Inspection Procedure

HINT:

• If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, 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, as well as other data from the time when a malfunction occurred.

1. Are there any other codes (besides DTC P0125) being output? 

   PREPARATION: 

   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON and push the hand-held tester main switch ON.
   3. When using hand-held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DTC INFO/CURRENT CODES.

   CHECK: 

   Read the DTCs using the hand-held tester.

   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 the troubleshooting for those DTCs first.

   1. B: Go to relevant  DIAGNOSTIC TROUBLE CODE CHART  
   2. A: Go to next step 
2. INSPECT THERMOSTAT 

   CHECK: 

   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  REMOVAL  ). 
   2. OK: Go to next step 
3. Check cooling system. 

   CHECK: 

   Check that there is detect 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.