Air Conditioning (A/C) System Performance Test. Chevrolet Impala 2001

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2001 🢒 Impala 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Air Conditioning (A/C) System Performance Test

Table 1:

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

Test Description

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

This step determines if there is enough refrigerant in the A/C system in order 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 (about 2 minutes).
Ensure that the ignition key is in the OFF position.
Install the J 43600 ACR2000m Refrigerent Station.
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 5-6 inches.
Set the HVAC control to the following positions:

•	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

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

•	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 after the 5 minute operating time.

Record 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.
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 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

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

A/C System Pressure - Zone Classification

A/C Performance Table

Relative Humidity	Ambient Air Temperature		Maximum Low Side Pressure		Engine Speed	Maximum Right Center Air Outlet Temperature		Maximum High Side Pressure
%	°F	°C	PSI	kPa	RPM	°F	°C	PSI	kPa
20	70	21	37	255	2000	46	8	225	1551
	80	27	37	255		47	8	275	1896
	90	32	37	255		53	12	325	2241
	100	38	38	262		54	12	325	2241
30	70	21	37	255	2000	48	9	240	1655
	80	27	37	255		50	10	285	1965
	90	32	39	269		57	14	340	2344
	100	38	43	296		60	16	360	2482
40	70	21	37	255	2000	49	9	260	1793
	80	27	37	255		53	12	305	2103
	90	32	42	290		60	16	355	3137
	100	38	49	338		66	19	395	2724
50	70	21	37	255	2000	51	11	275	1896
	80	27	39	269		56	13	320	2206
	90	32	46	317		63	17	375	2586
	100	38	55	379		72	22	430	2965
60	70	21	37	255	2000	53	12	290	2000
	80	27	42	290		59	15	340	2344
	90	32	49	338		66	19	390	2689
	100	38	60	414		78	26	445	3068
70	70	21	37	255	2000	55	13	305	2103
	80	27	45	310		62	17	355	2448
	90	32	53	365		70	21	405	2792
80	70	21	41	283	2000	56	13	320	2206
	80	27	48	331		65	18	370	2551
	90	32	57	393		73	23	420	2896
90	70	21	45	310	2000	58	14	335	2310
90	80	27	52	359	2000	68	20	385	2655