On-Vehicle Inspection

WARNING: This page is about a different car, the 2002 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

Inspect refrigerant volume :
Observe the sight glass on the liquid tube.

Fig 1: Locating Refrigerant Site Glass
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Understanding Conditions Indicated By Site Glass Readings
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Test conditions
- MAX. switch ON.
- Blower speed control set at "HI".
- Temperature control set at "MAX. COOL".
- Running engine at 1,500 rpm.
- Fully open the doors.
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 RECIRC is 30 - 35 °C (86 - 95 °F)
- Engine running at 1500 rpm
- Blower speed control switch at "HI" position
- Temperature control dial on "COOL" position
1. Normally functioning refrigeration system.
  
  Fig 3: Manifold Gauge Reading Normal Conditions
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Gauge reading
  1. Low pressure side: 0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm2.
  2. High pressure side: 1.37 - 1.57 MPa (14 - 16 kgf/cm2.
2. Moisture present in refrigeration system.
  
  Fig 4: Manifold Gauge Reading Moisture Present In System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 5: Diagnosis Chart Symptoms Of Moisture In System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Insufficient cooling
  
  Fig 6: Manifold Gauge Reading Insufficient Cooling
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 7: Diagnosis Chart Insufficient Cooling Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Poor circulation of refrigerant
  
  Fig 8: Manifold Gauge Reading Poor Refrigerant Circulation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 9: Diagnosis Chart Poor Circulation Of Refrigerant Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Refrigerant does not circulate
  
  Fig 10: Manifold Gauge Reading No Refrigerant Circulation
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 11: Diagnosis Chart No Refrigerant Circulation Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Refrigerant overcharged or insufficient cooling of condenser
  
  Fig 12: Manifold Gauge Reading Refrigerant Overcharged Or Condenser Insufficiently Cooled
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 13: Diagnosis Chart Refrigerant Overcharged Or Condenser Insufficiently Cooled Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
7. Air present in refrigeration system
  
  Fig 14: Manifold Gauge Reading Air Present In Refrigeration System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 15: Diagnosis Chart Air Present In Refrigeration System Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
8. Expansion valve operating improperly
  
  Fig 16: Manifold Gauge Reading Improper Operation Of Expansion Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 17: Diagnosis Chart Improper Operation Of Expansion Valve Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
9. Defective compression compressor
  
  Fig 18: Manifold Gauge Reading Defective Compressor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 19: Diagnosis Chart Defective Compressor Symptoms
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect for leakage of refrigerant :
1. Perform in these conditions:
  - Stop engine.
  - Secure good ventilation (If the gas leak detector may not 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: approximately 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.
  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 approximately 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.
Inspect idle-up speed :
1. Activate inspection mode. See INSPECTION MODE .
2. Inspect idle-up speed when the these conditions are established.
  Test conditions
  - Idle speed set correctly.
  - Steering wheel straight ahead
  - Blower speed control dial at HI
  - A/C switch ON
    
    Fig 21: Idle Speed Specifications
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    If idle speed is not as specified, check the engine ECU and throttle body.