2008 HUMMER H3 heater

If a child restraint has been installed and the on
indicator is lit, turn the vehicle off. Remove the child
restraint from the vehicle and reinstall the child restraint.
If, after reinstalling the child restraint and restarting
the vehicle, the on indicator is still lit, check to make
sure that the vehicle’s seatback is not pressing the child
restraint into the seat cushion. If this happens, slightly
recline the vehicle’s seatback and adjust the seat
cushion if possible. Also make sure the child restraint is
not trapped under the vehicle head restraint. If this
happens, adjust the head restraint.
Remove any additional material from the seat such
as blankets, cushions, seat covers, seat heaters or
seat massagers before reinstalling or securing the
child restraint.
If the on indicator is still lit, secure the child in the
child restraint in a rear seat position in the vehicle and
check with your dealer/retailer.
To remove the child restraint, unbuckle the vehicle’s
safety belt and let it go back all the way.Airbag System
Your vehicle has the following airbags:
A frontal airbag for the driver.
A frontal airbag for the right front passenger.
A roof-rail airbag for the driver and the passenger
seated directly behind the driver.
A roof-rail airbag for the right front passenger and
the passenger seated directly behind the right
front passenger.
All of the airbags in your vehicle will have the word
AIRBAG embossed in the trim or on an attached label
near the deployment opening.
For frontal airbags, the word AIRBAG will appear on the
middle part of the steering wheel for the driver and
on the instrument panel for the right front passenger.
With roof-rail airbags, the word AIRBAG will appear
along the headliner or trim.
Airbags are designed to supplement the protection
provided by safety belts. Even though today’s airbags
are also designed to help reduce the risk of injury
from the force of an inating bag, all airbags must inate
very quickly to do their job.
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Remove any additional material from the seat such
as blankets, cushions, seat covers, seat heaters,
or seat massagers before reinstalling or securing the
child restraint.
If the on indicator is still lit, secure the child in the child
restraint in a rear seat position in the vehicle, and
check with your dealer/retailer.
The passenger sensing system is designed to enable
(may inate) the right front passenger’s frontal
airbag anytime the system senses that a person of
adult size is sitting properly in the right front passenger’s
seat. When the passenger sensing system has
allowed the airbag to be enabled, the on indicator will
light and stay lit to remind you that the airbag is active.
For some children who have outgrown child restraints
and for very small adults, the passenger sensing system
may or may not turn off the right front passenger’s
frontal airbag, depending upon the person’s seatingposture and body build. Everyone in your vehicle who
has outgrown child restraints should wear a safety
belt properly — whether or not there is an airbag
for that person.
If a person of adult-size is sitting in the right front
passenger’s seat, but the off indicator is lit, it could be
because that person is not sitting properly in the seat.
If this happens, turn the vehicle off, remove any
additional material from the seat, such as blankets,
cushions, seat covers, seat heaters or seat massagers
and ask the person to place the seatback in the fully
upright position, then sit upright in the seat, centered on
the seat cushion, with the person’s legs comfortably
extended. Restart the vehicle and have the person
remain in this position for two to three minutes.
This will allow the system to detect that person and
then enable the right front passenger’s frontal airbag.
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A thick layer of additional material, such as a blanket
or cushion, or aftermarket equipment such as seat
covers, seat heaters, and seat massagers can affect
how well the passenger sensing system operates.
We recommend that you not use seat covers or other
aftermarket equipment other than any that GM has
approved for your specic vehicle. SeeAdding
Equipment to Your Airbag-Equipped Vehicle on
page 1-68for more information about modications
that can affect how the system operates.
{CAUTION:
Stowing of articles under the passenger’s
seat or between the passenger’s seat cushion
and seatback may interfere with the proper
operation of the passenger sensing system.
Servicing Your Airbag-Equipped
Vehicle
Airbags affect how your vehicle should be serviced.
There are parts of the airbag system in several places
around your vehicle. Your dealer/retailer and the service
manual have information about servicing your vehicle
and the airbag system. To purchase a service manual,
seeService Publications Ordering Information on
page 7-15.
{CAUTION:
For up to 10 seconds after the ignition is
turned off and the battery is disconnected,
an airbag can still inate during improper
service. You can be injured if you are close
to an airbag when it inates. Avoid yellow
connectors. They are probably part of the
airbag system. Be sure to follow proper
service procedures, and make sure the person
performing work for you is qualied to do so.
1-67

Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may keep the airbag system from
working properly. Changing or moving any parts of
the front seats, safety belts, the airbag sensing and
diagnostic module, steering wheel, instrument panel,
roof-rail airbag modules, ceiling headliner or pillar
garnish trim, overhead console, front sensors, side
impact sensors, rollover sensor module, or airbag
wiring can affect the operation of the airbag system.
In addition, your vehicle has a passenger sensing
system for the right front passenger’s position, which
includes sensors that are part of the passenger’s
seat. The passenger sensing system may not
operate properly if the original seat trim is replaced
with non-GM covers, upholstery or trim, or with GM
covers, upholstery or trim designed for a different
vehicle. Any object, such as an aftermarket seat
heater or a comfort enhancing pad or device,
installed under or on top of the seat fabric, couldalso interfere with the operation of the passenger
sensing system. This could either prevent proper
deployment of the passenger airbag(s) or prevent
the passenger sensing system from properly turning
off the passenger airbag(s). SeePassenger Sensing
System on page 1-62.
If you have any questions about this, you should
contact Customer Assistance before you modify
your vehicle. The phone numbers and addresses for
Customer Assistance are in Step Two of the
Customer Satisfaction Procedure in this manual.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-73
for additional important information.
Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag sensors,
sensing and diagnostic module and airbag wiring.
1-68

Keys...............................................................2-3
Remote Keyless Entry (RKE) System................2-4
Remote Keyless Entry (RKE) System
Operation...................................................2-5
Doors and Locks.............................................2-7
Door Locks....................................................2-7
Power Door Locks..........................................2-8
Programmable Automatic Door Locks................2-8
Rear Door Security Locks................................2-9
Lockout Protection..........................................2-9
Swing-gate..................................................2-10
Windows........................................................2-11
Power Windows............................................2-12
Sun Visors...................................................2-13
Theft-Deterrent Systems..................................2-14
Content Theft-Deterrent.................................2-14
Passlock
®(U. S. Only)..................................2-15
PASS-Key®III+............................................2-16
PASS-Key®III+ Operation (Canada Only).........2-16Starting and Operating Your Vehicle................2-18
New Vehicle Break-In....................................2-18
Ignition Positions..........................................2-18
Retained Accessory Power (RAP)...................2-20
Starting the Engine.......................................2-20
Engine Coolant Heater..................................2-22
Automatic Transmission Operation...................2-23
Manual Transmission Operation......................2-26
Full-Time Four-Wheel Drive............................2-27
Parking Brake..............................................2-32
Shifting Into PARK (P)
(Automatic Transmission)............................2-33
Shifting Out of PARK (P)
(Automatic Transmission)............................2-35
Parking Your Vehicle (Manual Transmission).....2-35
Parking Over Things That Burn.......................2-36
Engine Exhaust............................................2-36
Running the Engine While Parked...................2-37
Section 2 Features and Controls
2-1

Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0° F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located in the engine compartment
behind the underhood fuse block on the driver’s
side of the vehicle.
3. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.
How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead
of trying to list everything here, we ask that you contact
your dealer/retailer in the area where you will be
parking your vehicle. The dealer/retailer can give you
the best advice for that particular area.
2-22

You can run the engine to keep warm, but be careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You cannot see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking the exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.
Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little faster
than just idle. That is, push the accelerator slightly. This
uses less fuel for the heat that you get and it keeps the
battery charged. You will need a well-charged battery to
restart the vehicle, and possibly for signaling later on with
the headlamps. Let the heater run for a while.
4-38

How to Check and Add Fluid
The proper uid should be added if the level does not
reach the bottom of the diaphragm when it is in place in
the reservoir. See the instructions on the reservoir cap.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-29.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-27