LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2010 >> SC 430 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0010-P0340) >> SFI System >> DTC P0125: Insufficient Coolant Temperature for Closed Loop Fuel Control >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0125: Insufficient Coolant Temperature for Closed Loop Fuel Control: Procedure

  1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0125) 

    Result

    Result Proceed to
    P0125 A
    P0125 and other DTCs B

    HINT: 

    If any other codes besides P0125 are output, perform the troubleshooting for those codes first.

    B → See step   4 

    A: Go to next step 

  2. INSPECT THERMOSTAT 
    1. Check the valve opening temperature of the thermostat.

      Standard

      Valve opening temperature is 80 to 84°C (176 to 183°F)

      HINT: 

      Also check that the valve is completely closed below the opening temperature shown above.

    NG → See step   5 

    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 a modified cooling system.

    NG → REPAIR OR REPLACE COOLING SYSTEM 

    OK → See step   6 

  4. GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART 
  5. REPLACE THERMOSTAT. Refer to  REMOVAL 
  6. REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to  REMOVAL