AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System) Weak Blower Output

DESCRIPTION

If the airflow from the front registers is weak regardless of the blower speed setting displayed on the air conditioning control panel (radio and display receiver assembly)*1 or air conditioning control assembly*2, the following factors may be the cause.

Symptom Factor

  • Airflow volume is constantly low

  • Airflow volume sometimes becomes low

  • Blower motor with fan sub-assembly malfunction

  • Clogged clean air filter

  • Clogged No. 1 evaporator sub-assembly or heater radiator unit sub-assembly fins

  • No. 1 cooler thermistor malfunction

  • ECO mode control of air conditioning system is enabled*3

  • Aspirator not connected properly

PROCEDURE


  1. CHECK AIR CONDITIONING SYSTEM


    1. Operate the blower switch with the following conditions met and check that the airflow volume changes.

      Blower Speed Condition
      LO → HI

      • Temperature setting: MAX COLD

      • Air outlet mode: FACE

      • A/C switch: Off
      OK
      Airflow volume increases.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO OTHER DIAGNOSIS PROCEDURE (Blower Motor Circuit) Click here

    OK

  2. CONFIRM MODEL

    Result
    Result Proceed to
    w/ ECO Switch A
    w/o ECO Switch B

    B

    GO TO STEP 4 Click here

    A

  3. CHECK ECO MODE CONTROL OPERATION


    1. Check that ECO mode control is disabled (ECO mode indicator is not illuminated).

    2. Operate the ECO switch assembly (electric parking brake switch assembly) and check that the ECO mode indicator illuminates and the blower speed is reduced.

      Tech Tips


      • When ECO mode control is operating, the air conditioning amplifier assembly controls the air conditioning system to enhance fuel efficiency. Therefore, explain to the customer that, when ECO mode control is operating, the blower speed will be reduced.

        Control Outline
        Blower Control When the air conditioning system is in AUTO mode, the blower speed will be reduced to a certain speed. Additionally, if warm-up control is operating, the blower speed will be further reduced.
        Air Inlet Control If the ambient temperature is a certain value or more, the air inlet mode will be changed to recirculation mode.

      • In some situations, ECO mode control may not operate even though it is enabled.

    3. Operate the ECO switch assembly (electric parking brake switch assembly) and check that the ECO mode indicator turns off and the blower speed returns to normal.

      OK
      When the ECO switch assembly (electric parking brake switch assembly) is operated, ECO mode control is enabled/disabled and the blower speed is controlled.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO ECO Switch Circuit Click here

    OK

  4. CHECK CLEAN AIR FILTER


    1. Visually check the clean air filter.

      Click here

      OK
      The clean air filter is not dirty or clogged.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE CLEAN AIR FILTER Click here

    OK

  5. CHECK NO. 1 COOLER THERMISTOR


    1. Check the installation condition of the No. 1 cooler thermistor.

      OK
      The No. 1 cooler thermistor is installed correctly.
      Result
      Proceed to
      OK
      NG

    NG

    INSTALL NO. 1 COOLER THERMISTOR Click here

    OK

  6. CHECK ASPIRATOR


    1. Check the installation condition of the aspirator.

      OK
      The aspirator is installed correctly.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEATER RADIATOR UNIT SUB-ASSEMBLY OR NO. 1 COOLER EVAPORATOR SUB-ASSEMBLY Click here

    NG

    INSTALL ASPIRATOR Click here