Air Conditioning (A/C) System Performance Test
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Air Conditioning (A/C) System Performance Test
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This test measures the operating efficiency of the A/C system under the following conditions:
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The current ambient air temperature
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The current relative humidity
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The high side pressure of the A/C system
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The low side pressure of the A/C system
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The temperature of the air being discharged into the passenger compartment
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Test Description
The numbers below refer to the step numbers on the diagnostic table.
1
This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
2
This step measures the performance of the A/C system.
3
This step is to allow for vehicle variations as well as high ambient temperatures.
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Step
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Action
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Values
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Yes
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No
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Note
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The ambient air temperature must be at least 16°C (60°F) .
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Do not induce additional air flow across the front of the vehicle during the test.
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If you were sent here from a DTC diagnostic table, clear the DTC upon completion of this test.
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1
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1.
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Park the vehicle inside or in the shade.
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2.
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Open the windows in order to ventilate the interior of the vehicle.
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3.
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If the A/C system was operating, allow the A/C system to equalize for about 2 minutes.
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4.
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Turn OFF the ignition.
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5.
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Install the
J-43600
ACR 2000 Air Conditioning Service Center or
GE-48800
CoolTech A/C Recharge Machine
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6.
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Record the ambient air temperature and humidity.
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7.
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Record the low and high side STATIC pressure readings.
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Are both the low side and high side pressures within the specified value?
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More than 16°C (60°F) - 345 kPa (50 psi)
More than 24°C (75°F) - 483 kPa (70 psi)
More than 33°C (90°F) - 690 kPa (100 psi)
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Go to
Step 2
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Go to
Leak Testing
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2
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1.
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Note
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Record the relative humidity and the ambient air temperature at the time of the test.
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Close the vehicle doors and windows.
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2.
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Open the drivers door window 12.7-15.2 cm (5-6 in).
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3.
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Select the following HVAC control settings:
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The coldest temperature setting
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The maximum blower speed
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The instrument panel (I/P) outlet mode
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All I/P outlets are OPEN.
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4.
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Install thermometers in the left and right center panel air outlets.
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5.
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Apply the parking brake.
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6.
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Place the transaxle/transmission in one of the following positions:
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7.
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Start the engine and warm to operating temperature.
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8.
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Operate the A/C system for 5 minutes.
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9.
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Inspect A/C components for the following conditions:
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10.
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Record the following information:
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The panel outlet air temperatures
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11.
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Compare the low and high side pressures and the panel output temperatures to the A/C Performance Table below.
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Does all the data recorded fall within the specified ranges of the A/C Performance Table below?
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Go to
Step 5
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Go to
Step 3
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3
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If the pressures and temperatures recorded do not fall within the specified ranges:
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1.
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Continue to operate the A/C system for an additional 5 minutes.
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2.
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Record the pressures and temperatures again.
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3.
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Compare the low and high side pressures and the panel output temperature to the A/C Performance Table below.
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Does all the data recorded fall within the specified ranges of the A/C Performance Table below?
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Go to
Step 5
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Go to
Step 4
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4
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Perform the necessary repairs. Refer to
A/C Diagnostics Chart
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Is the action complete?
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Go to
Step 5
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5
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Operate the system in order to verify the test results.
Did you find the same results?
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System OK
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Go to
Symptoms - HVAC Systems - Automatic
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A/C Performance Table
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Ambient Temperature
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Relative Humidity
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Low Side Service Port Pressure
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High Side Service Port Pressure
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Maximum Left Center Discharge Air Temperature
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13-18°C (55-65°F)
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0-100%
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175-200 kPa (25-30 psi)
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500-850 kPa (70-125 psi)
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5°C (40°F)
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19-24°C (66-75°F)
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Less than 40%
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175-240 kPa (25-35 psi)
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690-1100 kPa (100-160 psi)
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5°C (40°F)
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Greater than 40%
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175-240 kPa (25-35 psi)
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690-1100 kPa (100-160 psi)
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7°C (45°F)
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25-29°C (76-85°F)
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Less than 35%
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175-240 kPa (25-35 psi)
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1000-1300 kPa (145-190 psi)
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10°C (50°F)
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35-60%
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175-240 kPa (25-35 psi)
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1000-1340 kPa (145-195 psi)
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10°C (50°F)
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Greater than 60%
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175-280 kPa (25-40 psi)
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1000-1370 kPa (145-200 psi)
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10°C (50°F)
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30-35°C (86-95°F)
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Less than 30%
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175-280 kPa (25-40 psi)
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1240-1590 kPa (180-230 psi)
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13°C (55°F)
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30-50%
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175-280 kPa (25-40 psi)
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1240-1620 kPa (180-235 psi)
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13°C (55°F)
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Greater than 50%
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175-280 kPa (25-40 psi)
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1240-1650 kPa (180-240 psi)
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13°C (55°F)
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36-41°C (96-105°F)
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Less than 20%
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240-320 kPa (35-45 psi)
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1500-1860 kPa (215-270 psi)
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15°C (60°F)
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20-40%
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240-320 kPa (35-45 psi)
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1500-1900 kPa (215-275 psi)
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15°C (60°F)
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Greater than 40%
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240-320 kPa (35-45 psi)
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1500-1900 kPa (215-275 psi)
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15°C (60°F)
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42-46°C (106-115°F)
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Less than 20%
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280-350 kPa (40-50 psi)
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1765-2100 kPa (255-305 psi)
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18°C (65°F)
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Greater than 20%
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280-350 kPa (40-50 psi)
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1765-2100 kPa (255-305 psi)
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18°C (65°F)
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47-49°C (116-120°F)
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Below 30%
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320-380 kPa (45-55 psi)
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2000-2240 kPa (290-325 psi)
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20°C (70°F)
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