Inspection Procedure

HINT:

• If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, engine coolant temperature sensor circuit may be open or short. Perform troubleshooting on DTC P0115, P0117 or P0118 first.
• Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0125) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the power switch ON (IG).
   3. Turn the intelligent tester ON.
   4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   5. Read DTCs using the intelligent tester.

      Result 

      RESULT REFERENCE
      
      

      Display (DTC output)	Proceed to
      P0125	A
      P0125 and other DTCs	B

      HINT:

      If any other codes besides P0125 are output, perform troubleshooting for those DTCs first.

   B : GO TO RELEVANT DTC CHART 

   A : Go to Next Step 

2. INSPECT THERMOSTAT 
   1. Check the valve opening temperature of the thermostat.

      OK : Thermostat valve begins to open at temperature of 80 to 84°C (176 to 183°F) 

      HINT:

      Also check that the valve is completely closed below temperature shown above.

   NG : REPLACE THERMOSTAT 

   OK : REPLACE ENGINE COOLANT TEMPERATURE SENSOR