P0125

Reference Data:

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.

ON BOARD DIAGNOSIS LOGIC:

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

CAUTION: Be careful not to overheat engine.

NOTE:
- If both DTC P0115 (0103) and P0125 (0908) are displayed, 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-II.
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" below.

OR

With Generic Scan Tools
1. Start engine and run it for 65 minutes at idle speed.
2. Select "MODE 7" with GST.
If "COOLAN TEMP/S" increases to more than 10°C (50°F) within 65 minutes, stop engine because the test result will be OK.
3. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.

OR




Without Scan Tools
1. Start engine and run it for 65 minutes at idle speed.
2. Turn ignition switch "OFF", wait at least 5 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" below.
If voltage between ECM terminal (51) and ground decreases to less than 3.8V within 65 minutes, stop engine because the test result will be OK.

EC-ECTS-01:

EC-ECTS-01 - Connector View:

WIRING DIAGRAM

Diagnostic Procedure:

DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION







Engine coolant temperature sensor
Check resistance as shown in the figure.

Reference Data:

If NG, replace engine coolant temperature sensor.