Diagnostic Procedure

DTC P0125 DIAGNOSTIC PROCEDURE

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED

Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (Engine cooling system related) been recorded?

Yes

Go to the next step.

Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

Check for related Service Bulletins and/or online repair information availability.
Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY CURRENT INPUT SIGNAL STATUS IS CONCERN INTERMITTENT OR CONSTANT

Start engine.
Warm up engine completely.
Access ECT PID using the WDS or equivalent.
Is ECT PID above 60°C {140°F} ?

Yes

Intermittent concern exists. Go to INTERMITTENT CONCERNS TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING ).

Go to the next step.

INSPECT ECT SENSOR CONNECTOR FOR POOR CONNECTION

Turn the ignition switch off.
Disconnect ECT sensor connector.
Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 8.

Go to the next step.

INSPECT ECT SENSOR

Inspect ECT sensor.
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION ).
Is it normal?

Yes

Go to the next step.

Replace ECT sensor, then go to Step 8.

INSPECT ENGINE COOLANT SYSTEM

Inspect the following items.
- Cooling system cap
- Radiator
- Thermostat
- Water pump
- Cooling fan
Are they normal?

Yes

Go to the next step.

Repair or replace necessary part, then go to Step 8.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

Disconnect PCM connector.
Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
Is there any malfunction?

Yes

Repair or replace the terminal, then go to the next step.

Go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0125 COMPLETED

Make sure to reconnect all disconnected connectors.
Clear the DTC from the PCM memory using the WDS or equivalent.
Turn ignition switch to ON (Engine off).
Access ECT PID using the WDS or equivalent.
Wait until ECT PID below 8°C {46°F} ⁽¹⁾ , 19.4°C {66.9°F} ⁽²⁾ .
Start engine and warm it up completely.
Is PENDING CODE for this DTC present?

Yes

Replace PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

Perform the "After Repair Procedure".
(See AFTER REPAIR PROCEDURE ).
Is any DTC present?

Yes

Go to the applicable DTC inspection.
(See DTC TABLE ).

Troubleshooting completed.

⁽¹⁾	California emission regulation applicable model

⁽²⁾	Except for California emission regulation applicable model