2006 Infiniti QX56 RWDFACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

  1. CHECK OVERALL FUNCTION 
    1. Turn ignition switch ON.
    2. Pinch fuel feed hose with two fingers.

      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.
      Fig 1: Pinching Fuel Feed Hose
      G04133242Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Turn ignition switch ON.
    4. Check voltage between ECM terminal 113 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

    OK or NG 

    1. OK : GO TO  5.
    2. NG : GO TO 3.
      Fig 2: Identifying Voltage Between ECM Terminal 113 And Ground
      G04133243Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II 

    Check voltage between IPDM E/R terminal 46 and ground with CONSULT-II or tester.

    Voltage: Battery voltage 

    OK or NG 

    1. OK : GO TO 4.
    2. NG : GO TO  13.
      Fig 3: Identifying Voltage Between IPDM E/R Terminal 46 And Ground
      G04133244Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART 

    Check harness for open or short between IPDM E/R and ECM.

    1. : Repair harness or connectors.
  5. CHECK CONDENSER-2 POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Disconnect condenser-2 harness connector.
    4. Turn ignition switch ON.
      Fig 4: Identifying Condenser-2 Harness Connector
      G04133245Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Check voltage between condenser-2 terminal 1 and ground with CONSULT-II or tester.

      Voltage: Battery voltage should exist for 1 second after ignition switch is turned ON. 

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

    OK or NG 

    1. OK : GO TO  8.
    2. NG : GO TO 6.
      Fig 5: Identifying Voltage Between Terminal 1 And Ground
      G04075312Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK 15A FUSE 
    1. Turn ignition switch OFF.
    2. Disconnect 15A fuse.
    3. Check 15A fuse.

    OK or NG 

    1. OK : GO TO 7.
    2. NG : Replace fuse.
  7. CHECK CONDENSER-2 POWER SUPPLY CIRCUIT-II FOR OPEN AND SHORT 
    1. Disconnect IPDM E/R harness connector E119.
    2. Check harness continuity between IPDM E/R terminal 13 and condenser-2 terminal 1.

      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  13.
    2. NG : Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK CONDENSER-2 GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Check harness continuity between condenser-2

      + terminal 2 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    2. Also check harness for short to power.

    OK or NG 

    1. OK : GO TO 9.
    2. NG : Repair open circuit or short to power in harness or connectors.
  9. CHECK CONDENSER-2 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK : GO TO 10.
    2. NG : Replace condenser-2.
  10. CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect " fuel level sensor unit and fuel pump" harness connector.
    3. Disconnect IPDM E/R harness connector E119.
    4. Check harness continuity between IPDM E/R terminal 13 and " fuel level sensor unit and fuel pump" terminal 1, "fuel level sensor unit and fuel pump" terminal 3 and ground.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    5. Also check harness for short to ground and short to power.
      Fig 6: Identifying " Fuel Level Sensor Unit And Fuel Pump" Connector
      G04133247Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK : GO TO  12.
    2. NG : GO TO 11.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E41, C1
    • Harness for open or short between fuel pump and IPDM E/R
    • Harness for open or short between fuel pump and ground
      1. : Repair open circuit or short to ground or short to power in harness or connectors.
  12. CHECK FUEL PUMP 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK : GO TO 13.
    2. NG : Replace " fuel level sensor unit and fuel pump".
  13. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    OK or NG 

    1. OK : Replace IPDM E/R.
    2. NG : Repair or replace harness or connectors.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.