GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 DeVille 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Air Conditioning (A/C) System Performance Test
Table 1: A/C Performance Table

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 .
  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 5-6 inches.
  3. Select the following HVAC control settings:
    4. • The A/C is ON
    • The maximum blower speed
    • The Vent mode
    • The coldest temperature setting
    • All A/C outlets are OPEN
  4. Install the temperature probes of the J 43600 in the left and right center A/C air outlets.
  5. Apply the parking brake.
  6. Place the transaxle/transmission in one of the following positions:
    7. • PARK (Automatic)
    • NEUTRAL (Manual)
  7. Start the engine.
  8. Operate the A/C system for 5 minutes.
  9. Inspect A/C components for the following conditions:
    10. • Abnormal frost areas
    • Unusual noises

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

  10. Print the following information:
    11. • The outlet air temperatures
    • The low-side pressure
    • The high-side pressure
  11. Compare the low and high side pressures and the output temperatures to the table below.

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

--

Go to Step 4

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 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 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 - Automatic

A/C System Pressure - Zone Classification
Object Number: 1411344 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%

150-265 kPa (22-38 psi)

510-1070 kPa (74-155 psi)

9°C (48°F)

19-24°C (66-75°F)

Below 40%

155-283 kPa (226-41 psi)

640-1200 kPa (93-174 psi)

9°C (48°F)

Above 40%

180-311 kPa (26-45 psi)

670-1180 kPa (97-171 psi)

11°C (52°F)

25-29°C (76-85°F)

Below 35%

194-315 kPa (28-46 psi)

820-1340 kPa (119-194 psi)

11°C (52°F)

35-50%

212-326 kPa (31-47 psi)

850-1320 kPa (123-192 psi)

12°C (54°F)

Above 50%

225-349 kPa (33-51 psi)

840-1300 kPa (122-189 psi)

14°C (57°F)

33-35°C (86-95°F)

Below 30%

223-360 kPa (32-52 psi)

970-1530 kPa (141-222 psi)

14°C (57°F)

30-50%

237-374 kPa (34-54 psi)

990-1510 kPa (144-219 psi)

16°C (61°F)

Above 50%

255-395 kPa (37-57 psi)

990-1490 kPa (144-216 psi)

19°C (66°F)

36-41°C (96-105°F)

Below 20%

253-406 kPa (37-59 psi)

1140-1750 kPa (165-254 psi)

16°C (61°F)

20-40%

262-415 kPa (38-60 psi)

1160-1730 kPa (168-251 psi)

18°C (64°F)

Above 40%

281-428 kPa (41-62 psi)

1180-1700 kPa (171-247 psi)

20°C (68°F)

42-46°C (106-115°F)

Below 20%

288-447 kPa (42-65 psi)

1320-1920 kPa (192-279 psi)

19°C (66°F)

Above 20%

297-455 kPa (43-66 psi)

1340-1900 kPa (194-276 psi)

21°C (70°F)

47-49°C (116-120°F)

Below 30%

327-473 kPa (47-69 psi)

1490-2010 kPa (216-292 psi)

21°C (70°F)