Inspection Procedure

2009 Toyota FJ Cruiser RWDSECTION Inspection Procedure

HINT:

  • If any of DTCs P0115, P0116, P0117 or P0118 are set simultaneously with DTC P0125, the Engine Coolant Temperature (ECT) sensor may have an open or a short circuit. Troubleshoot those DTCs first.
  • Read freeze frame data using a Techstream. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0125) 
    1. Connect a Techstream to the DLC3.
    2. Turn the ignition switch ON.
    3. Turn the tester ON.
    4. Select the following menu items: 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 (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 )

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.