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 hand-held tester or the OBD II scan tool. 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 hand-held tester or the OBD II scan tool to the DLC3.
   2. Turn the power switch ON (IG).
   3. Turn the hand-held tester or the OBD II scan tool ON.
   4. On the hand-held tester, select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   5. Read DTCs using the hand-held tester or the OBD II scan tool.

      Result: 

      DTC OUTPUT DESCRIPTION
      
      

      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.

   1. B: GO TO RELEVANT DTC CHART (See  DIAGNOSTIC TROUBLE CODE CHART   ) 
   2. A: GO TO NEXT STEP 
2. INSPECT THERMOSTAT (See  INSPECTION  ) 
   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.

   THERMOSTAT (1NZ-FXE)

   1. NG: REPLACE THERMOSTAT (See ) 
   2. OK: GO TO NEXT STEP 

   REPLACE ENGINE COOLANT TEMPERATURE SENSOR (See  INSPECTION  )