Chevrolet Silverado / GMC Sierra. Service manual — part 2303

Test (Gas Engine w/ Electric
Cooling Fan)Air
Conditioning (A/C) System
Performance Test (Gas
Engine w/Engine Driven
Fan) .

The discharge line is warm-to-
hot.

The suction line is cool-to-
warm.

Do the listed conditions exist?

Go to Step 8

Go to
Diagnostic
Starting
Point -
Heating,
Ventilation
and Air
Conditioning

7

The A/C system may be undercharged.

1. Leak test A/C system. Refer to Leak

Testing.

2. Recharge the A/C system to

specifications. Refer to Refrigerant
Recovery and Recharging.

Is the action complete?

-

Go to Step 14

-

8

The A/C system may be contaminated.
View the information screen on J 43600
ACS 2000 Air Conditioning Service
Center for detection of foreign gases in
the A/C system. See Special Tools.
Do foreign gases exist?

-

Go to Step 9 Go to Step 10

9

1. Evacuate the A/C system to a

scavenging tank. Refer to
Refrigerant Recovery and
Recharging.

2. Recharge the A/C system to

specifications.

Is the action complete?

-

Go to Step 14

-

The A/C system may contain too much
moisture or air.

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

10

1. Evacuate and recharge the A/C

system to specifications. Refer to
Refrigerant Recovery and
Recharging.

2. Operate the A/C system and inspect

the panel outlet air temperatures.
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 panel outlet temperatures within
the specified ranges of the A/C
Performance Test Table?

-

Go to Step 15 Go to Step 11

11

The A/C system may contain too much
refrigerant oil.

1. Recover the refrigerant from the

A/C system. Refer to Refrigerant
Recovery and Recharging.

2. Remove the accumulator. Refer to

Air Conditioning Accumulator
Replacement (Non-HP2).

3. Drain and measure the refrigerant

oil from the accumulator.

Was more than the specified amount of
refrigerant oil drained from the
accumulator?

148 ml (5

oz)

Go to Step 12 Go to Step 13

1. Reinstall the accumulator. Refer to

Air Conditioning Accumulator
Replacement (Non-HP2).

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

12

2. Flush the A/C system. Refer to

Flushing.

3. Recharge the A/C system. Refer to

Refrigerant Recovery and
Recharging.

Are the actions complete?

-

Go to Step 14

-

13

1. Add the specified amount of

refrigerant oil to the accumulator.
Refer to Refrigerant System
Capacities.

2. Install the accumulator. Refer to Air

Conditioning Accumulator
Replacement (Non-HP2).

3. Recharge the A/C system. Refer to

Refrigerant Recovery and
Recharging.

Are the actions complete?

-

Go to Step 14

-

14

1. Record the low and high side

pressures and the I/P outlet air
temperature.

2. Compare the outlet temperatures to

those listed in the A/C System
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 high and low side pressures and
I/P panel outlet temperatures within
specifications?

-

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

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 B

Go to Step 15

Engine
w/Engine
Driven Fan)

15

Operate the system in order to verify the
repair.
Did you find and correct the condition?

-

System OK

Go to
Symptoms -
HVAC
Systems -
Manual
or
Go to
Symptoms -
HVAC
Systems -
Automatic

Step

Action

Yes

No

DEFINITION: The low side pressure is higher than normal and the high side pressure is
lower than normal.

Malfunctioning A/C compressor

Refrigerant under charge

1

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
(A/C) System
Performance
Test (Gas
Engine w/
Electric Cooling
Fan) or Air
Conditioning
(A/C) System
Performance

2008 Chevrolet Silverado 1500

2008 HVAC Heating, Ventilation, and Air Conditioning - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado