Your Vehicle: 2009 Nissan-Datsun Altima V6-3.5L (VQ35DE)
 
Vehicle » A L L Diagnostic Trouble Codes ( DTC ) » Testing and Inspection » P Code Charts » P0125  
 
 
  P0125  
 

P0125 ECT SENSOR

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.

  

  

DTC Logic

DTC DETECTION LOGIC

NOTE:

  • If DTC P0125 is displayed with P0116, first perform the trouble diagnosis for DTC P0116. Refer to See: P0116.
  • If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117, P0118. Refer to See: P0117.

  

DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds. >> GO TO 2.

2.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
With CONSULT-III

  1. Turn ignition switch ON.
  2. Select "DATA MONITOR" mode with CONSULT-III.
  3. Check that "COOLAN TEMP/S" is above 10C (50F) . With GST

Follow the procedure "With CONSULT-III" above.
Is the temperature above 10C (50F) ?
YES >> Inspection END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III

  1. Start engine and run it for 65 minutes at idle speed. If "COOLAN TEMP/S" increases to more than 10C (50F) within 65 minutes, stop engine because the test result will be OK.

CAUTION:
Never overheat engine.

  1. Check 1st trip DTC. With GST

Follow the procedure "With CONSULT-III" above.
Is 1st trip DTC detected?
YES >> Diagnosis Procedure
NO >> Inspection END

Diagnosis Procedure
1.CHECK GROUND CONNECTION

  1. Turn ignition switch OFF.
  2. Check ground connection E9. Refer to Ground Inspection in See: Testing and Inspection\Initial Inspection and Diagnostic Overview\Service Information For Electrical Incident\Circuit Inspection. Is the Inspection result normal?

YES >> GO TO 2.
NO >> Repair or replace ground connection.
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.
3.CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70C (158F) ] condition, grasp lower radiator hose and confirm that the engine coolant does not flow.
Is the Inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace thermostat. Refer to See: Engine, Cooling and Exhaust\Cooling System\Coolant Outlet\Service and Repair.
4.CHECK INTERMITTENT INCIDENT
Refer to See: Testing and Inspection\Initial Inspection and Diagnostic Overview\Service Information For Electrical Incident\Intermittent Incident.
>> Inspection END

Component Inspection
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR

  1. Turn ignition switch OFF.
  2. Disconnect engine coolant temperature sensor harness connector.
  3. Remove engine coolant temperature sensor.

  

  1. Check resistance between engine coolant temperature sensor terminals as per the following.

  

Is the Inspection result normal?
YES >> Inspection END
NO >> Replace engine coolant temperature sensor.