P0125

P0125 ECT SENSOR

Description

NOTE: If DTC P0125 is displayed with P0117, P0118, first perform the trouble diagnosis for DTC P0117, P0118.




COMPONENT DESCRIPTION
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.

Reference Data:

CAUTION: Do not 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 the ECM terminals, such as the ground.

On Board Diagnosis Logic
Malfunction is detected when voltage sent to ECM from the sensor is not practical, even when some time has passed after starting the engine, or engine coolant temperature is insufficient for closed loop fuel control.

POSSIBLE CAUSE
- Harness or connectors
(High resistance in the circuit)

- Engine coolant temperature sensor
- Thermostat

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 5 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 1st trip DTC is detected, go to "Diagnostic Procedure" below.

With GST
Follow the procedure "With CONSULT-II".

EC-ECTS-01:

Wiring Diagram


Diagnostic Procedure

Step 1 - 3:

Step 4 - 6: