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Home >> Infiniti >> 2005 >> G35 x >> Repair and Diagnosis >> Engine Performance >> Engine Control System - Sedan >> 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 two ground screws on the body. Refer to "Ground Inspection ".
      Fig 1: Checking Ground Connections
      G02348493Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace ground connections.
  2. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect "fuel level sensor unit and fuel pump" harness connector.
    2. Turn ignition switch ON.
      Fig 2: Locating Fuel Level Sensor & Fuel Pump Harness Connector
      G02348494Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-II or tester.

      Voltage: Approximately 5V 

    OK or NG 

    1. OK: GO TO  4.
    2. NG: GO TO 3.
      Fig 3: Checking Voltage Between Fuel Level Sensor Unit & Fuel Pump Terminal 4 & Ground
      G02348495Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors M72, F102
    • Harness connectors B1, M12
    • Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
    1. : Repair open circuit or 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. Check harness continuity between "fuel level sensor unit and fuel pump" terminal 5 and ground. Refer to Wiring Diagram.

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO  6.
    2. NG: GO TO 5.
  5. DETECT MALFUNCTIONING PART 

    Check the following

    • Harness connectors B1, M12
    • Harness for open or short between "fuel level sensor unit and fuel pump" and ground.
    1. : Repair open circuit or short to power in harness or connector.
  6. CHECK FUEL TANK TEMPERATURE SENSOR 

    Refer to "Component Inspection ".

    OK or NG 

    1. OK: GO TO 7.
    2. NG: Replace fuel level sensor unit.
  7. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. : INSPECTION END