Inspection Procedure

HINT:

• If DTCs P0115, P0116, P0117, P0118 and P0125 are output simultaneously, the engine coolant temperature sensor circuit may be open or short. Perform the troubleshooting of DTC P0115, P0117 or P0118 first.
• Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a 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 DTCS OUTPUT (IN ADDITION TO DTC P0125) 
   1. Connect the hand-held tester or to the DLC3.
   2. Turn the ignition switch to ON and turn the hand-held tester ON.
   3. Select the item: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   4. Read the DTCs.

      Result:

      OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125)
      
      

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

      HINT:

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

   1. B: GO TO 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: 

      Valve opening temperature is 80 to 84°C (176 to 183°F) 

      HINT:

      Also check that the valve is completely closed under opening temperature as above.

   1. NG: REPLACE THERMOSTAT (SEE  REPLACEMENT  ) 
   2. OK: Go to next step. 
3. CHECK COOLING SYSTEM 
   1. Check that there is a defect in the cooling system which causes overcool, such as abnormal radiator fan operation, modified cooling system and so on.
   1. NG: REPAIR OR REPLACE COOLING SYSTEM 
   2. OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR