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

   Result: 

   DTC OUTPUT RESULT TABLE
   
   

   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.

   B: GO TO RELEVANT DTC CHART (See  DIAGNOSTIC TROUBLE CODE CHART  ) 

   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.

   NG: REPLACE THERMOSTAT (See step 6 on THERMOSTAT (2AZ-FE) (FROM JULY, 2003)  ) 

   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. 

   NG: REPAIR OR REPLACE COOLING SYSTEM 

   OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR