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Makes 🢒 Buick 🢒 2006 🢒 Lucerne 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Air Conditioning (A/C) System Performance Test

Air Conditioning (A/C) System Performance Test 3.8L L26

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.
   • Use a scan tool to command the cooling fans to high speed.

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?

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 in).
  3. Select the following HVAC control settings:
    4. • The Vent mode
    • The Recirculation mode
    • The A/C set to ON
    • The coldest temperature setting
    • The maximum blower speed
    • All A/C outlets set to OPEN
  4. Install the temperature probes of the J 43600 in the left and right center panel 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. Using a scan tool, command the engine cooling fans to high speed.
  9. Operate the A/C system for 5 minutes.
  10. Inspect the A/C components for the following conditions:
    11. • Abnormal frost areas
    • Unusual noises

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

  11. Print the following information:
    12. • The panel outlet air temperatures
    • The low-side pressure
    • The high-side pressure
  12. 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. 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 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 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: 1688783 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%

130-227 kPa (19-33 psi)

482-799 kPa (70-116 psi)

9°C (48°F)

19-24°C (66-75°F)

Below 40%

130-234 kPa (19-34 psi)

613-950 kPa (89-138 psi)

10°C (50°F)

Above 40%

130-254 kPa (19-37 psi)

661-999 kPa (96-145 psi)

13°C (54°F)

25-29°C (76-85°F)

Below 35%

179-254 kPa (26-37 psi)

840-1123 kPa (122-163 psi)

13°C (54°F)

35-50%

192-261 kPa (28-38 psi)

861-1129 kPa (125-164 psi)

13°C (55°F)

Above 50%

199-268 kPa (29-39 psi)

881-1157 kPa (128-168 psi)

14°C (57°F)

30-35°C (86-95°F)

Below 30%

206-282 kPa (30-41 psi)

1019-1329 kPa (148-193 psi)

15°C (59°F)

30-50%

213-289 kPa (31-42 psi)

1040-1336 kPa (151-194 psi)

15°C (59°F)

Above 50%

220-289 kPa (32-42 psi)

1047-1357 kPa (152-197 psi)

18°C (63°F)

36-41°C (96-105°F)

Below 20%

234-310 kPa (34-45 psi)

1240-1550 kPa (180-225 psi)

18°C (63°F)

20-40%

241-310 kPa (35-45 psi)

1247-1550 kPa (181-225 psi)

18°C (64°F)

Above 40%

241-310 kPa (35-45 psi)

1260-1550 kPa (183-225 psi)

19°C (66°F)

42-46°C (106-115°F)

Below 20%

268-337 kPa (39-49 psi)

1460-1729 kPa (212-251 psi)

19°C (66°F)

Above 20%

268-330 kPa (39-48 psi)

1467-1729 kPa (213-251 psi)

20°C (68°F)

47-49°C (116-120°F)

Below 30%

296-358 kPa (43-52 psi)

1646-1908 kPa (239-277 psi)

23°C (72°F)

Air Conditioning (A/C) System Performance Test 4.6L LD8

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.
   • Use a scan tool to command the cooling fans to high speed.

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?

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 in).
  3. Select the following HVAC control settings:
    4. • The Vent mode
    • The Recirculation mode
    • The A/C set to ON
    • The coldest temperature setting
    • The maximum blower speed
    • All A/C outlets set to OPEN
  4. Install the temperature probes of the J 43600 in the left and right center panel 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. Using a scan tool, command the engine cooling fans to high speed.
  9. Operate the A/C system for 5 minutes.
  10. Inspect the A/C components for the following conditions:
    11. • Abnormal frost areas
    • Unusual noises

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

  11. Print the following information:
    12. • The panel outlet air temperatures
    • The low-side pressure
    • The high-side pressure
  12. 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. 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 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 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: 1688782 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%

130-213 kPa (19-31 psi)

537-868 kPa (78-126 psi)

9°C (48°F)

19-24°C (66-75°F)

Below 40%

130-241 kPa (19-35 psi)

668-1026 kPa (97-149 psi)

10°C (50°F)

Above 40%

130-261 kPa (19-38 psi)

730-1081 kPa (106-157 psi)

13°C (55°F)

25-29°C (76-85°F)

Below 35%

179-268 kPa (26-39 psi)

923-1212 kPa (134-176 psi)

13°C (54°F)

35-50%

192-282 kPa (28-41 psi)

937-1219 kPa (136-177 psi)

13°C (55°F)

Above 50%

206-296 kPa (30-43 psi)

957-1240 kPa (139-180 psi)

15°C (59°F)

30-35°C (86-95°F)

Below 30%

220-310 kPa (32-45 psi)

1123-1440 kPa (163-209 psi)

15°C (59°F)

30-50%

227-323 kPa (33-47 psi)

1129-1440 kPa (164-209 psi)

18°C (63°F)

Above 50%

241-337 kPa (35-49 psi)

1136-1446 kPa (165-210 psi)

18°C (64°F)

36-41°C (96-105°F)

Below 20%

261-351 kPa (38-51 psi)

1350-1667 kPa (196-242 psi)

18°C (64°F)

20-40%

268-358 kPa (39-52 psi)

1350-1660 kPa (196-241 psi)

19°C (66°F)

Above 40%

275-372 kPa (40-54 psi)

1357-1660 kPa (197-241 psi)

20°C (68°F)

42-46°C (106-115°F)

Below 20%

303-385 kPa (44-56 psi)

1591-1860 kPa (231-270 psi)

22°C (70°F)

Above 20%

310-392 kPa (45-57 psi)

1591-1853 kPa (231-269 psi)

23°C (72°F)

47-49°C (116-120°F)

Below 30%

344-427 kPa (50-62 psi)

1777-2039 kPa (258-296 psi)

25°C (77°F)