AIR CONDITIONING SYSTEM(for Manual Air Conditioning System) Recirculated/Fresh Air Modes Switch without User Input

DESCRIPTION

If recirculation/fresh mode changes unintentionally and without permission, the following causes are possible.

Symptom Factor

  • Recirculation/fresh mode changes without permission

  • Recirculation/fresh mode light blinks

  • Change in ambient air temperature

  • Decrease in refrigerant pressure

  • Air conditioner pressure sensor circuit malfunction

  • Engine coolant temperature (high)

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List.

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


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Ambient Temp Sensor Thermistor assembly

      Min.: -23.30°C (-9.94°F)

      Max.: 65.95°C (150.71°F)

      		 Actual ambient temperature displayed

      Thermistor assembly circuit malfunction


      • When open circuit: -23.30°C (-9.94°F)

      • When short circuit: 65.95°C (150.71°F)

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Ambient Temp Sensor
      OK
      The value of the display does not change frequently.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO AMBIENT TEMPERATURE DISPLAY SYSTEM Click here

    OK

  2. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    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 for 2AR-FE: Click here
    GO TO COOLING SYSTEM for A25A-FKS: Click here

    OK

  3. CHECK REFRIGERANT PRESSURE


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List.

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


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Regulator Pressure Sensor Air conditioner pressure sensor

      Min.: -456.6 kPaG (gauge)

      Max.: 3294.3 kPaG (gauge)

      		 Actual refrigerant pressure displayed

      • Refrigerant line (gas leak etc.)

      • Air conditioner pressure sensor circuit malfunction

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Regulator Pressure Sensor

    6. Install a manifold gauge set.

    7. Read the manifold gauge pressure when the following conditions are met.


      1. Prepare the vehicle according to the table below.

        Measurement Condition:
        Item Condition
        Vehicle doors Fully open
        Temperature setting MAX COLD
        Blower speed HI
        A/C switch On
        Recirculation/fresh switch RECIRCULATION
        Interior temperature 25 to 35°C (77 to 95°F)
      Standard Pressure
      Low pressure side
      150 to 250 kPa (1.5 to 2.5 kgf/cm2, 22 to 36 psi)
      High pressure side
      1370 to 1570 kPa (14 to 16 kgf/cm2, 199 to 228 psi)

    8. Compare the values displayed in the Data List and on the manifold gauge.

      OK
      The values displayed in the Data List and on the manifold gauge match.
      Result
      Proceed to
      OK
      NG

    OK

    GO TO ON-VEHICLE INSPECTION (CHECK REFRIGERANT PRESSURE USING GAUGE) Click here

    NG

    REPLACE AIR CONDITIONER PRESSURE SENSOR Click here