2010 HUMMER H3 heating

Instruments and Controls 5-5
Power Outlets
The accessory power outlets can be
used to connect auxiliary electrical
equipment, such as a cellular
phone.
There are two accessory power
outlets located under the climate
control system. There is also one
accessory power outlet located in
the rear cargo area (H3 model only).
Pull down the small cover to access
the accessory power outlet.
Notice:Leaving electrical
equipment on for extended
periods will drain the battery.
Always unplug electrical
equipment when not in use
and do not plug in equipment
that exceeds the maximum
amperage rating of 20 amperes. Certain electrical accessories
may not be compatible with the
accessory power outlet and could
result in blown vehicle or adapter
fuses. If you experience a problem,
see your dealer for additional
information on accessory power
outlets.
Notice:
Adding any electrical
equipment to the vehicle
can damage it or keep other
components from working as
they should. The repairs would
not be covered by the vehicle
warranty. Do not use equipment
exceeding maximum amperage
rating of 20 amperes. Check
with your dealer before adding
electrical equipment.
When adding electrical equipment,
be sure to follow the proper
installation instructions included
with the equipment. Notice:
Improper use of the
power outlet can cause damage
not covered by the vehicle
warranty. Do not hang any type
of accessory or accessory
bracket from the plug because
the power outlets are designed
for accessory power plugs only.
Cigarette Lighter
For vehicles with a lighter, push the
lighter down and it will pop up when
it is ready to be used.
Notice: Holding a cigarette lighter
in while it is heating does not let
the lighter back away from the
heating element when it is hot.
Damage from overheating can
occur to the lighter or heating
element, or a fuse could be
blown. Do not hold a cigarette
lighter in while it is heating.

Instruments and Controls 5-9
Engine Coolant
Temperature Gauge
United StatesCanada
This gauge shows the engine
coolant temperature.
If the gauge pointer is in the shaded
area of the gauge, the engine is
too hot. It means that the engine
coolant has overheated. If the
vehicle has been operating under
normal driving conditions, pull off
the road, stop your vehicle and turn
off the engine as soon as possible.
See Engine Overheating
on
page 10‑22for more information.
Safety Belt Reminders
Driver Safety Belt Reminder
Light
There is a driver safety belt
reminder light on the instrument
panel cluster.
When the engine is started this
light and a chime come on and stay
on for several seconds to remind
drivers to fasten their safety belts.
The light also begins to flash.
This cycle repeats if the driver
remains unbuckled and the vehicle
is moving.
If the driver safety belt is already
buckled, neither the light nor chime
come on.
Passenger Safety Belt
Reminder Light
The passenger safety belt reminder
light is by the passenger airbag
status indicator.
When the engine is started this light
and the chime come on and stay on
for several seconds to remind the
passenger to fasten their safety belt.
The light also begins to flash.
This cycle repeats if the passenger
remains unbuckled and the vehicle
is moving.
If the passenger safety belt is
buckled, neither the chime nor the
light comes on.

Instruments and Controls 5-23
Engine Cooling System
Messages
AC (Air Conditioning) OFF
This message displays when the
engine coolant temperature is too
high and the air conditioning in
the vehicle needs to be turned off.
SeeEngine Overheating
on
page 10‑22and Climate Control
Systemson page 8‑1for more
information. This message displays
along with the ENG HOT message.
ENG (Engine) HOT
This message displays when the
engine coolant temperature is
hot. Check the engine coolant
temperature gauge. See Engine
Coolant Temperature Gauge
on
page 5‑9. Have the vehicle
serviced by your dealer as soon
as possible if you suspect the
engine is overheating. See Engine
Overheating
on page 10‑22for more
information.
Engine Oil Messages
CHANGE OIL
This message displays when the
oil needs to be changed. Check
the oil in the vehicle as soon as
possible and have the vehicle
serviced by your dealer. See Engine
Oil
on page 10‑9and Scheduled
Maintenanceon page 11‑2for
more information. Press and release
the reset stem to acknowledge the
message and clear it from the
display.
OIL
This message displays when the oil
pressure is low. See Engine Oil
Pressure Light
on page 5‑17and
Engine Oilon page 10‑9for more
information.
Engine Power Messages
REDUCED POWER
This message displays when the
vehicle's engine power is reduced.
Reduced engine power can affect
the vehicle's ability to accelerate.
If this message is on, but there
is no reduction in performance,
proceed to your destination.
The performance may be reduced
the next time the vehicle is driven.
The vehicle may be driven at a
reduced speed while this message
is on, but acceleration and speed
may be reduced. Anytime this
message stays on, the vehicle
should be taken to your dealer
for service as soon as possible.
Press and release the reset stem
to acknowledge the message and
clear it from the display.

