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Home >> Nissan-Datsun >> 2008 >> Sentra Base, Standard >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS P0172 To P0500 (MR20DE) >> DTC P0181 FTT Sensor >> Diagnostic Procedure

Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground screws on the body.

      Refer to "GROUND INSPECTION ".

      • <=: Vehicle front
      • Body ground (1)

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

    Fig 1: Identifying Body Ground
    G04925191Courtesy of NISSAN MOTOR CO., U.S.A.
  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 (1).
      • <= : Vehicle front
    3. Turn ignition switch ON.
      Fig 2: Identifying Fuel Pump Harness Connector
      G04925355Courtesy 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  4.

    NG: GO TO 3.

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

    Check the following.

    • Harness connectors B9, E13
    • Harness connectors E3, F2
    • 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.

  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 harness continuity between "fuel level sensor unit and fuel pump" terminal 5 and combination meter terminal 4, ECM terminal 60. 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  6.

    NG: GO TO 5.

  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B8, M8
    • Harness connectors B9, E13
    • Harness connectors E3, F2
    • Harness for open or short between "fuel level sensor unit and fuel pump" and combination meter.
    • Harness for open or short between "fuel level sensor unit and fuel pump" and ECM.

    : Repair open circuit or short to ground or short to power in harness or connectors.

  6. CHECK FUEL TANK TEMPERATURE SENSOR 

    Refer to, "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 7.

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

  7. CHECK INTERMITTENT INCIDENT 

    Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    : INSPECTION END 

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