Inspection Procedure

HINT:

• If any of DTC P0115, P0117, P0118 or P0125 are set simultaneously with DTC P0116, the engine coolant temperature sensor may have an open or a short circuit. Troubleshoot those DTCs first.
• Read freeze frame data using 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 P0166) 
   1. Connect Techstream to the DLC3.
   2. Turn the ignition switch on (IG).
   3. Turn the tester on.
   4. Select the following menu items: Powertrain/Engine and ECT/Trouble Code.
   5. Read the DTC.

   Result 

   RESULT TABLE
   
   

   Display (DTC output)	Proceed to
   P0116	A
   P0116 and other DTCs	B

   HINT:

   If any DTCs other than P0116 are output, troubleshoot those DTCs first.

   B:  GO TO DTC TABLE

   A: Go to next step 

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

      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.

   3. Reinstall the thermostat (See INSTALLATION ).

   NG: REPLACE THERMOSTAT  (See REMOVAL )

   OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR  (See REMOVAL )