AIR CONDITIONING SYSTEM Recirculated/Fresh Air Modes Switch without User Input

DESCRIPTION

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

Symptom Factor

  • Fresh/recirculation mode changes without permission.

  • Fresh/recirculation mode light blinks.

  • Automatic function set to ON in the customize setting

  • Change in fresh air temperature

  • Refrigerant pressure drop

  • Pressure sensor circuit

  • High engine coolant temperature

  • Smog ventilation sensor false opinion on Infringement

PROCEDURE


  1. CHECK FOR DTC (AIR CONDITIONING SYSTEM: B1423, B14B8)


    1. Clear the DTC.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    2. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      OK
      DTC B1423 and B14B8 are not output.
      Result
      Result Proceed to
      OK A
      NG (B1423 is output) B
      NG (B14B8 is output) C

    B

    GO TO DTC B1423 Click here

    C

    GO TO DTC B14B8 Click here

    A

  2. CHECK CUSTOMIZE SETTING


    1. Use the following customize setting methods to confirm that the automatically fresh/recirculation mode is "ON". If the setting is on, select the setting to "OFF".

      Click here


      • Check setting using Techstream

      • Check setting by multi-display

      OK
      Customize setting is "OFF".
      Result
      Proceed to
      OK
      NG

    NG

    CHANGE CUSTOMIZE SETTING IS ON

    OK

  3. READ VALUE USING GTS (EMISSION GAS SENSOR)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Allow exhaust gas (HC, CO) to travel to the sensing portion of the smog ventilation sensor.

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

    6. 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
      Emission Gas Sensor Emission gas (HC, CO)

      Min.: 0

      Max.: 255

      		 Smog ventilation sensor value increases as gas amount increases Smog ventilation sensor malfunction

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Emission Gas Sensor
      OK
      The display is as specified in the normal condition column.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

  4. INSPECT SMOG VENTILATION SENSOR


    1. Remove the smog ventilation sensor.

      Click here

    2. Inspect the smog ventilation sensor.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SMOG VENTILATION SENSOR Click here

    OK

  5. READ VALUE USING GTS (AMBIENT TEMP SENSOR)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    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 system 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

  6. READ VALUE USING GTS (COOLANT TEMPERATURE)


    1. Connect the GTS to the DLC3.

    2. Turn the power 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

  7. CHECK REFRIGERANT PRESSURE


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    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

      Max.: 3294.3 kPaG

      		 Actual refrigerant pressure displayed

      • Refrigerant line (gas leak etc.)

      • Air conditioner pressure sensor system 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