Nissan Sentra B18 (2020-2025) Service Manual: P0125 Ect Sensor

Dtc Description

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connectors (High resistance in the engine coolant temperature sensor circuit)

• Engine coolant temperature sensor

• Thermostat

FAIL-SAFE

Not applicable

Confirmation Procedure

1. CHECK DTC PRIORITY

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

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

   Is applicable DTC detected?

   YES >>

   Perform diagnosis of applicable.

   • DTC P0116: Refer to DTC Description.

   • DTC P0117 or P0118: Refer to DTC Description.

   NO >>

   GO TO 2.

2. PRECONDITIONING

   If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

   >>

   GO TO 3.

3. CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION

   With CONSULT

   1. Turn ignition switch ON.

   2. Select “DATA MONITOR” mode of “ENGINE” using CONSULT.

   3. Check that “COOLANT TEMP/S” is above −4°C (25°F).

   With GST

   Follow the procedure “With CONSULT” above.

   Is it above −4°C (25°F)?

   YES-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   YES-2 >>

   Confirmation after repair: INSPECTION END

   NO >>

   GO TO 4.

4. PERFORM DTC CONFIRMATION PROCEDURE

   With CONSULT

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

   2. Check 1st tip DTC.

   If “COOLANT TEMP/S” indication increases to more than −4°C (25°F) within 65 minutes, stop engine because the test result will be OK.

   CAUTION:

   Be careful not to overheat engine.

   With GST

   Follow the procedure “With CONSULT” above.

   Is 1st trip DTC detected?

   YES >>

   Proceed to DTC Diagnosis Procedure.

   NO-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

1. CHECK DTC PRIORITY

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

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

   Is applicable DTC detected?

   YES >>

   Perform diagnosis of applicable.

   • DTC P0116: Refer to DTC Description.

   • DTC P0117 or P0118: Refer to DTC Description.

   NO >>

   GO TO 2.

2. CHECK ENGINE COOLANT TEMPERATURE SENSOR

   Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   GO TO 3.

   NO >>

   Replace engine coolant temperature sensor. Refer to Exploded View.

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.

   Is the inspection result normal?

   YES >>

   INSPECTION END

   NO >>

   Repair or replace thermostat. Refer to Removal and Installation.

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