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Home >> Infiniti >> 2011 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P0137 Through P0456 >> DTC P0181: FTT Sensor >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK DTC WITH COMBINATION METER

    Refer to "CONSULT-III FUNCTION ".

    Is the inspection result normal? 

    YES: GO TO 2.

    NO: Proceed to "COMPONENT FUNCTION CHECK ".

  2. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
    1. Turn ignition switch OFF.
    2. Disconnect "fuel level sensor unit and fuel pump" harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between "fuel level sensor unit and fuel pump" harness connector and ground.
      VOLTAGE SPECIFICATION

      Fuel level sensor unit and fuel pump Ground Voltage (V)
      Connector Terminal
      C5 4 Ground Approx. 5

      Is the inspection result normal? 

      YES: GO TO  4.

      NO: GO TO 3.

  3. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
    • Loose or poor connection for each connector and harness

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

  4. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect "combination meter" harness connector.
    3. Check the continuity between "fuel level sensor unit and fuel pump" harness connector and "combination meter" harness connector.
      CONTINUITY SPECIFICATION

      Fuel level sensor unit and fuel pump Combination meter Continuity
      Connector Terminal Connector Terminal
      C5 5 M34 24 Existed
    4. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  6.

      NO: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between "fuel level sensor unit and fuel pump" and "combination meter"
    • Loose or poor connection for each connector and harness

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

  6. CHECK FUEL TANK TEMPERATURE SENSOR

    Refer to "COMPONENT INSPECTION (FUEL TANK TEMPERATURE SENSOR) ".

    Is the inspection result normal? 

    YES: GO TO 7.

    NO: Replace fuel level sensor unit and fuel pump. Refer to "REMOVAL AND INSTALLATION ".

  7. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT ".

    INSPECTION END

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