Content .. 2297 2298 2299 2300 ..
Chevrolet Silverado / GMC Sierra. Manual - part 2299
Fig. 1: A/C System Pressure (6.6L)
Courtesy of GENERAL MOTORS CORP.
A/C Performance Table - Diesel Engine
Ambient Air
Temperature
Relative
Humidity
Service Port Pressure
Maximum
Discharge
Air
Temperature
Low Side
High Side
13-18°C (55-
65°F)
0-100%
150-279 kPa (22-41
psi)
420-1140 kPa (61-165
psi)
9°C (48°F)
19-24°C (66-
75°F)
Below 40%
150-298 kPa (22-43
psi)
531-1240 kPa (77-180
psi)
11°C (52°F)
Above 40%
176-366 kPa (26-53
psi)
760-1510 kPa (110-
219 psi)
14°C (57°F)
216-359 kPa (31-52
990-1550 kPa (143-
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
AIR CONDITIONING (A/C) SYSTEM PERFORMANCE TEST (GAS ENGINE W/ ELECTRIC
COOLING FAN)
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.
25-29°C (76-
85°F)
Below 35%
psi)
225 psi)
15°C (59°F)
35-50%
250-382 kPa (36-55
psi)
1130-1640 kPa (164-
238 psi)
16°C (61°F)
Above 50%
275-430 kPa (40-62
psi)
1230-1820 kPa (178-
264 psi)
18°C (64°F)
30-35°C (86-
95°F)
Below 30%
287-434 kPa (42-63
psi)
1350-1930 kPa (195-
280 psi)
19°C (66°F)
30-50%
311-463 kPa (45-67
psi)
1440-2040 kPa (209-
296 psi)
21°C (70°F)
Above 50%
342-506 kPa (50-73
psi)
1560-2190 kPa (226-
318 psi)
23°C (73°F)
36-41°C (96-
105°F)
Below 20%
366-506 kPa (53-73
psi)
1750-2300 kPa (254-
334 psi)
23°C (73°F)
20-40%
382-531 kPa (55-77
psi)
1800-2390 kPa (261-
347 psi)
25°C (77°F)
Above 40%
409-557 kPa (59-81
psi)
1900-2480 kPa (276-
360 psi)
27°C (81°F)
42-46°C (106-
115°F)
Below 20%
452-575 kPa (66-84
psi)
2180-2660 kPa (316-
386 psi)
27°C (81°F)
Above 20%
465-599 kPa (68-87
psi)
2220-2730 kPa (322-
396 psi)
29°C (84°F)
47-49°C (116-
120°F)
Below 30%
535-629 kPa (78-91
psi)
2580-2900 kPa (375-
421 psi)
30°C (86°F)
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
1: This step determines if the A/C system has at least the minimum refrigerant charge
required to operate the system without damage.
2: This step measures the performance of the A/C system.
3: This step is to allow for vehicle variations as well as high ambient air 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.
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
Refrigerant Station. See Special
Tools.
6. Record the ambient air temperature
displayed on the J 43600 . See
Special Tools.
7. Record the low and high side
STATIC pressure readings.
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
1. Close the vehicle doors and
windows.
IMPORTANT:
Record the relative humidity and the
ambient air temperature at the time of
the test.
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
2
2. Open the drivers door window 127-
152 mm (5-6 inches).
3. Select the following HVAC control
settings:
The A/C ON
The coldest temperature
setting
The maximum blower speed
The IP panel outlet mode
All IP panel outlets are OPEN
Recirculation mode
4. Install the temperature probes to the
J 43600 in the left and right center
air outlets. See Special Tools.
5. Apply the parking brake.
6. Place the transaxle/transmission in
one of the following positions:
PARK for Automatic
NEUTRAL for Manual
7. Start the engine.
8. Operate the A/C system for 5
minutes.
9. Inspect A/C components for the
following conditions:
Abnormal frost areas
Unusual noises
10. Print the following information:
The panel outlet air
temperatures
IMPORTANT:
Press the RESET button, before using
the print function of the J 43600 . See
Special Tools.
-
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Content .. 2297 2298 2299 2300 ..