Hummer H2. Manual — part 710

Switches of the Inside Rearview Mirror with the Automatic Day-Night Feature, Compass/Temperature Display without
OnStar(R)

The inside rearview mirror has 2 switches that perform the following functions:

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The TEMP switch is used to turn the compass/temperature display ON or OFF, it is also used to enable or
disable the automatic day-night feature of the mirror. With the ignition in the ON position, depress the
TEMP switch to enable the compass/temperature display. Depress the TEMP switch again to disable the
compass/temperature display. The TEMP switch can be held for 4 seconds in order to change the display
from Fahrenheit (°F) to Celsius (°C), or from Celsius (°C) to Fahrenheit (°F). Depress the TEMP switch
until the green indicator illuminates on the mirror. This indicates that the automatic day-night feature is
enabled. To disable the automatic day-night feature of the mirror, depress the TEMP switch until the
green indicator turns OFF.

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The COMP switch is used to turn the compass/temperature display ON or OFF. With the ignition in the
ON position, depress the COMP switch to turn the compass/temperature display ON. Depress the COMP
switch again to turn the compass/temperature display OFF. The COMP switch is also used to place the
compass into a calibration or zone mode. For more information, refer to Compass Calibration and
Variance Procedure .

Switches of the Inside Rearview Mirror with the Automatic Day-Night Feature with Compass and OnStar(R)

The inside rearview mirror has 4 switches that perform the following functions:

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The ON/OFF switch located at the left side of the mirror performs the following functions:

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To enable or disable the automatic day-night feature of the mirror - With the ignition in the ON
position, depress and hold the ON/OFF switch for 4 seconds to enable the automatic day-night
feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night
feature is enabled. To disable the automatic day-night feature of the mirror, depress and hold the
ON/OFF switch for 4 seconds.

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To turn the compass ON and OFF - With the ignition in the ON position, depress the ON/OFF
switch to turn the compass ON. Depress the ON/OFF switch again to turn the compass OFF. The
ON/OFF switch is also used to place the compass into a calibration or zone mode. For more
information, refer to Compass Calibration and Variance Procedure .

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The 3 switches on the right side of the mirror are for OnStar(R) operation. For more information, refer to
OnStar Description and Operation in Cellular Communication.

Switches of the Inside Rearview Mirror with the Automatic Day-Night Feature, Compass/Temperature Display with
OnStar(R)

The inside rearview mirror has 4 switches that perform the following functions:

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The ON/OFF switch located at the left side of the mirror performs the following functions:

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To enable or disable the automatic day-night feature of the mirror-With the ignition in the ON
position, depress and hold the ON/OFF switch for 6 seconds to enable the automatic day-night
feature of the mirror. A green indicator will illuminate on the mirror when the automatic day-night
feature is enabled. To disable the automatic day-night feature of the mirror, depress and hold the

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

ON/OFF switch for 6 seconds.

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To turn the compass/temperature display ON and OFF-With the ignition in the ON position,
depress the ON/OFF switch to turn the compass/temperature display ON. Depress the ON/OFF
switch again to turn the compass/temperature display OFF. The ON/OFF switch can be held for 4
seconds in order to change the display from Fahrenheit (°F) to Celsius (°C), or from Celsius (°C) to
Fahrenheit (°F). The ON/OFF switch is also used to place the compass into a calibration or zone
mode. For more information, refer to Compass Calibration and Variance Procedure .

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The 3 switches on the right side of the mirror are for OnStar(R) operation. For more information, refer to
OnStar Description and Operation in Cellular Communication.

COMPASS CALIBRATION AND VARIANCE PROCEDURE

Compass Calibration

Before calibrating the compass, drive the vehicle to an open area that is magnetically clean or free of large
metallic objects such as high tension power lines or large steel buildings. Verify there are no magnetized roof
antennas, magnets on or hanging from the mirror, or any other magnetized objects on the inside or outside of
the vehicle close to the mirror.

1. Start the engine.

2. Press and hold the switch for the compass, which may be depicted as COMP, COMPASS, or on/off

(w/UE1) depending on the type of mirror on the vehicle, until the letter "C" or "CAL" is displayed.

