Content .. 2303 2304 2305 2306 ..
Chevrolet Silverado / GMC Sierra. Manual - part 2305
AIR CONDITIONING (A/C) DIAGNOSTICS - PRESSURE ZONE C
Conditioning Accumulator
Replacement (Non-HP2).
5. Evacuate and recharge the A/C system.
Refer to Refrigerant Recovery and
Recharging.
Is the repair complete?
Go to Step 13
-
12
1. Replace the A/C compressor. Refer to Air
Conditioning Compressor
Replacement (LY2, LY5, LH6, L76,
L92 and LMG) or Air Conditioning
Compressor Replacement
(LLY/LMM) or Air Conditioning
Compressor Replacement (LU3).
2. Evacuate and recharge the A/C system.
Refer to Refrigerant Recovery and
Recharging.
Is the repair complete?
Go to Step 13
-
13
Operate the system in order to verify the repair
Did you find and correct the condition?
System OK
Go to Symptoms
- HVAC Systems
- Automatic
Step
Action
Yes
No
DEFINITION: The low and the high side pressures are both higher than normal.
Restricted Condenser Air Flow
Cooling Fan Malfunction
Expansion Device Malfunction
Were you sent here from the A/C System
Performance Test?
Go to Air
Conditioning
(A/C) System
Performance
Test (Diesel
Engine) or Air
Conditioning
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
1
Go to Step 2
(A/C) System
Performance
Test (Gas
Engine w/
Electric Cooling
Fan) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine
w/Engine Driven
Fan)
2
1. With the engine idling, turn ON the A/C.
2. Inspect for proper cooling fan operation.
Refer to Cooling System Description
and Operation .
Are the cooling fans ON and operating
properly?
Go to Step 3
Go to Step 5
3
Visually inspect for the following:
Restricted air flow.
Damaged condenser cooling fins.
Inspect for missing or misaligned air
baffles.
Do the following conditions exist?
Go to Step 4
Go to Step 6
4
Repair the air flow restriction.
Is the repair complete?
Go to Step 9
-
5
Repair the cooling fan operation fault. Refer to
Fan Clutch Diagnosis .
Is the repair complete?
Go to Step 9
-
6
Feel the liquid line on both sides of the
CAUTION:
Refer to Moving Parts and Hot Surfaces Caution .
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
expansion device.Is the temperature the same
before and after the expansion device?
Go to Step 7
Go to Step 8
7
Replace the damaged/faulty orifice tube. Refer
to Expansion (Orifice) Tube Replacement.
Is the repair complete?
Go to Step 9
-
8
Air is in the refrigerant system, or the system is
overcharged. Refer to the view screen on the J
43600 ACR 2000 Refrigerant Station for
foreign gas content in the refrigerant. See
Special Tools.
Recover and recharge the A/C system. Refer to
Refrigerant Recovery and Recharging.
Is the repair complete?
Go to Step 9
-
9
1. Record the low and high side pressures
and the I/P outlet air temperature after
repairs are performed.
2. Compare the pressures and outlet
temperature to those listed in the A/C
Performance Chart. Refer to Air
Conditioning (A/C) System
Performance Test (Diesel Engine) or
Air Conditioning (A/C) System
Performance Test (Gas Engine w/
Electric Cooling Fan) or Air
Conditioning (A/C) System
Performance Test (Gas Engine
w/Engine Driven Fan).
Are the readings within the specified ranges?
Go to Step 10
Go to Air
Conditioning
(A/C) System
Performance
Test (Diesel
Engine) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine w/
Electric Cooling
Fan) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine
w/Engine Driven
Fan)
10
Operate the system in order to verify the repair.
Did you find and correct the condition?
Go to Symptoms
- HVAC Systems
- Manual
or
Go to Symptoms
- HVAC Systems
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
AIR CONDITIONING (A/C) DIAGNOSTICS - PRESSURE ZONE D
System OK
- Automatic
Step
Action
Yes
No
DEFINITION: The low side pressure is lower than normal and the high side pressure is
higher than normal.
A restriction in the A/C system.
1
Were you sent here from the A/C System
Performance Test?
Go to Step 2
Go to Air
Conditioning
(A/C) System
Performance
Test (Diesel
Engine) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine w/
Electric Cooling
Fan) or Air
Conditioning
(A/C) System
Performance
Test (Gas
Engine
w/Engine Driven
Fan)
2
Feel the liquid line before the expansion
device.Is the liquid line cold before the
expansion device?
CAUTION:
Refer to Moving Parts and Hot Surfaces Caution .
Go to Step 3
Go to Step 8
Feel along the surfaces of the following high
side components:
The compressor discharge hose
The condenser
2008 Chevrolet Silverado 1500
2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &
Silverado
Content .. 2303 2304 2305 2306 ..