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Chevrolet Silverado / GMC Sierra. Manual - part 2301
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
The low-side pressure
The high-side pressure
11. Compare the low and high side
pressures and the panel 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
3
If the pressures and temperatures
recorded do not fall within the specified
ranges:
1. Continue to operate the A/C system
for an additional 5 minutes.
2. RESET the J 43600 and record the
pressures and temperatures again.
See Special Tools.
3. Compare the low and high side
pressures and the panel 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
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
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
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
A/C System Pressure Zone Classification - Gas Engine With Engine Driven Cooling Fan
6
-
(A/C)
Diagnostics -
Pressure
Zone C
Go to Step 7
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
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
or
Go to
Symptoms -
HVAC
Systems -
Automatic
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
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