P0181
P0181 FTT SensorComponent 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
P0181:
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 SDT
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 FTT Sensor].
If 1st trip DTC is not detected, go to following step.
3. Select "Data list" mode with SDT.
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 FTT Sensor].
WITH GST
Follow the procedure "WITH SDT" above.
Diagnosis Procedure
Step 1-2:
Step 3-7:
Component Inspection
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between "fuel level sensor unit and fuel pump" terminals 2 and 4 by heating with hot water or heat gun as shown in the figure.