Climate Controls 8-1
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . 8-1
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . 8-4
Climate Control Systems
The heating, cooling, and ventilation of the vehicle can be controlled with
this system.
A. Temperature Control
B. Fan Control
C. Air Delivery Mode Control
D. Air Conditioning
E. Recirculation
F. Rear Window Defogger9
(Off): Turn the fan control to this
position to turn the fan off. Air still
enters the vehicle and increases
with vehicle speed depending on
the mode and temperature settings.
Turn on the recirculation mode to
stop this airflow.
Temperature Control: Turn
clockwise or counterclockwise
to increase or decrease the
temperature of the air in the vehicle.

Driving and Operating 9-73
Vehicles with an automatic
transmission can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts too
often under heavy loads and/or
hilly conditions. For vehicles with a
manual transmission, it is better not
to use the highest gear.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. For vehicles with manualtransmissions, let the engine run
while parked, preferably on level
ground, with the transmission out of
gear and the parking brake applied,
for a few minutes before turning the
engine off. If the overheat warning
comes on, see
Engine Overheating
on page 10‑22.
Parking on Hills
{WARNING
Parking the vehicle on a hill
with the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet for
vehicles with an automatic
transmission, or into gear
for vehicles with a manual
transmission. Turn the wheels
into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the brake pedal
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park) for vehicles with an
automatic transmission or into
gear for vehicles with a manual
transmission.
5. Release the brake pedal.

9-74 Driving and Operating
Leaving After Parking on a Hill
1. Apply and hold the brake pedalwhile you:
.start the engine,
.shift into a gear, and
.release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See this
manual's Maintenance Schedule
or Index for more information.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See
Engine Overheating
on page 10‑22.
Trailer Towing
Three important considerations
have to do with weight:
.The weight of the trailer.
.The weight of the trailer tongue.
.The total weight on the vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, special
equipment, and the amount of
tongue weight the vehicle can carry
must be considered. See “Weight of
the Trailer Tongue” later in this
section for more information.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment.
The weight of additional optional
equipment, passengers and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.
Use the following chart to determine
how much a vehicle can weigh,
based on the vehicle model and
options.

Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-9
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-12
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-15 Hydraulic Clutch . . . . . . . . . . . . 10-16
Engine Air Cleaner/Filter . . . . 10-17
Cooling System . . . . . . . . . . . . 10-18
Engine Coolant . . . . . . . . . . . . . 10-19
Engine Overheating . . . . . . . . 10-22
Engine Fan . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-29
Rear Axle . . . . . . . . . . . . . . . . . . 10-29
Starter Switch Check . . . . . . . 10-30
Automatic Transmission Shift
Lock Control System
Check . . . . . . . . . . . . . . . . . . . . . 10-30
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-31
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-31
Wiper Blade Replacement . . . . . . . . . . . . . . 10-32
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-33
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-35
Halogen Bulbs . . . . . . . . . . . . . . 10-35
Headlamps . . . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal,Stoplamps, and Back-Up
Lamps (H3) . . . . . . . . . . . . . . . 10-35
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps (H3T) . . . . . . . . . . . . . . 10-36
License Plate Lamp . . . . . . . . 10-37
Replacement Bulbs . . . . . . . . . 10-37
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-38
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-39
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-39

Vehicle Care 10-19
Engine Coolant
The cooling system in the vehicle
is filled with DEX-COOL®engine
coolant. This coolant is designed to
remain in the vehicle for five years
or 240 000 km (150,000 miles),
whichever occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating
on
page 10‑22.
What to Use
{WARNING
Adding only plain water to
the cooling system can be
dangerous. Plain water, or some
other liquid such as alcohol,
can boil before the proper
coolant mixture will. The vehicle's
coolant warning system is set
for the proper coolant mixture.
(Continued)
WARNING (Continued)
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or
others could be burned. Use a
50/50 mixture of clean, drinkable
water and DEX-COOL
®coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
.Gives freezing protection down
to −37°C (−34°F), outside
temperature.
.Gives boiling protection up
to 129°C (265°F), engine
temperature.
.Protects against rust and
corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts.
Notice: If extra inhibitors
and/or additives are used in the
vehicle's cooling system, the
vehicle could be damaged. Use
only the proper mixture of the
engine coolant listed in this
manual for the cooling system.
See Recommended Fluids and
Lubricants
on page 11‑8for more
information.