness continuity between ECM terminal 38 and ground.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should not exist  .

    4. Also check harness for short to power.

    OK or NG 

    OK: GO TO  9.

    NG: GO TO 8.

  8. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors B2, M13
    • Harness connectors M72, F102
    • Harness for open or short between ECM and FPCM

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

  9. CHECK FPCM OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Check harness continuity between ECM terminal 39 and FPCM terminal 1.

      Refer to SYSTEM WIRING DIAGRAMS article.

      Continuity should exist  .

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

    OK or NG 

    OK: GO TO  11.

    NG: GO TO 10.

  10. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors B2, M13
    • Harness connectors M72, F102
    • Harness for open or short between ECM and FPCM

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

  11. CHECK FPCM

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 12.

    NG: Replace FPCM.

  12. CHECK INTERMITTENT INCIDENT

    Refer to "DIAGNOSIS PROCEDURE ".

    INSPECTION END 

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