Engine Controls For California

DTC P0125 ECT SENSOR

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.












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 ECM terminals, such as the ground.


On Board Diagnosis Logic

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

- If DTC P0125 is displayed with P0116, first perform the trouble diagnosis for DTC P0116.







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

1.Turn ignition switch ON.
2.Select "DATA MONITOR" mode with CONSULT.
3.Check that "COOLAN TEMP/S" is above -4�C (25�F).









4.Start engine and run it for 65 minutes at idle speed.





5.Check 1st trip DTC.
6.If 1st trip DTC is detected, go to .

With GST

Follow the procedure "With CONSULT" above.


Diagnosis Procedure


1. CHECK GROUND CONNECTIONS

1.Turn ignition switch OFF.





2.Loosen and retighten ground screws on the body.
For California.
-White arrow indicates : Vehicle front
-Body ground (1)
OK or NG
OK- GO TO 2.
NG- Repair or replace ground connections.

2. CHECK ENGINE COOLANT TEMPERATURE SENSOR

.
OK or NG
OK- GO TO 3.
NG- Replace engine coolant temperature sensor. Component.

3. CHECK THERMOSTAT OPERATION

When the engine is cold [lower than 70�C (158�F)] condition, grasp lower radiator hose and confirm the engine coolant does not flow.
OK or NG
OK- GO TO 4.
NG- Repair or replace thermostat. Removal And Installation.

4. CHECK INTERMITTENT INCIDENT

Refer to Initial Inspection and Diagnostic Overview
Engine Controls For California.
-INSPECTION END


Component Inspection


ENGINE COOLANT TEMPERATURE SENSOR






1.Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.










2.If NG, replace engine coolant temperature sensor.