P0125

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.




CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.




ON BOARD DIAGNOSIS LOGIC




DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

CAUTION: Be careful not to overheat engine.

NOTE:
- If DTC P0125 (0908) is displayed with P0115 (0103), first perform "TROUBLE DIAGNOSIS FOR DTC P0115".
- If "DIAGNOSTIC TROUBLE CODE 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. 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.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

With Generic Scan Tools
1. 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.
2. Select "MODE 7" with GST.
3. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR

Without Scan Tools
1. Start engine and run it for 65 minutes at idle speed. If voltage between ECM terminal (59) and ground decreases to less than 3.8 V within 65 minutes, stop engine because the test result will be OK.
2. Turn ignition switch "OFF", wait at least 10 seconds and then turn "ON".
3. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
4. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".







WIRING DIAGRAM




DIAGNOSTIC PROCEDURE











COMPONENT INSPECTION
Check resistance as shown in the figure.
If NG, replace engine coolant temperature sensor.