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On-Vehicle Inspection

  1. Inspect Refrigerant Volume 

    Observe the sight glass on the liquid tube.

    Fig 1: Locating Sight Glass
    G01025174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    Test conditions:

    • Running engine at 1,500 rpm
    • Blower speed control switch at "HI" position
    • A/C switch ON
    • Temperature control dial at "COOL" position
    • Fully open the doors
      Fig 2: Displaying Symptom & Remedy For Refrigerant Volume
      G01025175Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  2. Inspect Refrigerant Pressure With Manifold Gauge Set 

    This is a method in which the trouble is located by using a manifold gauge set. Read the manifold gauge pressure when the these conditions are established.

    Test conditions:

    • Temperature at the air inlet with the switch set at RECURC is 30 - 35 °C (86 - 95 °F)
    • Engine running at 1500 rpm
    • Blower speed control switch at "HI" position
    • Temperature control dial at "COOL" position
      NOTE: It should be noted that the gauge indications may vary slightly due to ambient temperature conditions.

    1. Normally functioning refrigeration system.
      1. Gauge reading: 
        1. Low pressure side: 
        2. 0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm 2  ) 
        3. High pressure side: 
        4. 1.37 - 1.57 MPa (14 - 16 kgf/cm 2  ) 
      Fig 3: Displaying Manifold Gauges Functioning Normally
      G01025176Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Moisture present in refrigeration system.
      Fig 4: Displaying Manifold Gauges With Moisture Present
      G01025177Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 5: Displaying Resolution For Moisture In Refrigeration System
      G01025178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Insufficient cooling.
      Fig 6: Displaying Manifold Gauges With Insufficient Cooling
      G01025179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 7: Displaying Resolution For Insufficient Cooling
      G01025180Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Poor circulation of refrigerant.
      Fig 8: Displaying Manifold Gauges With Poor Circulation Of Refrigerant
      G01025181Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 9: Displaying Resolution For Poor Circulation Of Refrigerant
      G01025182Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Refrigerant does not circulate.
      Fig 10: Displaying Manifold Gauges With No Circulation Of Refrigerant
      G01025183Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 11: Displaying Resolution For No Circulation Of Refrigerant
      G01025184Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Refrigerant overcharged or insufficient cooling of condenser.
      Fig 12: Displaying Manifold Gauges With Refrigerant Overcharged
      G01025185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 13: Displaying Resolution For Refrigerant Overcharged
      G01025186Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Air present in refrigeration system.
      Fig 14: Displaying Manifold Gauges With Air Present In Refrigerant System
      G01025187Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 15: Displaying Resolution For Air Present In Refrigerant System
      G01025188Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    8. Expansion valve improperly installed.
      Fig 16: Displaying Manifold Gauges With Improperly Installed Expansion Valve
      G01025189Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 17: Displaying Resolution For Improperly Installed Expansion Valve
      G01025190Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    9. Defective compressor.
      Fig 18: Displaying Manifold Gauges With Defective Compressor
      G01025191Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 19: Displaying Resolution For Defective Compressor
      G01025192Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Inspect Idle-Up Speed 
    1. Warm up engine.
    2. Inspect idle-up speed when the these conditions are establishe:
      • Warm up engine
      • Blower speed control switch at "HI" position
      • A/C switch ON
      • Temperature control dial at "COOL" position
      Fig 20: Displaying Magnetic Clutch Condition & Idle-Up Speed
      G01025193Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      If idle speed is not as specified, check idle control system.

  4. Inspect For Leakage Of Refrigerant 
    1. Perform these conditions:
      • Stop engine.
      • Secure good ventilation (If not, the gas leak detector may react to volatile gases which are not refrigerant, such as evaporated gasoline and exhaust gas.)
      • Repeat the test 2 or 3 times.
      • Make sure that there is some refrigerant remaining in the refrigeration system.

        When compressor is OFF: approx. 392 - 588 kPa (4-6 kgf/ cm2 , 57 - 85 psi)

    2. Bring the gas leak detector close to the drain hose before performing the test.
      NOTE:
      • After the blower motor stops, leave the cooling unit for at least 15 minutes.
      • Expose the gas leak detector sensor that is under the drain hose.
      • When bringing the gas leak detector close to the drain hose, make sure that the gas leak detector does not react to the volatile gases. If such reaction is unavoidable, the vehicle must be lifted up.
    3. If gas leak is not detected on the drain hose, remove the blower resistor from the cooling unit. Then insert the gas leak detector sensor into the unit and perform the test.
    4. Disconnect the connector and leave the pressure switch for approx. 20 minutes. Then bring the gas leak detector close to the pressure switch and perform the test.
    5. Bring the gas leak detector close to the refrigerant lines and perform the test.
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