Air Conditioning (A/C) System Performance Test. Chevrolet TrailBlazer

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2004 🢒 TrailBlazer - 2WD 🢒 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

The following test measures the A/C system under the following conditions:

•	The current ambient air temperature

•	The current ambient air 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.

This step determines if the A/C system has at least the minimum refrigerant charge 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 temperatures.

Step

Action

Values

Yes

Important:

•	The ambient 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.
Turn OFF the ignition.
Install the J 43600 .
Record the ambient 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 temperature at the time of the test.

Close the vehicle doors and windows.
Open the driver door window 5 to 6 inches.
Select the following HVAC control settings:

•	The A/C on

•	The maximum blower speed

•	The Panel mode

•	The coldest temperature setting

•	All A/C outlets OPEN

Install the temperature probes of the J 43600 .
Apply the parking brake.
Place the transaxle/transmission in PARK.
Start the engine.
Operate the A/C system for 5 minutes.
Inspect for the following conditions:

•	Abnormal frost areas

•	Unusual noises

Important: When using the print function of the J 43600 for this step, press the RESET button before pressing the PRINT button in order to capture the correct information.

Print the following information:

•	The outlet air temperatures

•	The low-side pressure

•	The high-side pressure

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 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.
Reset the J 43600 for this step, press the RESET and record the pressures and temperatures again.
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

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

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

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

Go to Symptoms - HVAC Systems - Automatic

A/C Performance Table

Ambient Temperature	Relative Humidity	Low Side Service Port Pressure	High Side Service Port Pressure	Maximum Left Center Discharge Air Temperature
13-18°C (55-65°F)	0-100%	175-207 kPa (25-30 psi)	1030-1220 kPa (135-175 psi)	7°C (45°F)
19-24°C (66-75°F)	Below 40%	175-254 kPa (25-37 psi)	1200-1430 kPa (160-200 psi)	11°C (52°F)
19-24°C (66-75°F)	Above 40%	175-262 kPa (25-38 psi)	1170-1400 kPa (170-210 psi)	11°C (52°F)
25-29°C (76-85°F)	Below 35%	208-288 kPa (30-42 psi)	1370-1570 kPa (150-190 psi)	14°C (57°F)
	35-50%	213-292 kPa (31-42 psi)	1350-1570 kPa (160-200 psi)	14°C (57°F)
	Above 50%	216-300 kPa (31-44 psi)	1340-1550 kPa (160-200 psi)	15°C (59°F)
30-35°C (86-95°F)	Below 30%	242-328 kPa (35-48 psi)	1510-1750 kPa (200-240 psi)	17°C (63°F)
	30-50%	246-335 kPa (36-49 psi)	1500-1740 kPa (200-240 psi)	17°C (63°F)
	Above 50%	252-346 kPa (37-50 psi)	1490-1730 kPa (200-240 psi)	19°C (66°F)
36-41°C (96-105°F)	Below 20%	281-366 kPa (41-53 psi)	1680-1920 kPa (240-280 psi)	19°C (66°F)
	20-40%	285-374 kPa (41-54 psi)	1670-1920 kPa (245-285 psi)	21°C (70°F)
	Above 40%	292-383 kPa (42-56 psi)	1670-1910 kPa (250-265 psi)	22°C (72°F)
42-46°C (106-115°F)	Below 20%	322-400 kPa (47-58 psi)	1850-2070 kPa (250-290 psi)	22°C (72°F)
42-46°C (106-115°F)	Above 20%	326-410 kPa (47-60 psi)	1840-2060 kPa (260-300 psi)	23°C (73°F)
47-49°C (116-120°F)	Below 30%	360-426 kPa (52-62 psi)	1990-2150 kPa (290-330 psi)	24°C (75°F)

A/C Performance Table -with Rear A/C

Ambient Air Temperature	Relative Humidity	Service Port Pressure		Maximum Discharge Air Temperature
Ambient Air Temperature	Relative Humidity	Low Side	High Side	Left Center	Rear Center
13-18°C (55-65°F)	0-100%	184-273 kPa (27-40 psi)	600-1080 kPa (87-157 psi)	19°C (66°F)	17°C (62°F)
19-24°C (66-75°F)	Below 40%	227-335 kPa (33-49 psi)	720-1210 kPa (105-176 psi)	19°C (66°F)	20°C (68°F)
19-24°C (66-75°F)	Above 40%	234-349 kPa (34-51 psi)	840-1330 kPa (122-193 psi)	22°C (72°F)	21°C (70°F)
25-29°C (76-85°F)	Below 35%	286-383 kPa (42-56 psi)	1050-1440 kPa (152-209 psi)	21°C (70°F)	23°C (73°F)
	35-50%	293-390 kPa (43-57 psi)	1110-1470 kPa (161-213 psi)	22°C (72°F)	23°C (73°F)
	Above 50%	298-403 kPa (43-59 psi)	1160-1550 kPa (168-225 psi)	24°C (75°F)	24°C (75°F)
30-35°C (86-95°F)	Below 30%	334-440 kPa (49-64 psi)	1310-1720 kPa (190-250 psi)	24°C (75°F)	27°C (81°F)
	30-50%	341-452 kPa (51-68 psi)	1340-1750 kPa (195-254 psi)	25°C (77°F)	27°C (81°F)
	Above 50%	350-469 kPa (51-68 psi)	1390-1800 kPa (202-261 psi)	27°C 81°F)	28°C (82°F)
36-41°C (96-105°F)	Below 20%	388-492 kPa (56-71 psi)	1600-2000 kPa (232-290 psi)	27°C (81°F)	30°C (86°F)
	20-40%	394-506 kPa (57-73 psi)	1620-2020 kPa (235-293 psi)	28°C (82°F)	31°C (88°F)
	Above 40%	406-520 kPa (59-76 psi)	1660-2040 kPa (241-296 psi)	29°C (84°F)	32°C (90°F)
42-46°C (106-115°F)	Below 20%	445-541 kPa (65-79 psi)	1910-2260 kPa (277-328 psi)	30°C (86°F)	34°C (93°F)
42-46°C (106-115°F)	Above 20%	452-557 kPa (66-81 psi)	1920-2260 kPa (279-328 psi)	31°C (88°F)	34°C (93°F)
47-49°C (116-120°F)	Below 30%	501-579 kPa (73-84 psi)	2180-2410 kPa (316-350 psi)	32°C (90°F)	36°C (97°F)