DTC 0402

COMPONENT DESCRIPTION
The tank fuel 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.




ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.




With Consult
1) Turn ignition switch "ON".
2) Select "DATA MONITOR" mode with CONSULT.
3) Wait at least 10 seconds.
If the result is NG, go to "DIAGNOSTIC PROCEDURE".
If the result is OK, go to following step.
4) Cool engine down until "COOLAN TEMP/S" is less than 90°C (194°F). If "COOLAN TEMP/S" is already less than 90°C (194°F) before step 4), the result will be OK.
5) Wait at least 10 seconds.

OR

With Generic Scan Tool
1) Turn ignition switch "ON" and wait at least 10 seconds.
2) Select "MODE 7" with GST.
If the result is NO, go to "DIAGNOSTIC PROCEDURE".
If the result is OK, go to following step.
3) Select "MODE 1" with GST and check for the engine coolant temperature.
4) Cool engine down until the engine coolant temperature is less than 90°C (194°F). If the temperature is already less than 90°C (194°F) before step 4), the result will be OK.
5) Wait at least 10 seconds.
6) Select "MODE 7" with GST.

OR

Without Scan Tools
1) Turn ignition switch "ON" and wait at least 10 seconds.
2) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
3) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
If the result is NO, go to "DIAGNOSTIC PROCEDURE".
If the result is OK, go to following step.
4) Cool engine down until the voltage between ECM terminal (51) (Engine coolant temperature) and ground becomes more than 1.0 V.
If the voltage is already more than 1.0 V before step 4, the result will be OK.
5) Wait at least 10 seconds.
6) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
7) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.




DIAGNOSTIC PROCEDURE




WIRING DIAGRAM







COMPONENT INSPECTION
Tank Fuel Temperature Sensor
Check resistance by heating with hot water or heat gun as shown in the figure.
If NG, replace tank fuel temperature sensor.