3. Drive the vehicle in circles at a speed of less than 8 km/h (5 mph) until the "C" or "CAL" is replaced by a

proper vehicle heading. The calibration procedure is now complete.

Compass Magnetic Variation Adjustment

Magnetic variation adjustments are required when the compass displays a constant error in heading. Variation is
the difference between magnetic north and true north due to geographical location.

IMPORTANT: Before calibrating the compass, make sure the mirror has the correct

zone number. Refer to Compass Magnetic Variation Adjustment.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

Fig. 45: World Magnetic Variation Map
Courtesy of GENERAL MOTORS CORP.

1. Locate your current geographic location on the World Magnetic Variation Map.

2. Turn ON the ignition, with the engine OFF.

3. Press and hold the switch for the compass, which may be depicted as COMP, COMPASS, or on/off

(w/UE1) depending on the type of mirror on the vehicle, until a zone number appears on the compass
display.

4. Depress the switch for the compass to select the desired zone number.

5. Wait 5 seconds. The display will return to a compass heading. The variance procedure is now complete.

6. Calibrate the compass. Refer to Compass Calibration mentioned above.

REAR WINDOW DEFOGGER DESCRIPTION AND OPERATION

Rear Window Defogger System Components

The rear window defogger system consist of the following components:

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HVAC control module

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Body control module (BCM)

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DEFOG relay

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Rear window defogger grid

Rear Window Defogger Operation

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2

Battery positive voltage is supplied through the RR DEFOG fuse, in the underhood fuseblock, to the DEFOG
relay switched input. When you turn ON the ignition, ignition voltage is supplied through the SEO IGN fuse, in
the underhood fuseblock, to the DEFOG relay coil. When you depress the rear window defogger switch. The
HVAC control module illuminates the rear window defogger indicator and sends a class 2 message to the BCM
to enable the rear window defogger system. The BCM energizes the DEFOG relay by grounding the control
circuit of the relay. This allows battery positive voltage from the relay switched input through the switch
contacts and out the relay switched output to the rear window defogger grid. Ground for the rear window
defogger grid is provided by G301.

When you turn ON the ignition and press the rear window defogger switch, the defogger cycle lasts 10 minutes.
Further operation results in additional 10 minute defogger cycles.

STATIONARY WINDOW DESCRIPTION

Most stationary windows, specifically windshields, are retained to the body with urethane adhesive which
adheres the window to the body, increasing structural integrity. The reinstallation of the windows with urethane
adhesive requires complete replacement of the urethane adhesive bead, and is know as the Full Cut Method.

FULL-CUT METHOD DESCRIPTION

Use only the full cut method also know as in the field as Full Strip Method when installing windows.

This method includes the following:

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The replacement of a majority of the urethane adhesive bead remove all but approximately 2 mm (3/64
in) of the existing bead of urethane adhesive from the pinch-weld flange.

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Applying pinch-weld primer to any exposed painted areas on the pinch-weld flange.

No mounds or loose pieces of urethane adhesive should remain on the pinch-weld flange. Do not remove all
traces of urethane adhesive.

IMPORTANT:

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If corrosion of the pinch-weld flange is present, or if sheet metal repairs or
replacements are required, refinish the pinch-weld flange in order to
present a clean, primer-only surface.

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If paint repairs are required, mask the flange bonding area, prior to
applying the color coat, in order to provide a clean, primer-only surface.

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Appropriate materials for these primer applications are typically 2
component catalyzed products. Use materials such as BASF DE15(R),
DuPont 2610(R), Sherwin-Williams PSE 4600 and NP70(R) and Martin-
Semour 5120,5130(R), PPG DP90LF SPIES/ HECKER 3688/8590 -
3688/5150 - 4070/5090 STANDOX 11158/13320 - 14653/14980 products are
approved for this application. Follow the manufacturer's directions for the
mix, the application, and the drying times.

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After repairing the opening as indicated, shake the pinch-weld primer
black #3 well. Using a new dauber, apply the primer to the primed surface

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Stationary Windows - Hummer H2