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Home >> Infiniti >> 2008 >> M45 Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (VK45DE) - DTCS P0171 Through P0456 >> DTC P0181 FTT Sensor >> Diagnostic Procedure
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Diagnostic 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 Body Ground M16 Screws
      G05210672Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  2.

    NG: Repair or replace ground connections.

  2. CHECK DTC WITH "UNIFIED METER AND A/C AMP." 

    Refer to "SELF-DIAG RESULTS ".

    OK or NG 

    OK: GO TO  3.

    NG: GO TO "FUEL LEVEL SENSOR SIGNAL INSPECTION ".

  3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. 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
    3. Turn ignition switch ON.
      Fig 2: Identifying Fuel Level Sensor Unit And Fuel Pump Harness Connector
      G05209765Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-III or tester.

      Voltage: Approximately 5V 

    OK or NG 

    OK: GO TO  5.

    NG: GO TO 4.

    Fig 3: Checking Voltage Between Fuel Level Sensor Unit And Fuel Pump Terminal 4 And Ground
    G04875130Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M66, B418
    • Harness for open or short between ECM and "fuel level sensor unit and fuel pump"

    >> Repair open circuit or short to ground or short to power in harness or connector.

  5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect "unified meter and A/C amp." harness connector.
    3. Check harness continuity between "fuel level sensor unit and fuel pump" terminal 5 and "unified meter and A/C amp." terminal 58.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

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

    OK or NG 

    OK: GO TO  7.

    NG: GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M66, B418
    • Harness for open or short between "fuel level sensor unit and fuel pump" and "unified meter and A/C amp."

    >> Repair open circuit or short to ground or short to power in harness or connector.

  7. CHECK FUEL TANK TEMPERATURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 8.

    NG: Replace "fuel level sensor unit and fuel pump".

  8. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    >> INSPECTION END 

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