GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Eldorado 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Air Conditioning (A/C) System Performance Test
Table 1: A/C Performance Table

Test Description

The following test measures the A/C system operating efficiency by comparing:

    • The ambient air temperature
    • The ambient air humidity
    • The pressure at the high-pressure side of the refrigeration system
    • The pressure at the low-pressure side of the refrigeration system
    • The temperature of the air being discharged into the passenger compartment

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step determines if there is enough refrigerant in the A/C system in order 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 air temperatures.

Step

Action

Value(s)

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 (about 2 minutes).
  4. Ensure that the ignition key is in the OFF position.
  5. Install the J 43600 .
  6. Record the ambient air temperature displayed on the J 43600 .
  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 ambient air temperature AT THE TIME OF THE TEST.

  1. Close the vehicle doors and windows.
  2. Open the driver door window 5-6 inches.
  3. Set the HVAC control to the following positions:
    4. • The A/C on
    • The blower control to the highest position
    • The HVAC control assembly to discharge air through the A/C outlets
    • The temperature control to the coldest position
    • All A/C outlets OPEN
  4. Install thermometers in the left and right center A/C air outlets.
  5. Apply the parking brake.
  6. Place the transaxle/transmission in PARK.
  7. Start the engine and allow to idle.
  8. Operate the A/C system for 5 minutes.
  9. Inspect for the following:
    10. •  Abnormal frost areas
    • Unusual noises
  10. Record 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. 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 higher than the specified range and the high side pressure within or lower 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 higher than the specified ranges?

--

Go to Air Conditioning (A/C) Diagnostics - Pressure Zone C

Go to Step 7

7

Is the low side pressure within or lower than the specified range and the high side pressure higher 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 in HVAC Systems - Automatic

A/C System Pressure -- Zone Classification
Object Number: 466373 Size: MF

A/C Performance Table

Ambient Air Temperature

Relative Humidity

Service Port Pressure

Maximum Left Center Discharge Air Temperature

Low Side

High Side

16°C (60°F)

0-100%

165-207 kPa (24-30 psi)

1089-1296 kPa (158-188 psi)

9°C (49°F)

21°C (70°F)

Below 40%

172-214 kPa (25-31 psi)

1151-1358 kPa (167-197 psi)

10°C (50°F)

Above 40%

193-234 kPa (28-34 psi)

876-1083 kPa (127-157 psi)

12°C (53°F)

27°C (80°F)

Below 35%

172-214 kPa (25-31 psi)

1020-1227 kPa (148-178 psi)

11°C (51°F)

35-60%

179-221 kPa (26-32 psi)

1007-1214 kPa (146-176 psi)

11°C (52°F)

Above 60%

228-269 kPa (33-39 psi)

1255-1462 kPa (182-212 psi)

14°C (57°F)

32°C (90°F)

Below 30%

207-248 kPa (30-36 psi)

1110-1317 kPa (161-191 psi)

13°C (55°F)

Above 30%

228-269 kPa (33-39 psi)

1193-1400 kPa (173-203 psi)

14°C (58°F)

38°C (100°F)

Below 20%

207-262 kPa (31-41 psi)

1255-1531 kPa (182-222 psi)

14°C (57°F)

20-40%

214-296 kPa (33-43 psi)

1310-1586 kPa (190-230 psi)

15°C (59°F)

Above 40%

248-317 kPa (36-46 psi)

1351-1627 kPa (196-236 psi)

17°C (62°F)

43°C (110°F)

Below 20%

255-324 kPa (37-47 psi)

1503-1779 kPa (218-258 psi)

17°C (63°F)

Above 20%

310-379 kPa (45-55 psi)

1538-1813 kPa (223-263 psi)

22°C (71°F)

49°C (120°F)

Below 30%

345-414 kPa (50-60 psi)

1800-2075 kPa (261-301 psi)

24°C (75°F)