Inspection Procedure

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0128) 
   1. Connect the Techstream to the DLC3.
   2. Turn the ignition switch on.
   3. Turn the tester on.
   4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   5. Read DTCs.

      Result 

      RESULT REFERENCE TABLE
      
      

      Display (DTC Output)	Proceed to
      P0128	A
      P0128 and other DTCs	B

      HINT:

      If any DTCs other than P0128 are output, troubleshoot those DTCs first.

   B:  GO TO DTC TABLE 

   A: Go To Next Step 

2. CHECK COOLING SYSTEM 
   1. Check that there is no defect in the cooling system which causes overcool, such as abnormal radiator fan operation, modified cooling system and so on.

   NG: REPAIR OR REPLACE COOLING SYSTEM 

   OK: Go To Next Step 

3. INSPECT THERMOSTAT 
   1. Remove the thermostat (See REMOVAL ).
   2. Check the valve opening temperature of the thermostat (See INSPECTION ).

      Standard: 

      80° to 84°C (176° to 183°F) 

      HINT:

      In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.

   NG: REPLACE THERMOSTAT 

   OK: REPLACE ECM