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P0181


P0181 FTT SENSOR





Description





The fuel tank temperature sensor is used to detect the fuel temperature inside the fuel tank. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the fuel temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.









DTC Logic

DTC DETECTION LOGIC

DTC Detection Logic:






DTC CONFIRMATION PROCEDURE
1.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 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to P0181.
NO - GO TO 3.
3.CHECK ENGINE COOLANT TEMPERATURE
With CONSULT-III
1. Select "COOLAN TEMP/S" in "DATA MONITOR" with CONSULT-III.
2. Check "COOLAN TEMP/S" value.
With GST
Follow the procedure "With CONSULT-III" above.
"COOLAN TEMP/S" less than 60�C (140�F)?
YES - INSPECTION END
NO - GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
With CONSULT-III
1. Cool engine down until "COOLAN TEMP/S" is less than 60�C (140�F).
2. Wait at least 10 seconds.
3. Check 1st trip DTC.
With GST
Follow the procedure "With CONSULT-III" above.
Is 1st trip DTC detected?
YES - Go to P0181.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection M95. Refer to Ground Inspection in Circuit Inspection.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connection.
2.CHECK DTC WITH "UNIFIED METER AND A/C AMP."
Refer to Diagnosis System (Unified Meter and A/C AMP.).
Is the inspection result normal?
YES - GO TO 3.
NO - Go to Component Function Check.
3.CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect "fuel level sensor unit and fuel pump (main)" harness connector.
3. Turn ignition switch ON.
4. Check the voltage between "fuel level sensor unit and fuel pump (main)" harness connector and ground.





Is the inspection result normal?
YES - GO TO 5.
NO - GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M7, B1
- Harness for open or short between ECM and "fuel level sensor unit and fuel pump (main)"
- Repair open circuit, 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 the continuity between "fuel level sensor unit and fuel pump (main)" harness connector and "unified meter and A/C amp." harness connector.





4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 7.
NO - GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M7, B1
- Harness for open or short between "fuel level sensor unit and fuel pump (main)" and "unified meter and A/C amp."
- Repair open circuit, short to ground or short to power in harness or connector.
7.CHECK FUEL TANK TEMPERATURE SENSOR
Refer to P0181.
Is the inspection result normal?
YES - GO TO 8.
NO - Replace "fuel level sensor unit and fuel pump (main)".
8.CHECK INTERMITTENT INCIDENT
Refer to Intermittent Incident.
- INSPECTION END




Component Inspection
1.CHECK FUEL TANK TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect "fuel level sensor unit and fuel pump (main)" harness connector.
3. Remove fuel level sensor unit.





4. Check resistance between "fuel level sensor unit and fuel pump
(main)" terminals by heating with hot water as shown in the figure.





Is the inspection result normal?
YES - INSPECTION END
NO - Replace "fuel level sensor unit and fuel pump (main)".