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

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2004 🢒 Colorado Pickup - 4WD 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Air Conditioning (A/C) System Performance Test

Table 1:

A/C Performance Table

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 temperatures.

Step

Action

Values

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 about 2 minutes.
Turn OFF the ignition.
Install the J 43600 .
Record the ambient air temperature displayed on the J 43600 .
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

Important: Record the relative humidity and the ambient air temperature at the time of the test.

Close the vehicle doors and windows.
Open the drivers door window 12.7-15.2 cm (5-6 inches).
Select the following HVAC control settings:

•	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

Install the temperature probes of the J 43600 in the left and right center panel air outlets.
Apply the parking brake.
Place the transaxle/transmission in one of the following positions:

•	PARK (Automatic)

•	NEUTRAL (Manual)

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

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.
RESET the J 43600 and 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 greater 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

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%	150-266 kPa (22-39 psi)	740-1020 kPa (107-148 psi)	12°C (54°F)
19-24°C (66-75°F)	Less than 40%	150-231 kPa (22-34 psi)	970-1300 kPa (141-189 psi)	10°C (50°F)
19-24°C (66-75°F)	Greater than 40%	169-271 kPa (25-39 psi)	960-1320 kPa (139-192 psi)	14°C (57°F)
25-29°C (76-85°F)	Less than 35%	167-248 kPa (24-36 psi)	1210-1510 kPa (176-219 psi)	12°C (54°F)
	35-50%	186-254 kPa (27-37 psi)	1220-1530 kPa (177-222 psi)	13°C (55°F)
	Greater than 50%	201-266 kPa (29-39 psi)	1220-1560 kPa (177-226 psi)	14°C (57°F)
30-35°C (86-95°F)	Less than 30%	200-276 kPa (29-40 psi)	1410-1760 kPa (205-255 psi)	15°C (59°F)
	30-50%	206-270 kPa (30-39 psi)	1430-1800 kPa (208-261 psi)	15°C (59°F)
	Greater than 50%	214-261 kPa (31-38 psi)	1450-1860 kPa (210-270 psi)	16°C (61°F)
36-41°C (96-105°F)	Less than 20%	242-316 kPa (35-46 psi)	1640-1990 kPa (238-289 psi)	18°C (64°F)
	20-40%	239-296 kPa (35-43 psi)	1660-2040 kPa (241-296 psi)	18°C (64°F)
	Greater than 40%	233-275 kPa (34-40 psi)	1700-2100 kPa (247-305 psi)	17°C (63°F)
42-46°C (106-115°F)	Less than 20%	286-347 kPa (42-50 psi)	1880-2190 kPa (273-318 psi)	21°C (70°F)
42-46°C (106-115°F)	Greater than 20%	276-315 kPa (40-46 psi)	1910-2260 kPa (277-328 psi)	20°C (68°F)
47-49°C (116-120°F)	Less than 30%	307-345 kPa (45-50 psi)	2110-2350 kPa (306-341 psi)	22°C (72°F)

A/C System Pressure Zone Classification