P0181

P0181 FTT SENSOR





Component 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]






CAUTION:
Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.




On Board Diagnosis Logic









DTC Confirmation Procedure

NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next step.
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.

WITH CONSULT-III
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
If 1st trip DTC is detected, go to P0181.
If 1st trip DTC is not detected, go to following step.
3. Select "DATA MONITOR" mode with CONSULT-III.
4. Check "COOLAN TEMP/S" value.
If "COOLAN TEMP/S" is less than 60�C (140�F), the result will be OK.
If "COOLAN TEMP/S" is above 60�C (140�F), go to the following step.
5. Cool engine down until "COOLAN TEMP/S" is less than 60�C (140�F).
6. Wait at least 10 seconds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to P0181.

WITH GST
Follow the procedure "WITH CONSULT-III" above.




Diagnosis Procedure
1.CHECK COMBINATION METER FUNCTION
Work Flow.
OK or NG
OK - GO TO 2.
NG - Go to Component Function Check.
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 voltage between "fuel level sensor unit and fuel pump" terminal 4 and ground with CONSULT-III or tester.

Voltage: Approximately 5V

OK or NG
OK - GO TO 4.
NG - GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E41, C1
- Harness for open or short between ECM and "fuel level sensor unit and fuel pump"
- Repair 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 harness continuity between "fuel level sensor unit and fuel pump" terminal 3 and combination meter terminal 9. Refer to Wiring Diagram.

Continuity should exist.

4. Also check harness for short to ground and short to power.
OK or NG
OK - GO TO 6.
NG - GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E41, C1
- Harness connectors E152, M31
- 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.
OK or NG
OK - GO TO 7.
NG - Replace fuel level sensor unit.
7.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
- INSPECTION END




Component Inspection

FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.





2. Check resistance between "fuel level sensor unit and fuel pump" terminals 3 and 4 by heating with hot water or heat gun as shown in the figure.