DSD Information System
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating / Air Conditioning System (Except HV, W/ Auto A/C) - Circuit Tests & Symptom Tests >> AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System) >> Recirculated/Fresh Air Modes do not Switch [11/2023 - ] >> Procedure

Recirculated/Fresh Air Modes do not Switch [11/2023 - ]: Procedure

  1. CHECK NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY 
    1. Check that the No. 1 blower damper servo sub-assembly is installed correctly.

      OK

      No. 1 blower damper servo sub-assembly is installed correctly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REINSTALL NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY. Refer to  REASSEMBLY [12/2019 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK FOR DTC 
    1. Check for DTCs.

      Body Electrical > Air Conditioner > Trouble Codes 

      Result

      Result Proceed to
      B143A-87 and B143B-7F are not output A
      B143A-87 is output B
      B143B-7F is output C

    Result: 

    GO TO DTC B143A-87. Refer to  DTC B143A-87: Lost Communication with Air Inlet Damper Control Servo Motor LIN Missing Message [11/2023 - ] 

    Result: 

    GO TO DTC B143B-7F. Refer to  DTC B143B-7F: Air Inlet Damper Control Servo Motor Actuator Stuck Off [11/2023 - ] 

    Result: 

    See step  3

  3. READ VALUE USING GTS (COOLANT TEMPERATURE) 
    1. 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.

      HINT: 

      • 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

    Result: 

    OK 

    REPLACE AIR CONDITIONER UNIT ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

    Result: 

    NG 

    GO TO COOLING SYSTEM. Refer to  ON-VEHICLE INSPECTION [10/2022 - ]