Hummer H3. Manual — part 1253

A/C Performance Table

Does all the data recorded fall
within the specified ranges of the
A/C performance table?

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

6

Are the low and high side pressures
both greater than the specified
ranges?

-

Go to Air
Conditioning
(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

Ambient

Temperature

Relative

Humidity

Low Side

Service Port

Pressure

High Side

Service Port

Pressure

Maximum Left

Center

Discharge Air

Temperature

13-18°C (55-65°

151-192 kPa

716-1198 kPa

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

F)

0-100%

(22-28 psi)

(104-174 psi)

7°C (43°F)

19-24°C (66-75°

F)

Below 40%

151-248 kPa

(22-36 psi)

888-1391 kPa

(129-202 psi)

8°C (46°F)

Above 40%

158-234 kPa

(23-34 psi)

992-1481 kPa

(144-215 psi)

8°C (46°F)

25-29°C (76-85°

F)

Below 35%

199-275 kPa

(29-40 psi)

1247-1646 kPa

(181-239 psi)

12°C (52°F)

35-50%

199-268 kPa

(29-39 psi)

1302-1667 kPa

(189-242 psi)

12°C (52°F)

Above 50%

192-254 kPa

(28-37 psi)

1329-1708 kPa

(193-248 psi)

12°C (52°F)

30-35°C (86-95°

F)

Below 30%

206-316 kPa

(30-46 psi)

1543-1970 kPa

(224-286 psi)

15°C (59°F)

30-50%

220-303 kPa

(32-44 psi)

1557-1977 kPa

(226-287 psi)

15°C (59°F)

Above 50%

220-289 kPa

(32-42 psi)

1591-1991 kPa

(231-289 psi)

16°C (60°F)

36-41°C (96-105°

F)

Below 20%

275-372 kPa

(40-54 psi)

1887-2321 kPa

(274-337 psi)

20°C (68°F)

20-40%

282-351 kPa

(41-51 psi)

1887-2301 kPa

(274-334 psi)

20°C (68°F)

Above 40%

254-330 kPa

(37-48 psi)

1901-2280 kPa

(276-331 psi)

21°C (69°F)

42-46°C (106-

115°F)

Below 20%

310-406 kPa

(45-59 psi)

2239-2597 kPa

(325-377 psi)

23°C (73°F)

Above 20%

330-431 kPa

(48-60 psi)

2239-2569 kPa

(325-373 psi)

24°C (75°F)

47-49°C (116-

120°F)

Below 30%

372-468 kPa

(54-68 psi)

2521-2859 kPa

(366-415 psi)

27°C (80°F)

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

Fig. 1: A/C System Pressure Zone Classification
Courtesy of GENERAL MOTORS CORP.

AIR CONDITIONING (A/C) DIAGNOSTICS - PRESSURE ZONE A

Air Conditioning (A/C) Diagnostics - Pressure Zone A

Step

Action

Value

Yes

No

DEFINITION: The high and low side pressures may be normal or slightly less than normal.

Air Delivery Concern

Slight Refrigerant Under Charge

Refrigerant Contamination

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

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

2

Refer to the instrument panel outlet
air temperatures recorded during
the A/C system performance test.
Does the discharge air temperature
between the right and left center
instrument panel outlets vary by
more than 1-2°C (2-3°F)?

-

Go to Step 7

Go to Step 3

3

Did the customer mention that the
A/C system output temperatures
are good at first, but then turn
warm during extended drives?

-

Go to Step 4

Go to Step 5

4

Increase engine speed to 2,000
RPM.
During extended operation of the
A/C system, does the low side
pressure decrease, possibly
accompanied by heavy frost on the
liquid line between the expansion
device and the evaporator?

-

Go to Air
Conditioning
(A/C)
Diagnostics -
Pressure Zone
D

Go to Step 5

5

1. Refer to the pressures

recorded during the A/C
system performance test.

2. Inspect for the following

conditions:

The high side pressure is
slightly greater than the
specified pressure
ranges but still within
Zone A on the A/C
Pressure-Zone
Classification Chart in
the A/C System
Performance Test. Refer

CAUTION:

Refer to Moving Parts
and Hot Surfaces
Caution .

-

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3