GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2005 🢒 Montana - 4WD 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Air Conditioning (A/C) System Performance Test
Table 1: A/C Performance Table
Table 2: A/C Performance Table - with Rear A/C

Test Description

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

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.

  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 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 Air Conditioning Service Center.
  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?

Greater than 16°C (60°F) - 345 kPa (50 psi)

Greater than 24°C (75°F) - 483 kPa (70 psi)

Greater 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 in).
  3. Select the following HVAC control settings:
    4. • A/C setting
    • Recirculation mode
    • Maximum blower speed
    • Panel mode
    • Coldest temperature setting
    • Open all panel air outlets
    • If equipped, maximum auxiliary blower speed
    • If equipped, coldest auxiliary temperature setting
    • If equipped, open all auxiliary air outlets
  4. Install the temperature probes of J 43600 in the left and right center panel air outlets.
  5. Apply the parking brake.
  6. Place the transaxle in PARK.
  7. Start the engine.
  8. Operate the A/C system for 5 minutes.
  9. Inspect the A/C components for abnormal frost areas and for unusual noises.

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

  10. Print the following information:
    11. • The panel outlet air temperature
    • The low-side pressure
    • The high-side pressure
  11. Compare the printed information 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 temperature recorded do not fall within the specified ranges, perform the following procedure:

  1. Continue to operate the A/C system for an additional 5 minutes.
  2. RESET J 43600 and record the pressures and temperature again.
  3. Compare the new results 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 pressures fall within the specified ranges, but the panel outlet temperature does 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

A/C System Pressure -- Zone Classification
Object Number: 668773 Size: MF

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%

197-225 kPa (29-33 psi)

1100-1230 kPa (160-178 psi)

9°C (48°F)

19-23°C (66-75°F)

Below 40%

191-228 kPa (28-33 psi)

1060-1230 kPa (154-178 psi)

10°C (50°F)

Above 40%

202-246 kPa (29-36 psi)

1100-1370 kPa (160-199 psi)

12°C (54°F)

24-29°C (76-85°F)

Below 35%

194-230 kPa (28-33 psi)

1130-1220 kPa (164-177 psi)

11°C (52°F)

35-60%

198-246 kPa (29-36 psi)

1090-1320 kPa (158-191 psi)

12°C (54°F)

Above 60%

236-311 kPa (34-45 psi)

1140-1580 kPa (165-229 psi)

15°C (59°F)

30-35°C (86-95°F)

Below 30%

208-256 kPa (30-37 psi)

1230-1370 kPa (178-199 psi)

14°C (57°F)

30-50%

215-284 kPa (31-41 psi)

1180-1540 kPa (171-223 psi)

16°C (61°F)

Above 50%

236-311 kPa (34-45 psi)

1290-1750 kPa (187-254 psi)

18°C (64°F)

36-40°C (96-105°F)

Below 20%

235-298 kPa (34-43 psi)

1340-1600 kPa (194-232 psi)

17°C (63°F)

20-40%

246-315 kPa (36-46 psi)

1340-1700 kPa (194-247 psi)

18°C (64°F)

Above 40%

260-348 kPa (38-51 psi)

1410-1940 kPa (204-281 psi)

21°C (70°F)

41-46°C (106-115°F)

Below 20%

266-339 kPa (39-49 psi)

1550-1820 kPa (225-264 psi)

21°C (70°F)

Above 20%

280-369 kPa (41-54 psi)

1530-2000 kPa (222-290 psi)

23°C (73°F)

47-49°C (116-120°F)

Below 30%

304-378 kPa (44-55 psi)

1870-2020 kPa (271-293 psi)

24°C (75°F)

A/C System Pressure -- Zone Classification (with Rear A/C)
Object Number: 669505 Size: MF

A/C Performance Table - with Rear A/C

Ambient Air Temperature

Relative Humidity

Service Port Pressure

Maximum Left Center A/C Discharge Air Temperature

Maximum Left/Top Rear A/C Discharge Air Temperature

Low Side

High Side

13-18°C (55-65°F)

0-100%

251-270 kPa (36-39 psi)

650-990 kPa (94-144 psi)

12°C (54°F)

18°C (64°F)

19-23°C (66-75°F)

Below 40%

257-282 kPa (37-41 psi)

680-1190 kPa (99-173 psi)

13°C (55°F)

19°C (66°F)

Above 40%

262-368 kPa (38-53 psi)

740-1230 kPa (107-178 psi)

22°C (72°F)

25°C (77°F)

24-29°C (76-85°F)

Below 35%

255-310 kPa (37-45 psi)

970-1370 kPa (141-199 psi)

16°C (61°F)

21°C (70°F)

35-60%

256-337 kPa (37-49 psi)

1010-1430 kPa (147-207 psi)

18°C (64°F)

23°C (73°F)

Above 60%

262-422 kPa (38-61 psi)

1100-1380 kPa (160-200 psi)

26°C (79°F)

29°C (84°F)

30-35°C (86-95°F)

Below 30%

280-348 kPa (41-51 psi)

1180-1570 kPa (171-228 psi)

19°C (66°F)

24°C (75°F)

30-50%

280-406 kPa (41-59 psi)

1200-1610 kPa (174-234 psi)

24°C (75°F)

29°C (84°F)

Above 50%

309-456 kPa (41-59 psi)

1290-1590 kPa (187-231 psi)

28°C (82°F)

32°C (90°F)

36-40°C (96-105°F)

Below 20%

312-387 kPa (45-56 psi)

1370-1770 kPa (1992-257 psi)

23°C (73°F)

28°C (82°F)

20-40%

312-446 kPa (45-65 psi)

1370-1830 kPa (199-265 psi)

27°C (81°F)

33°C (91°F)

Above 40%

342-496 kPa (50-72 psi)

1470-1810 kPa (213-263 psi)

31°C (88°F)

36°C (97°F)

41-46°C (106-115°F)

Below 20%

350-456 kPa (51-66 psi)

1550-2030 kPa (225-295 psi)

28°C (82°F)

34°C (93°F)

Above 20%

359-493 kPa (52-72 psi)

1630-2050 kPa (236-297 psi)

31°C (88°F)

37°C (99°F)

47-49°C (116-120°F)

Below 30%

405-543 kPa (59-79 psi)

1840-2180 kPa (267-316 psi)

34°C (93°F)

42°C (108°F)