P0125

DTC P0125 ECT SENSOR







Component Description

NOTE: If DTC P0125 is displayed with P0117, P0118, first perform trouble diagnosis for EC-207, "DTC P0117, P0118 ECT SENSOR". P0117

The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant 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.

CAUTION: Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the ECM's transistor. Use ground other than ECM, such as body ground.




On Board Diagnosis Logic

DTC Confirmation Procedure

CAUTION: Be careful not to overheat engine.

NOTE: If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

WITH CONSULT-II
1. Turn ignition switch ON.




2. Select "DATA MONITOR" mode with CONSULT-II.
3. Check that "COOLAN TEMP/S" is above 10 °C (50 °F).
If it is above 10 °C (50 °F), the test result will be OK. If it is below 10 °C (50 °F), go to following step.

4. Start engine and run it for 65 minutes at idle speed.
If "COOLAN TEMP/S" increases to more than 10 °C (50 °F) within 65 minutes, stop engine because the test result will be OK.
5. If DTC is detected, go to "Diagnostic Procedure" below.

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

Diagnostic Procedure (Steps 1 - 3):

Diagnostic Procedure (Step 4):

Diagnostic Procedure

Component Inspection







ENGINE COOLANT TEMPERATURE SENSOR
Check resistance as shown in the figure.
If NG, replace engine coolant temperature sensor.