LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2007 >> FJ Cruiser 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> SFI System >> DTC P0125: Insufficient Coolant Temperature for Closed Loop Fuel Control >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

HINT:

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125) 
    1. Connect an intelligent tester to the DLC3.
    2. Turn the ignition switch ON.
    3. Turn the tester ON.
    4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
    5. Read DTCs.

      Result 

      DTC RESULT DESCRIPTION

      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  DIAGNOSTIC TROUBLE CODE TABLE  

    A: Go TO NEXT STEP 

  2. INSPECT WATER INLET WITH THERMOSTAT (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.

    3. Reinstall the water inlet with thermostat (See INSTALLATION ).

    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  )