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.
[Reference data]









DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE
1.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 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Turn ignition switch 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" mode with CONSULT-III.
2. Check "COOLAN TEMP/S" indication.
With GST
Follow the procedure "With CONSULT-III" above.
Is "COOLAN TEMP/S" indication 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" indication 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 E38. Intermittent Incident.
Is the inspection result normal?
YES - GO TO 2.
NO - Repair or replace ground connection.
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.
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?
YES - GO TO 4.
NO - GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors B4, M79
- Harness connectors M77, E105
- Harness connectors E8, F1
- 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 the continuity between "fuel level sensor unit and fuel pump" harness connector and ECM harness connector.





4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES - GO TO 6.
NO - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M79, B4
- Harness for open or short between "fuel level sensor unit and fuel pump" and combination meter
- Repair open circuit or short to ground or short to power in harness or connector.
6.CHECK FUEL TANK TEMPERATURE SENSOR
P0181.
Is the inspection result normal?
YES - GO TO 7.
NO - Replace "fuel level sensor unit and fuel pump".
7.CHECK INTERMITTENT INCIDENT
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" harness connector.
3. Remove fuel level sensor unit.
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?
YES - INSPECTION END
NO - Replace "fuel level sensor unit and fuel pump".