Air Conditioning (A/C) System Performance Test. Buick Century 2003

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2003 🢒 Century 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Air Conditioning (A/C) System Performance Test

Table 1:

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.

This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.

This step measures the performance of the A/C system.

This step is to allow for vehicle variations as well as high ambient air temperatures.

Step

Action

Value(s)

Yes

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.

Park the vehicle inside or in the shade.
Open the windows in order to ventilate the interior of the vehicle.
If the A/C system was operating, allow the A/C system to equalize for 2 minutes.
Turn OFF the ignition.
Install the J 43600 ACR 2000 Air Conditioning Service Center.
Record the ambient air temperature displayed on the J 43600 .
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

Important: Record the relative humidity and the ambient air temperature AT THE TIME OF THE TEST.

Close the vehicle doors and windows.
Open the driver door window 12.7-15.2 cm (5-6 in).
Select the following HVAC control setting:

•	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

Install the temperature probes of the J 43600 in the left and right center panel air outlets.
Apply the parking brake.
Place the transmission in PARK.
Start the engine.
Operate the A/C system for 5 minutes.
Inspect A/C components for the following conditions:

•	Abnormal frost areas

•	Unusual noises

Important: When performing this step it is necessary to press the RESET button on the J 43600 before pressing the PRINT button.

Print the following information:

•	The panel outlet air temperatures

•	The low-side pressure

•	The high-side pressure

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

If the pressures and temperatures recorded do not fall within the specified ranges:

Continue to operate the A/C system for an additional 5 minutes.
Record the pressures and temperatures again.
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

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

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

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

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

Operate the system in order to verify the test results.

Did you find the same results?

System OK

Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic in HVAC Systems - Automatic

A/C System Pressure - Zone Classification

A/C Performance Table

Ambient Air Temperature	Relative Humidity	Service Port Pressure		Maximum Left Center Discharge Air Temperature
Ambient Air Temperature	Relative Humidity	Low Side	High Side	Maximum Left Center Discharge Air Temperature
13-18°C (55-65°F)	0-100%	175-243 kPa (25-35 psi)	640-990 kPa (93-144 psi)	12°C (53.6°F)
19-24°C (66-75°F)	Below 40%	175-256 kPa (25-37 psi)	750-1120 kPa (109-163 psi)	12°C (53.6°F)
19-24°C (66-75°F)	Above 40%	184-287 kPa (27-42 psi)	820-1240 kPa (119-180 psi)	15°C (59°F)
25-29°C (76-85°F)	Below 35%	196-277 kPa (28-40 psi)	960-1280 kPa (139-186 psi)	14°C (57.2°F)
	35-60%	212-290 kPa (31-42 psi)	1020-1340 kPa (148-195 psi)	16°C (60.8°F)
	Above 60%	223-316 kPa (32-46 psi)	1070-1460 kPa (155-212 psi)	18°C (64.4°F)
30-35°C (86-95°F)	Below 30%	220-303 kPa (32-44 psi)	1130-1480 kPa (164-215 psi)	17°C (62.6°F)
	30-50%	223-322 kPa (34-47 psi)	1190-1570 kPa (173-228 psi)	19°C (66.2°F)
	Above 50%	250-350 kPa (36-51 psi)	1260-1710 kPa (183-248 psi)	21°C (69.8°F)
36-41°C (96-105°F)	Below 20%	245-324 kPa (36-47 psi)	1300-1630 kPa (189-237 psi)	19°C (66.2°F)
	20-40%	254-344 kPa (37-50 psi)	1350-1750 kPa (196-254 psi)	21°C (69.8°F)
	Above 40%	273-364 kPa (40-53 psi)	1440-1860 kPa (209-270 psi)	23°C (73.4°F)
42-46°C (106-115°F)	Below 20%	273-348 kPa (40-51 psi)	1440-1860 kPa (209-270 psi)	22°C (71.6°F)
42-46°C (106-115°F)	Above 20%	284-370 kPa (41-54 psi)	1550-1930 kPa (218-261 psi)	24°C (75.2°F)
47-49°C (116-120°F)	Below 30%	308-374 kPa (45-54 psi)	1720-1970 kPa (250-286 psi)	24°C (75.2°F)