Inspection Procedure 15: Overheating


COMMENT ON TROUBLE SYMPTOM



PROBABLE CAUSES



DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q. Diagnosis code set?
Inspection chart for diagnosis code (Refer to ).
Go to Step 2.

STEP 2. Check cooling fan.

  • Check cooling fan (Refer to GROUP 14 - Radiator Fan - Inspection ).

Q. Is the check result normal?
Go to Step 3.
Replace the cooling fan.

STEP 3. Check engine coolant
note If engine coolant level falls too early, check for leaky spots, and repair if necessary.

  • Check engine coolant (Refer to GROUP 14 - On-vehicle Service ).

Q. Is the check result normal?
Go to Step 4.
Replace or add engine coolant.

STEP 4. M.U.T.-III data list

  • Item 06: Engine coolant temperature sensor
OK:
    Engine cold state: At ambient temperature (atmospheric temperature) or equivalent.
    Engine hot state: At 80 - 120°C

Q. Is the check result normal?
Go to Step 5.
Check engine coolant temperature sensor system (Refer to Code No. P0117: Engine Coolant Temperature Sensor Circuit Low Input , Code No. P0118: Engine Coolant Temperature sensor circuit High Input ).

STEP 5. Check thermostat.

  • Check thermostat (Refer to GROUP 14 - Thermostat ).

Q. Is the check result normal?
Go to Step 6.
Replace the thermostat.

STEP 6. Check water pump.

  • Check water pump.

Q. Is the check result normal?
Replace the radiator.
Replace the water pump.