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Nissan Sentra Service Manual: P0181 FTT Sensor

Nissan Sentra Service Manual / Engine / Engine control system / Dtc/circuit diagnosis / P0181 FTT Sensor

DTC Logic

DTC DETECTION LOGIC

DTC No.

 CONSULT screen terms (Trouble diagnosis content)

 DTC detecting condition

 Possible cause
P0181 FTT SENSOR (Fuel temperature sensor ″A″ circuit range/performance) A) Rationally incorrect voltage from the sensor is sent to ECM, compared with the voltage signals from ECT sensor and intake air temperature sensor.
  • Harness or connectors (FTT sensor circuit is open or shorted)
  • FTT sensor
  • Combination meter
B) The comparison result of signals transmitted to ECM from each temperature sensor (IAT sensor, ECT sensor, EOT sensor, and FTT sensor) shows that the voltage signal of the FTT sensor is higher/lower than that of other temperature sensors when the engine is started with its cold state.
  • Harness or connectors (High or low resistance in the FTT sensor circuit)
  • FTT sensor

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 perform the following procedure before conducting the next test.

  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds.

>> 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 EC-256, "Diagnosis Procedure".

NO >> GO TO 4.

4.CHECK ENGINE COOLANT TEMPERATURE

With CONSULT


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

Follow the procedure “With CONSULT” above. With GST


Follow the procedure “With CONSULT” above.

“COOLANT TEMP/S” less than 60°C (140°F)? YES >> INSPECTION END

NO >> GO TO 5.

5.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-2

With CONSULT


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

Follow the procedure “With CONSULT” above. With GST


Follow the procedure “With CONSULT” above.

Is 1st trip DTC detected? YES >> Proceed to EC-256, "Diagnosis Procedure".

NO >> GO TO 6.

6.PERFORM COMPONENT FUNCTION CHECK (FOR MALFUNCTION B)

Perform component function check. Refer to EC-255, "Component Function Check".

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.

Is the inspection result normal? YES >> INSPECTION END

NO >> Proceed to EC-256, "Diagnosis Procedure".

7.PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following procedure before conducting the next test

  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

>> GO TO 8.

8.PERFORM DTC CONFIRMATION PROCEDURE B

  1. Move the vehicle to a cool place.

NOTE:

Cool the vehicle in an environment of ambient air temperature between −10В°C (14В°F) and 35В°C (95В°F).

  1. 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 food open.

  1. Start engine and let it idle for 5 minutes or more.

CAUTION:

Never turn ignition switch OFF during idling.

  1. Check 1st trip DTC.

Is 1st trip DTC detected? YES >> Proceed to EC-256, "Diagnosis Procedure".

NO >> INSPECTION END

Component Function Check

1.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR

  1. Turn ignition switch OFF.
  2. Disconnect fuel level sensor unit and fuel pump harness connector
  3. Remove fuel level sensor unit. Refer to FL-6, "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.


Is the inspection result normal?


Is the inspection result normal? YES >> Check intermittent incident. Refer to GI-39, "Intermittent Incident".

NO >> Proceed to EC-256, "Diagnosis Procedure".

Diagnosis Procedure

1.INSPECTION START

Confirm the detected malfunction (A or B). Refer to EC-254, "DTC Logic".

Which malfunction is detected? A >>GO TO 2.

B >>GO TO 6.

2.CHECK DTC WITH COMBINATION METER

Check DTC with combination meter. Refer to MWI-17, "CONSULT Function (METER/M&A)".

Is the inspection result normal? YES >> GO TO 3.

NO >> Proceed to MWI-58, "Diagnosis Procedure".

3.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR POWER

  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.

Is the inspection result normal?


Is the inspection result normal? YES >> GO TO 5.

NO >> GO TO 4.

4.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR POWER SUPPLY CIRCUIT

  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Check the continuity between fuel level sensor unit and fuel pump harness connector and ECM harness connector.


  1. Also check harness for short to ground and to power.

Is the inspection result normal? YES >> Perform the trouble diagnosis for power supply circuit.

NO >> Repair or replace error-detected parts.

5.CHECK FTT SENSOR GROUND CIRCUIT

  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Check the continuity between fuel level sensor unit and fuel pump harness connector and ECM harness connector.


  1. Also check harness for short to power.

Is the inspection result normal? YES >> GO TO 6.

NO >> Repair or replace error-detected parts.

6.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR

Check the FTT sensor. Refer to EC-257, "Component Inspection".

Is the inspection result normal? YES >> Check intermittent incident. Refer to GI-39, "Intermittent Incident".

NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-6, "Removal and Installation".

Component Inspection

1.CHECK FUEL TANK TEMPERATURE (FTT) SENSOR

  1. Turn ignition switch OFF.
  2. Disconnect fuel level sensor unit and fuel pump harness connector
  3. Remove fuel level sensor unit. Refer to FL-6, "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.


Is the inspection result normal?


Is the inspection result normal? YES >> INSPECTION END

NO >> Replace fuel level sensor unit and fuel pump. Refer to FL-6, "Removal and Installation".

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