COMBUSTION TYPE POWER HEATER SYSTEM, Diagnostic DTC:012, 014, 015, 017

DTC Code DTC Name
012 Overheating
014 Difference Evaluation Overheating
015 Operating Block caused by Overheating
017 Hardware Overheating

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
012 The surface sensor or temperature control sensor detects a temperature of 125°C (257°F) or higher.

  • Heater assembly (surface sensor)

  • Heater assembly (temperature control sensor)

  • Engine coolant circuit
014 When the engine coolant temperature is 80°C (176°F) and the heater assembly is operating, the difference in temperatures detected by the surface sensor and temperature control sensor is 25°C (77°F) or higher.

  • Heater assembly (surface sensor)

  • Heater assembly (temperature control sensor)

  • Engine coolant circuit
015 The temperature control sensor detects overheating of the engine coolant, and the ECU stops the operation of the heater assembly (one or both of DTCs 012 and 014 are detected 10 times in a row).

  • Engine coolant circuit

  • Heater assembly
017 When neither DTC 012 nor 014 is detected, the temperature control sensor or surface sensor detects a temperature of 130°C (266°F) or more.

  • Heater assembly (surface sensor)

  • Heater assembly (temperature control sensor)

  • Engine coolant circuit

INSPECTION PROCEDURE

Tech Tips

Output of DTC 015 indicates that the heater assembly has been locked by the ECU and cannot be operated. Clear the DTCs by pressing the memory clear buttons on the DTC tester to unlock the ECU Click here.

PROCEDURE


  1. INSPECT FOR ENGINE COOLANT LEAK

    Note

    Before performing the inspection, turn the A/C switch off.


    1. A01IU3X

      Remove the radiator reservoir cap.

      CAUTION:

      To avoid the danger of being burned, do not remove the radiator reservoir cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator.

    2. Fill the radiator with coolant, and then attach a radiator cap tester.

    3. Warm up the engine.

    4. Pump the radiator cap tester to 118 kPa (1.2 kgf/cm2, 17 psi), and then check that the pressure does not drop.

      If the pressure drops, check the hoses, radiator and water pump for leakage.

      If there are no signs of external coolant leaks, check the heater core, cylinder block and head.

      OK
      The pressure does not drop.

    NG

    REPAIR ENGINE COOLANT LEAK

    OK

  2. INSPECT ENGINE COOLANT QUALITY

    Note

    Before performing the inspection, turn the A/C switch off.


    1. Remove the radiator reservoir cap.

      CAUTION:

      To avoid the danger of being burned, do not remove the radiator reservoir cap while the engine and radiator are still hot. Thermal expansion will cause hot engine coolant and steam to blow out from the radiator.

    2. Check for any excessive deposits of rust or scales around the radiator reservoir cap and radiator filler hole. The coolant should be free of oil.

      OK
      Coolant is normal.
      Result
      Result Proceed to
      OK A
      NG (for 1AD-FTV) B
      NG (for 2AD-FHV) C

    B

    REPLACE ENGINE COOLANT Click here

    C

    REPLACE ENGINE COOLANT Click here

    A

  3. INSPECT THERMOSTAT

    Tech Tips

    The valve opening temperature is inscribed on the thermostat.

    A01IRZPE03

    1. A01IPMUE01

      Immerse the thermostat in water, and then gradually heat the water.

    2. Check the valve opening temperature of the thermostat.

      Standard valve opening temperature
      80 to 84°C (176 to 183°F)
    3. A01IUE4E14

      Check the valve lift.

      Standard valve lift
      10 to 14 mm (0.394 to 0.551 in.) at 95°C (203°F)

    4. Check that the valve is fully closed when the thermostat is at a low temperature (below 77°C [171°F]).

      Result
      Result Proceed to
      The results are as specified A
      The results are not as specified (for 1AD-FTV) B
      The results are not as specified (for 2AD-FHV) C

    B

    REPLACE THERMOSTAT Click here

    C

    REPLACE THERMOSTAT Click here

    A

  4. INSPECT WATER PUMP ASSEMBLY


    1. A01INYR

      Turn the pulley and check that the water pump bearing moves smoothly and quietly.

    2. Make sure that there are no drops of coolant on the water pump housing.

      OK
      Water pump assembly is normal.
      Result
      Result Proceed to
      OK A
      NG (for 1AD-FTV) B
      NG (for 2AD-FHV) C

    B

    REPLACE WATER PUMP ASSEMBLY Click here

    C

    REPLACE WATER PUMP ASSEMBLY Click here

    A

    REPLACE HEATER ASSEMBLY Click here