On-Vehicle Inspection: Notes

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT REFRIGERANT VOLUME
1. Check the sight glass on the liquid tube.
  Test conditions:
- Engine is running at 1,500 RPM
- Single A/C:
  Blower speed control switch at "HI" position
- Dual A/C:
  Front blower switch at "HI" position
  
  Rear blower switch at "HI" position
- A/C switch ON
- Single A/C:
  Temperature control switch at "MAX. COOL" position
- Dual A/C:
  Rear temperature control switch at "MAX.COOL" position
  
  Front driver side temperature control switch at "MAX.COOL" position
  
  Front passenger side temperature control switch at "MAX.COOL" position
- Fully open the doors
  
  Fig 1: Locating Sight Glass
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 2: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET
1. This is a method in which trouble is located by using manifold gauge set. Read the manifold gauge pressure when these conditions are established.
  Test conditions:
- Temperature at the air inlet with the switch set at RECIRC is 30 to 35°C (86 to 95°F)
- Engine is running at 2,000 RPM
- Blower speed control switch is at "HI"
- Temperature control dial is at "COOL"
HINT:

It should be noted that the gauge indications may vary slightly due to ambient temperature conditions.
1. Normally functioning refrigeration system
  Gauge reading:
  
  Low pressure side:
  
  0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm ² )
  
  High pressure side:
  
  1.37 to 1.57 MPa (14 to 16 kgf/cm ² )
  
  Fig 3: Identifying Manifold Gauge Set
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Moisture present in refrigeration system
  
  Fig 4: Identifying Manifold Gauge Set - Moisture Present In Refrigeration System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 5: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Insufficient cooling
  
  Fig 6: Identifying Manifold Gauge Set - Insufficient Cooling
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 7: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Poor circulation of refrigerant
  
  Fig 8: Identifying Manifold Gauge Set - Poor Circulation Of Refrigerant
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 9: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Refrigerant does not circulate
  
  Fig 10: Identifying Manifold Gauge Set - Refrigerant Does Not Circulate
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 11: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Refrigerant is overcharged or cooling effectiveness of condenser is insufficient
  
  Fig 12: Identifying Manifold Gauge Set - Refrigerant Is Overcharged Or Cooling Effectiveness Of Condenser Is Insufficient
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 13: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
7. Air present in refrigeration system
  
  Fig 14: Identifying Manifold Gauge Set - Air Present In Refrigeration System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 15: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
8. Expansion valve malfunction
  
  Fig 16: Identifying Manifold Gauge Set - Expansion Valve Malfunction
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 17: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
9. Defective compression compressor
  
  Fig 18: Identifying Manifold Gauge Set - Defective Compression Compressor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 19: Diagnostic Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002