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Home >> Infiniti >> 2019 >> QX50 Essential, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTC/Circuit Diagnosis) (4 Of 12) >> DTC/Circuit Diagnosis >> DTC P0181: FTT Sensor >> DTC Description >> DTC Confirmation Procedure
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DTC Confirmation Procedure

  1. INSPECTION START 

    Is it necessary to erase permanent DTC?

    YES

    GO TO 7.

    NO

    GO TO 2.

  2. PRECONDITIONING 

    If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

    GO TO 3.

  3. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-1 
    1. Turn ignition switch ON and wait at least 10 seconds.
    2. Check 1st trip DTC.

    Is 1st trip DTC detected?

    YES

    Proceed to Diagnosis Procedure .

    NO

    GO TO 4.

  4. CHECK ENGINE COOLANT TEMPERATURE 

    SYMBOL With CONSULT

    1. Select "COOLANT TEMP/S" in "DATA MONITOR" mode of "ENGINE" using CONSULT.
    2. Check "COOLANT TEMP/S" value.

    SYMBOL With GST

    Follow the procedure "With CONSULT" above.

    "COOLANT TEMP/S" less than 60 deg.C (140 deg.F)?

    YES

    To check malfunction symptom before repair: Refer to Intermittent Incident .

    YES

    Confirmation after repair: INSPECTION END

    NO

    GO TO 5.

  5. PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-2 

    SYMBOL With CONSULT

    1. Cool engine down until "COOLANT TEMP/S" is less than 60 deg.C (140 deg.F).
    2. Wait at least 10 seconds.
    3. Check 1st trip DTC.

    SYMBOL With GST

    Follow the procedure "With CONSULT" above.

    Is 1st trip DTC detected?

    YES

    Proceed to Diagnosis Procedure .

    NO

    GO TO 6.

  6. PERFORM COMPONENT FUNCTION CHECK FOR MALFUNCTION B 
    NOTE: Use the component function check to check the overall function of the FTT sensor circuit. During this check, a 1st trip DTC might not be confirmed.
    1. Turn ignition switch OFF.
    2. Disconnect fuel level sensor unit and fuel pump harness connector.
    3. Remove "fuel level sensor unit, fuel filter and fuel pump assembly". Refer to Removal and Installation .
    4. Check resistance between fuel level sensor unit and fuel pump terminals by heating with hot water as shown in the figure.
      GNSJMBIA0167Z-167Courtesy of NISSAN NORTH AMERICA, INC.

      Fuel level sensor unit and fuel pump

      Condition

      Resistance

      Terminal

      5

      6

      Temperature [ deg.C (deg.F)]

      20 (68)

      2.3 - 2.7 kOhm

      50 (122)

      0.79 - 0.90 kOhm

    Is the inspection result normal?

    YES

    To check malfunction symptom before repair: Refer to Intermittent Incident .

    YES

    Confirmation after repair: INSPECTION END

    NO

    Proceed to Diagnosis Procedure .

  7. PRECONDITIONING 

    If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

    TESTING CONDITION:

    • Before performing the following procedure, do not add fuel.
    • Before performing the following procedure, check that fuel level is between 1/4 and 4/4.
    • Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

    GO TO 8.

  8. PERFORM DTC CONFIRMATION PROCEDURE 
    1. Move the vehicle to a cool place.
      NOTE: Cool the vehicle in an environment of ambient air temperature between -10 deg.C (14 deg.F) and 35 deg.C (95 deg.F).
    2. Turn ignition switch OFF and leave the vehicle for 12 hours.
      CAUTION: Never turn ignition switch ON during this procedure.
      NOTE: The vehicle must be cooled with the hood open.
    3. Start engine and let it idle for 5 minutes or more.
      CAUTION: Never turn ignition switch OFF during idling.
    4. Check 1st trip DTC.

    Is 1st trip DTC detected?

    YES

    Proceed to Diagnosis Procedure .

    NO

    To check malfunction symptom before repair: Refer to Intermittent Incident .

    NO

    Confirmation after repair: INSPECTION END