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Home >> Infiniti >> 2006 >> M35 Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (VQ35DE) - DTCS P1220 To P2A03 >> DTC P1220 Fuel Pump Control Module (FPCM) >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten two ground screws on the body. Refer to , "GROUND INSPECTION ".
    Fig 1: Checking Ground Connections
    G04138775Courtesy 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 Harness Connector
      G04138776Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Turn ignition switch ON.
    3. Check voltage between FPCM terminal 2 and ground with CONSULT-II 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 With CONSULT-II Or Tester
    G04138777Courtesy 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-I FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between FPCM terminal 3 and ground. Refer to Wiring Diagram .

      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-II FOR OPEN AND SHORT 
    1. Disconnect harness connectors B162, B64.
    2. Disconnect dropping resistor harness connector.
      Fig 4: Identifying Dropping Resistor Harness Connector
      G04138778Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check harness continuity between the following; harness connector B64 terminal 1 and dropping resistor terminal 2, FPCM terminal 4 and dropping resister terminal 2. Refer to Wiring Diagram .

      Continuity should exist. 

    4. Check harness continuity between the following; harness connector B64 terminal 1 and ground, FPCM terminal 4 and ground. Refer to Wiring Diagram .

      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 B162, B64
    • Harness for open or short between harness connector B64 and dropping resistor
    • Harness for open or short between FPCM and dropping resistor
    • Harness for open or short between harness connector B64 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 Wiring Diagram .

      Continuity should exist. 

    3. Check harness continuity between ECM terminal 38 and ground. Refer to Wiring Diagram .

      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 Wiring Diagram .

      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 , "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END