AIR CONDITIONING SYSTEM No Heating at All

DESCRIPTION

If warm air is not discharged (airflow volume control is normal), the following malfunctions are possible.

Symptom Factor

  • No heating at all (airflow volume control is normal)

  • Air outlet temperature does not increase (airflow volume control is normal)

  • Low engine coolant temperature

  • A/M damper and link operation (jamming)

  • Warm-up Control

  • Heater core closed waterway

  • Heater accessory assembly

PROCEDURE


  1. READ VALUE USING GTS (COOLANT TEMPERATURE)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Data List.

    5. Read the Data List according to the display on the GTS.


      Powertrain > Engine > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Coolant Temperature Engine coolant temperature Min.: -40°C (-40°F), Max.: 140°C (284°F) 75 to 100°C (167 to 212°F): After warming up

      This is the engine coolant temperature.

      Tech Tips


      • After warming up the engine, the engine coolant temperature will be 75 to 100°C (167 to 212°F).

      • After a long soak, the engine coolant temperature, intake air temperature and ambient air temperature will be approximately equal.

      • If the value is -40°C (-40°F), or higher than 135°C (275°F), the sensor circuit is open or shorted.

      • Check if the engine overheats if the value indicated is higher than 135°C (275°F).

      Powertrain > Engine > Data List
      Tester Display
      Coolant Temperature
      OK
      The value of the display does not change frequently.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO COOLING SYSTEM Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS (AIR MIX SERVO TARG PULSE (D), AIR MIX SERVO TARG PULSE (P))


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    5. Check the operation by referring to the table below.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Restrict Condition
      Air Mix Servo Targ Pulse(D)

        for LHD:

      • No. 2 air conditioning radiator damper servo sub-assembly (driver side upper air mix) operation (for 4 Zone Type)

      • No. 4 air conditioning radiator damper servo sub-assembly (driver side upper air mix) operation (for Dual Type)


        for RHD:

      • No. 4 air conditioning radiator damper servo sub-assembly (driver side upper air mix) operation

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 254 to 326 pulses


        for RHD:

      • Operates between 186 to 258 pulses
      Air Mix Servo Targ Pulse(P)

        for LHD:

      • No. 4 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation


        for RHD:

      • No. 6 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation (for 4 Zone Type)

      • No. 2 air conditioning radiator damper servo sub-assembly (front passenger side upper air mix) operation (for Dual Type)

      Min.: 128

      Max.: 383

        for LHD:

      • Operates between 186 to 258 pulses


        for RHD:

      • Operates between 254 to 326 pulses

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(D)

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Air Mix Servo Targ Pulse(P)
      OK
      Damper servo motor is operated.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO DIAGNOSTIC TROUBLE CODE CHART (FOR SERVO MOTOR OF APPLICABLE ABNORMAL OPERATION) Click here

    OK

  3. INSPECT HEATER ACCESSORY ASSEMBLY


    1. Remove the heater accessory assembly.

      Click here

    2. Inspect the heater accessory assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY Click here

    NG

    GO TO HEATER WATER PUMP CIRCUIT Click here