LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2005 >> FX35 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System - VQ35DE >> DTC P0181: FTT Sensor >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground three screws on the body. Refer to "GROUND INSPECTION  ".
    Fig 1: Retightening Ground Three Screws On Body
    G02360465Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 2.
    2. NG: Repair or replace ground connections.
  2. CHECK DTC WITH "UNIFIED METER AND A/C AMP." 

    Refer to "SELF-DIAGNOSTIC RESULTS ".

    OK or NG 

    1. OK: GO TO 3.
    2. 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.
    3. Turn ignition switch ON.
      Fig 2: Disconnecting "Fuel Level Sensor Unit And Fuel Pump" Harness Connector
      G02360466Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Check voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-II or tester.
      1. Voltage: Approximately 5V 

    OK or NG 

    1. OK: GO TO  5 .
    2. NG: GO TO 4.
    Fig 3: Checking Voltage Between "Fuel Level Sensor Unit And Fuel Pump" Terminal 4 And Ground
    G02360467Courtesy of NISSAN MOTOR CO., U.S.A.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B1, M11
    • 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.
  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 36. Refer to WIRING DIAGRAM  .
      1. Continuity should exist. 
    4. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO  7 .
    2. NG: GO TO 6.
  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors B1, M11
    • Harness for open or short between "fuel level sensor unit and fuel pump" and "unified meter and A/C amp."
      1. : 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 

    1. OK: GO TO 8.
    2. NG: Replace fuel level sensor unit.
  8. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  ".

    1. : INSPECTION END 
scientia non olet · About LEMON Manuals