AIR CONDITIONING SYSTEM Front Window Fogging

DESCRIPTION

If the front glass frequently fogs up when the air conditioning system is operated, the following causes are possible.

Symptom Factor
Front glass frequently fogs

  • Compressor with motor assembly

  • Quantity of refrigerant gas lack

  • Cooler expansion valve (opened too far)

  • DEF servo motor malfunction

  • Damper and link operation (jamming)

PROCEDURE


  1. CHECK REFRIGERANT SHORTAGE


    1. Prepare the vehicle according to the table below.

      Measurement Condition:
      Item Condition
      A/C switch On
      Ambient temperature*2 0 to 49°C (32 to 120°F)
      Air conditioning inlet temperature*3 25 to 49°C (77 to 120°F)
      Setting temperature MAX COLD
      Blower damper position Recirculation
      Outlet damper position FACE
      Blower speed HI

      • *2: If the ambient temperature is not within the range shown, do not perform this check.

      • *3: The air inlet temperature can be judged correctly only if it is within an appropriate range of 25 to 79°C (77 to 174°F). Therefore, use the heater mode to adjust the temperature so that it falls within the appropriate range and then perform the check.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (READY).

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Air Conditioner / Utility / Refrigerant Gas Volume Check.


      Body Electrical > Air Conditioner > Utility
      Tester Display
      Refrigerant Gas Volume Check
      Result
      Result Amount of Refrigerant
      Refrigerant shortage Insufficient or leakage
      Refrigerant correct Correct
      Result
      Result Proceed to
      Insufficient or leakage A
      Correct B

    B

    CHARGE SYSTEM WITH REFRIGERANT for HFC-134a (R134a): Click here for HFO-1234yf (R1234yf): Click here

    A

  2. CHECK OPERATION


    1. When the MODE switch pushed, check that the air conditioning system changes DEF mode according to the switch operation.

      OK
      Air conditioning system changes DEF mode.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    GO TO DTC B1443 Click here