A/C System Performance Inspection

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

Confirm that vehicle and environmental conditions are as follows.
- Vehicle is not exposed to direct sun.
- Ambient temperature is within 15 - 35 °C (59 - 95 °F).
Make sure that high pressure valve (1) and low pressure valve (2) of manifold gauge set (3) are firmly closed.
Connect high pressure charging hose (4) to high pressure service valve (5), and connect low pressure charging hose (6) to low pressure service valve (7).
Bleed the air in charging hoses (4), (6) by loosening their respective nuts on manifold gauge set (3), utilizing the refrigerant pressure. When a hissing sound is heard, immediately tighten nut.

Fig 1: Connecting Charging Hoses To A/C System
Courtesy of SUZUKI OF AMERICA CORP.
Warm up engine to normal operating temperature (engine coolant temperature at 80 - 90 °C (176 - 194 °F)) and keep it at specified idle speed. (Radiator cooling fan should not be working when checking temperature.)
Set A/C switch to "ON" position, blower speed selector at maximum speed position, temperature selector at maximum cool position, air flow selector at "FACE" position and air intake selector at "RECIRCULATION" mode. (Confirm that A/C compressor and condenser cooling fan are working.)
Keep all windows, doors and engine food open.

Performance diagnosis condition

Ambient temperature: 15 - 35 °C (59 - 95 °F)

Engine rpm: Keep to 1,500 rpm.

Blower speed selector: Maximum speed position

Temperature selector: Maximum cool position

Air flow selector: "Face" position

Vehicle doors: All open

Air intake selector: "RECIRCULATION" mode
With dry bulb thermometer (1) inserted into center ventilation louver and another one set near recirculation air inlet, read temperature difference.

Fig 2: Setting A/C System For Testing
Courtesy of SUZUKI OF AMERICA CORP.
Check for each pressure of low side and high side if it is within shaded range of graph.
If each gauge reading is out of specified pressure, correct defective part referring to the table.

NOTE: Pressure registered on gauge varies with ambient temperature. Therefore, use the graphs when determining if pressures are normal or not.

Low side and high side pressure example, Gauges should read as follows when ambient temperature is 30 °C (86 °F)

Pressure on high pressure gauge: 1400 - 1750 kPa (14.0 - 17.5 kg/cm² , 199.1 - 248.9 psi)

Pressure on low pressure gauge: 230 - 350 kPa (2.3 - 3.5 kg/cm² , 32.7 - 49.8 psi)

Fig 3: Temperature/Pressure Graph
Courtesy of SUZUKI OF AMERICA CORP.

Fig 4: A/C System Performance Inspection High Pressure Gauge Chart (1 Of 2)
Courtesy of SUZUKI OF AMERICA CORP.

Fig 5: A/C System Performance Inspection Low Pressure Gauge Chart (2 Of 2)
Courtesy of SUZUKI OF AMERICA CORP.
Check for crossing point of center ventilation louver air temperature and recirculation air inlet temperature if it is within shaded range of graph.
For example, if inlet temperature is 25 °C (75 °F) and center ventilation louver temperature is 8 °C (46 °F), their crossing point is within acceptable range as shown in graph.

If crossing point is out of acceptable range, diagnose trouble referring to the following table.

Fig 6: Inlet/Outlet Temperature Chart
Courtesy of SUZUKI OF AMERICA CORP.

Fig 7: Crossing Point Of Center Ventilation Louver Air Temperature And Recirculation Air Inlet Temperature Diagnosis Chart

Courtesy of SUZUKI OF AMERICA CORP.

NOTE: If ambient temperature is approximately 30 °C (86 °F), it is possible to diagnose A/C system in detail referring to the following tables.

Fig 8: Manifold Pressure Chart (1 Of 2)

Courtesy of SUZUKI OF AMERICA CORP.

Fig 9: Manifold Pressure Chart (2 Of 2)

Courtesy of SUZUKI OF AMERICA CORP.