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Home >> Lexus >> 2008 >> LS 600hL >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTC P0120 - P0453 >> 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 intelligent tester or Techstream to the DLC3
    2. Turn the power switch ON (IG)
    3. Turn the tester ON.
    4. Enter the following menus:
      1. Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
      2. Techstream - Select: Powertrain / Engine and ECT / Trouble Codes.
    5. Read DTCs.

      Result 

      RESULT REFERENCE

      Display (DTC Output) Proceed to
      P0125 A
      P0125 and other DTCs 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 modifications.

    NG: REPAIR OR REPLACE COOLING SYSTEM 

    OK: REPLACE ENGINE COOLANT TEMPERATURE SENSOR  (See REMOVAL )