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 the troubleshooting of 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 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. Are there any other codes (besides DTC P0125) being out put ? 
   1. Read the DTCs using the hand-held tester or the OBD II scan tool.

   RESULT: 

   DTC OUTPUT DISPLAY
   
   

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

   HINT:

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

   1. B : Go to relevant DTC chart (see  DIAGNOSTIC TROUBLE CODE CHART  ).  
   2. A : Go to next step. 
2. Inspect thermostat (see  INSPECTION  ).  

   CHECK: 

   Check the valve opening temperature of the thermostat.

   HINT:

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

   1. NG : Replace (see  REMOVAL  ).  
   2. OK : Go to next step. 
3. Check cooling system. 

   CHECK: 

   Check that there is a defect in the cooling system which causes overcool, such as abnormal radiator fan operation or modified cooling system.

   1. NG : Repair or replace cooling system. 
   2. OK : Replace ECT sensor.