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Test Description

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

This test measures the operating efficiency of the A/C system under the following conditions:

The numbers below refer to the step numbers on the diagnostic table.

  1. 1:  This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
  2. 2:  This step measures the performance of the A/C system.
  3. 3:  This step is to allow for vehicle variations as well as high (AATs).
Air Conditioning (A/C) System Performance Test

Step Action Values Yes No
IMPORTANT:
  • The ambient air temperature (AAT) must be at least 16° C (60° F).
  • Do not induce additional air flow across the front of the vehicle during the test.
  • If you were sent here from a DTC diagnostic table, clear the DTC upon completion of this test.
1 
  1. Park the vehicle inside or in the shade.
  2. Open the windows in order to ventilate the interior of the vehicle.
  3. If the A/C system was operating, allow the A/C system to equalize for about 2 minutes.
  4. Turn OFF the ignition.
  5. Install the J 43600  ACR 2000 Air Conditioning Service Center. See Special Tools and Equipment .
  6. Record the ambient air temperature (AAT) displayed on the J 43600  . See Special Tools and Equipment .
  7. Record readings of the low and high side STATIC pressures.
Are both the low and high side pressures within the specified value?		 Above 16° C (60° F) - 345 kPa (50 psi)
Above 24° C (75° F) - 483 kPa (70 psi)
Above 33° C (90° F) - 690 kPa (100 psi)		 Go to Step 2  Go to Leak Testing 
2 
    IMPORTANT: Record the relative humidity and the AAT AT THE TIME OF THE TEST.
  1. Close the vehicle doors and windows.
  2. Open the driver door window 12.7-15.2 cm (5-6 in).
  3. Select the following HVAC control setting:
    • The A/C is ON.
    • The coldest temperature setting
    • The maximum blower speed
    • Recirculation mode
    • The instrument panel (I/P) outlet mode
    • All I/P outlets are OPEN
  4. Install the temperature probes of the J 43600  in the left and right center panel air outlets. See Special Tools and Equipment .
  5. Apply the parking brake.
  6. Place the transmission in PARK.
  7. Start the engine.
  8. Operate the A/C system for 5 minutes.
  9. Inspect A/C components for the following conditions:
    • Abnormal frost areas
    • Unusual noises
    10. IMPORTANT: When performing this step it is necessary to press the RESET button on the J 43600  before pressing the PRINT button. See Special Tools and Equipment .
  10. Print the following information:
    • The panel outlet air temperatures
    • The low-side pressure
    • The high-side pressure
  11. Compare the low and high side pressures and the panel output temperatures to the A/C performance table below.
Does all the data recorded fall within the specified ranges of the A/C performance table?		 - Go to Step 8  Go to Step 3 
3  If the pressures and temperatures recorded do not fall within the specified ranges:
  1. Continue to operate the A/C system for an additional 5 minutes.
  2. Record the pressures and temperatures again.
  3. Compare the low and high side pressures and the panel output temperature to the A/C performance table.

Does all the data recorded fall within the specified ranges of the A/C performance table?		 - Go to Step 8  Go to Step 4 
4 Do the high and low side pressures fall within the specified ranges, but the panel outlet temperatures do not? - Go to Air Conditioning (A/C) Diagnostics - Pressure Zone A  Go to Step 5 
5 Is the low side pressure greater than the specified range, but the high side pressure is within or less than the specified range? - Go to Air Conditioning (A/C) Diagnostics - Pressure Zone B  Go to Step 6 
6 Are the low and high side pressures both greater than the specified ranges? - Go to Air Conditioning (A/C) Diagnostics - Pressure Zone C  Go to Step 7 
7 Is the high side pressure greater than the specified range, but the low side pressure is within or less than the specified range? - Go to Air Conditioning (A/C) Diagnostics - Pressure Zone D  Go to Step 8 
8 Operate the system in order to verify the test results.
Did you find the same results?		 - System OK Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual
Fig 1: A/C System Pressure - Zone Classification
GM1233218Courtesy of GENERAL MOTORS CORP.
A/C Performance Table

Ambient Air Temperature Relative Humidity Service Port Pressure Maximum Left Center Discharge Air Temperature
Low Side High Side
13-18° C (55-65° F) 0-100% 175-232 kPa (25-34 psi) 810-1 030 kPa (117-150 psi) 12° C (53.6° F)
18-24° C (65-75° F) Below 40% 175-245 kPa (25-36 psi) 970-1 230 kPa (140-179 psi) 11° C (51.8° F)
Above 40% 175-267 kPa (25-39 psi) 960-1 200 kPa (139-175 psi) 14° C (57.2° F)
24-29° C (75-85° F) Below 35% 191-268 kPa (27-39 psi) 1 170-1 390 kPa (169-202 psi) 13° C (55.4° F)
35-50% 202-274 kPa (29-40 psi) 1 150-1 370 kPa (166-199 psi) 14° C (57.2° F)
Above 50% 210-287 kPa (30-42 psi) 1 140-1 340 kPa (165-195 psi) 16° C (60.8° F)
29-35° C (85-95° F) Below 30% 219-296 kPa (31-43 psi) 1 330-1 580 kPa (193-230 psi) 15° C (59.0° F)
30-50% 225-303 kPa (32-44 psi) 1 310-1 550 kPa (190-225 psi) 17° C (62.6° F)
Above 50% 234-312 kPa (34-46 psi) 1 290-1 510 kPa (187-220 psi) 18° C (64.4° F)
35-41° C (95-105° F) Below 20% 250-326 kPa (36-48 psi) 1 530-1 780 kPa (222-259 psi) 18° C (64.4° F)
20-40% 253-329 kPa (36-48 psi) 1 510-1 750 kPa (219-254 psi) 19° C (66.2° F)
Above 40% 260-333 kPa (37-49 psi) 1 490-1 720 kPa (216-250 psi) 20° C (68.0° F)
41-46° C (105-115° F) Below 20% 284-353 kPa (41-52 psi) 1 720-1 940 kPa (249-282 psi) 21° C (69.8° F)
Above 20% 286-354 kPa (41-52 psi) 1 700-1 900 kPa (246-276 psi) 22° C (71.6° F)
46-49° C (115-120° F) Below 30% 313-369 kPa (45-54 psi) 1 860-2 020 kPa (270-294 psi) 23° C (73.4° F)
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