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Home >> Infiniti >> 2010 >> M45 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0171 To P0456 >> DTC P0181 FTT Sensor >> 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)
    G06303140Courtesy 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 "CONSULT-III FUNCTION (METER/M&A) ".

    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 5 V 

    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 SYSTEM WIRING DIAGRAMS article.

      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 "DIAGNOSIS PROCEDURE ".

    INSPECTION END 

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