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Home >> Lexus >> 2008 >> IS F >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - SFI System Diagnostics (2 Of 4) >> DTC P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control >> Inspection Procedure
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Inspection Procedure

HINT

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG)
    3. Turn the Techstream ON.
    4. Enter the following menus. Powertrain / Engine / Trouble Codes.
    5. Read the DTCs.

      Result 

      RESULT CHART

      Result Proceed to
      DTC P0125 is output A
      DTC P0125 and other DTCs are output B

      HINT.

      If any DTCs other than P0125 are output, troubleshoot those DTCs first.

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

    A: Go to next step 

  2. INSPECT WATER INLET WITH THERMOSTAT 
    1. Remove the water inlet with 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

    NG: REPLACE WATER INLET WITH THERMOSTAT  (See REMOVAL )

    OK: Go to next step 

  3. CHECK COOLING SYSTEM 
    1. Check for defects in the cooling system that might cause the system to be too cold, such as abnormal radiator fan operation or any modifications.

    NG: REPAIR OR REPLACE COOLING SYSTEM 

    OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR  (See REMOVAL )