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




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 5 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 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".

OR




With Generic Scan Tool
1. Turn ignition switch "ON".
2. Select "MODE 1" with GST.
3. Check that engine coolant temperature 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 engine coolant temperature increases to more than 10°C (50°F) within 65 minutes, stop engine because the test result will be OK.
5. Select "MODE 7" with GST.
6. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

OR




Without Scan Tools
1. Turn ignition switch "ON".
2. Check that voltage between ECM terminal (51) and ground is less than 3.8V.
If it is less than 3.8V, the test result will be OK.
If it is over 3.8V go to following step.
3. Start engine and run it for 65 minutes at idle speed. Then measure voltage between ECM terminal (51) and engine ground.
If the voltage decreases to less than 3.8V within 65 minutes, stop engine because the test result will be OK.
4. Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
5. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
6. It 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".







WIRING DIAGRAM




DIAGNOSTIC PROCEDURE










COMPONENT INSPECTION
Engine coolant temperature sensor
Check resistance.
If NG, replace engine coolant temperature sensor.