GM Service Manual Online
For 1990-2009 cars only
Table 1: A/C Performance Table - Front Only
Table 2: A/C Performance Table - With Rear A/C

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

    • The current ambient air temperature
    • The current relative humidity
    • The high side pressure of the A/C system
    • The low side pressure of the A/C system
    • The temperature of the air being discharged into the passenger compartment

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.

Step

Action

Values

Yes

No

Important: 

   • The ambient air temperature 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 Refrigerant Station.
  6. Record the ambient air temperature displayed on the J 43600 .
  7. Record the low and high side STATIC pressure readings.

Are both the low side and high side pressures within the specified value?

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)

Go to Step 2

Go to Leak Testing

2

    Important: Record the relative humidity and the ambient air temperature at the time of the test.

  1. Close the vehicle doors and windows.
  2. Open the drivers door window 12.7-15.2 cm (5-6 inches).
  3. Select the following HVAC control settings:
  4. • The A/C is ON.
    • The coldest temperature setting
    • The maximum blower speed
    • Recirculation mode
    • The I/P panel outlet mode
    • All I/P panel outlets are OPEN.
    • The passenger side of a Dual Zone HVAC control module is turned OFF.
    • The coldest temperature setting on the auxiliary HVAC control assembly
    • The maximum blower speed selected on the auxiliary blower controls
  5. Install the temperature probes of the J 43600 in the left and right center panel air outlets.
  6. Apply the parking brake.
  7. Place the transaxle/transmission in one of the following positions:
  8. • PARK (Automatic)
    • NEUTRAL (Manual)
  9. Start the engine.
  10. Operate the A/C system for 5 minutes.
  11. Inspect A/C components for the following conditions:
  12. • Abnormal frost areas
    • Unusual noises

    Important: Press the RESET button, before using the print function of the J 43600 .

  13. Print the following information:
  14. • The panel outlet air temperatures
    • The low-side pressure
    • The high-side pressure
  15. Compare the low and high side pressures and the panel output temperatures to the table below.

Does all the data recorded fall within the specified ranges of the table below?

--

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. RESET the J 43600 and record the pressures and temperatures again.
  3. Compare the low and high side pressures and the panel output temperature to the table below.

Does all the data recorded fall within the specified ranges of the table below?

--

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 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

A/C Performance Table - Front Only

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%

175-194 kPa (25-28 psi)

630-1170 kPa (91-170 psi)

7°C (45°F)

19-24°C (66-75°F)

Below 40%

175-204 kPa (25-27 psi)

620-1130 kPa (90-164 psi)

7°C (45°F)

Above 40%

175-240 kPa (25-35 psi)

820-1320 kPa (119-192 psi)

10°C (50°F)

25-29°C (76-85°F)

Below 35%

175-238 kPa (25-35 psi)

930-1300 kPa (135-189 psi)

10°C (50°F)

35-60%

175-249 kPa (25-36 psi)

1120-1350 kPa (148-196 psi)

11°C (52°F)

Above 60%

175-271 kPa (25-39 psi)

1100-1450 kPa (160-210 psi)

13°C (56°F)

30-35°C (86-95°F)

Below 30%

184-282 kPa (27-41 psi)

1160-1530 kPa (168-222 psi)

14°C (57°F)

30-50%

194-292 kPa (28-42 psi)

1210-1560 kPa (176-226 psi)

15°C (59°F)

Above 50%

209-307 kPa (30-45 psi)

1270-1600 kPa (184-232 psi)

17°C (63°F)

36-41°C (96-105°F)

Below 20%

232-326 kPa (34-47 psi)

1430-1790 kPa (208-260 psi)

17°C (63°F)

20-40%

237-332 kPa (34-48 psi)

1440-1770 kPa (209-257 psi)

18°C (64°F)

Above 40%

247-338 kPa (36-49 psi)

1460-1760 kPa (212-255 psi)

19°C (66°F)

42-46°C (106-115°F)

Below 20%

383-367 kPa (41-53 psi)

1710-2010 kPa (248-292 psi)

20°C (68°F)

Above 20%

286-369 kPa (42-54 psi)

1710-1960 kPa (248-285 psi)

21°C (70°F)

47-49°C (116-120°F)

Below 30%

327-392 kPa (48-57 psi)

1930-2110 kPa (280-306 psi)

23°C (73°F)


Object Number: 1235228  Size: MF

A/C Performance Table - With Rear A/C

Ambient Temperature

Relative Humidity

Low Side Service Port Pressure

High Side Service Port Pressure

Maximum Left Center Discharge Air Temperature

Maximum Left Side Rear Discharge Air Temperature

13-18°C (55-65°F)

0-100%

175-204 kPa (25-30 psi)

360-870 kPa (52-126 psi)

12°C (53°F)

7°C (45°F)

19-24°C (66-75°F)

Less than 40%

175-235 kPa (25-34 psi)

490-1010 kPa (71-147 psi)

12°C (53°F)

10°C (50°F)

Greater than 40%

175-263 kPa (25-42 psi)

620-1120 kPa (90-163 psi)

14°C (57°F)

12°C (54°F)

25-29°C (76-85°F)

Less than 35%

177-290 kPa (26-42 psi)

870-1270 kPa (126-184 psi)

16°C (61°F)

14°C (57°F)

35-60%

191-295 kPa (28-43 psi)

920-1290 kPa (134-187 psi)

16°C (61°F)

15°C (59°F)

Greater than 60%

202-304 kPa (29-44 psi)

960-1330 kPa (139-193 psi)

17°C (63°F)

16°C (61°F)

30-35°C (86-95°F)

Less than 30%

244-362 kPa (35-53 psi)

1160-1590 kPa (168-231 psi)

22°C (72°F)

19°C (66°F)

30-50%

249-358 kPa (36-52 psi)

1180-1590 kPa (171-231 psi)

21°C (70°F)

20°C (68°F)

Greater than 50%

255-353 kPa (37-51 psi)

1210-1580 kPa (176-229 psi)

20°C (68°F)

22°C (72°F)

36-41°C (96-105°F)

Less than 20%

325-441 kPa (47-62 psi)

1520-1940 kPa (221-282 psi)

28°C (82°F)

25°C (77°F)

20-40%

323-428 kPa (46-60 psi)

1510-1900 kPa (219-276 psi)

26°C (79°F)

25°C (77°F)

Greater than 40%

320-415 kPa (59-73 psi)

1510-1860 kPa (219-270 psi)

25°C (77°F)

26°C (79°F)

42-46°C (106-115°F)

Less than 20%

407-506 kPa (59-70 psi)

1880-2230 kPa (273-324 psi)

33°C (91°F)

29°C (84°F)

Greater than 20%

401-485 kPa (58-70 psi)

1860-2160 kPa (270-314 psi)

30°C (86°F)

30°C (86°F)

47-49°C (116-120°F)

Less than 30%

466-532 kPa (68-77 psi)

2150-2360 kPa (312-343 psi)

34°C (93°F)

32°C (90°F)

A/C System Pressure -- Zone Classification With Rear A/C


Object Number: 886853  Size: MF