Hummer H3. Manual — part 1252

To prevent false diagnosis, thoroughly clean any residual dye from the service port with a
rag and the approved fluorescent dye cleaner J 43872 .

Halogen Leak Detector

Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in
order to perform a leak test. Refer to Refrigerant Recovery and Recharging for recharging the
A/C system.

Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.

Follow the instructions supplied with the J 39400-A .

AIR CONDITIONING (A/C) SYSTEM PERFORMANCE TEST

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

7.39 ml (0.25 oz.) charge.

CAUTION: Do not operate the detector in a combustible atmosphere

since its sensor operates at high temperatures or personal
injury and/or damage to the equipment may result.

IMPORTANT: Halogen leak detectors are sensitive to the following items:

Windshield washing solutions

Many solvents and cleaners

Some adhesives used in the vehicle

IMPORTANT: Follow a continuous path in order to ensure that you will not miss

any possible leaks. Test all areas of the system for leaks.

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

The numbers below refer to the step numbers on the diagnostic table.

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 temperatures.

Air Conditioning (A/C) System Performance Test

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 Air Conditioning
Service Center. 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 side and high side
pressures within the specified
value?

More than

16°C (60°F)

- 345 kPa

(50 psi)

More than

24°C (75°F)

- 483 kPa

(70 psi)

More than

33°C (90°F)

- 690 kPa

(100 psi)

Go to Step 2

Go to Leak
Testing

IMPORTANT:

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

2

1. Close the vehicle doors and

windows.

2. Open the driver door window

12.7-15.2 cm (5-6 in).

3. Select the following HVAC

control settings:

The A/C is ON.

The coldest temperature
setting

The maximum blower
speed

Recirculation mode

The I/P panel outlet
mode

All I/P panel outlets are
OPEN

4. Install the temperature probes

of the J 43600 in the left and
right center panel air outlets.
See Special Tools.

5. Apply the parking brake.

6. Place the

transaxle/transmission in one
of the following positions:

PARK (Automatic)

NEUTRAL (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

Record the relative humidity
and the ambient air temperature
at the time of the test.

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2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3

Unusual noises

10. Print the following

information:

The panel outlet air
temperatures

The low side pressure

The high side pressure

11. Compare the low and high

side pressures and the panel
output temperatures to the
A/C performance table
below.

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

IMPORTANT:

Press the RESET button, before
using the print function of the J
43600 . See Special Tools.

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 A/C
performance table.

-

2007 Hummer H3

2007 HVAC Heating, Ventilation and Air Conditioning - H3