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, P0118: ENGINE COOLANT TEMPERATURE CIRCUIT, ENGINE COOLANT TEMPERATURE CIRCUIT LOW/HIGH INPUT  first.
• Read freeze frame data using the hand-held tester or the OBDII scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

1. CHECK OTHER DTC OUTPUT (lN ADDITION TO DTC P0125) 
   1. Read the DTC using the hand-held tester or the OBD II scan tool.

      Result: 

      OTHER DTC OUTPUT (lN ADDITION TO DTC P0125)
      
      

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

      HINT:

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

   1. NG: REPLACE THERMOSTAT (See  THERMOSTAT (3MZ-FE)  ) 
   2. OK: Go to next step. 
3. CHECK COOLING SYSTEM 
   1. Check the cooling system for excessive cooling, such as abnormal radiator fan operation, modified cooling system and other defects.

      OK: There is no modification of cooling system. 

   1. NG: REPAIR OR REPLACE COOLING SYSTEM 
   2. OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR