2008 HUMMER H3 Towing

Trailer Brake Control Wiring Harness
The trailer brake control wiring harness is located
under the instrument panel to the right of the steering
column. The wires are taped to the harness that goes
to the courtesy light under the instrument panel.
The harness will contain the following wires:
Red Wire: AUX B+
Black Wire: Ground
Light Blue Wire: Brake Signal
Dark Blue Wire: Trailer Brakes
Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR). CWR is the maximum weight
of the load your vehicle can carry. It doesn’t include the
weight of the people inside, but you can gure about
150 lbs. (68 kg) for each seat. The total cargo load
must not be more than your vehicles CWR.
Weigh your vehicle with your trailer attached, so that
you won’t go over the GVWR or GAWR. If you are using
a weight-distributing hitch, weigh the vehicle without
the spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information seeTowing a Trailer on page 4-50.
4-62

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can burn
you badly, even if you just open the hood. Stay
away from the engine if you see or hear steam
coming from it. Just turn it off and get
everyone away from the vehicle until it cools
down. Wait until there is no sign of steam or
coolant before you open the hood.
If you keep driving when your engine is
overheated, the liquids in it can catch re. You
or others could be badly burned. Stop your
engine if it overheats, and get out of the
vehicle until the engine is cool.
Notice:If your engine catches re because you
keep driving with no coolant, your vehicle can
be badly damaged. The costly repairs would not be
covered by your warranty.
If No Steam Is Coming From Your
Engine
If you get an engine overheat warning but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. See “Driving on Grades” under
Towing a Trailer on page 4-50.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in NEUTRAL
while stopped. If it is safe to do so, pull off the
road, shift to PARK (P) or NEUTRAL and let the
engine idle.
2. Turn off the air conditioning.
3. Turn on your heater to full hot at the highest fan
speed and open the windows as necessary.
5-30

Engine Fan Noise
This vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing and/or high outside temperatures,
the fan speed increases when the clutch engages.
So you may hear an increase in fan noise. This
is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
Power Steering Fluid
SeeEngine Compartment
Overview on page 5-12for
reservoir location.
When to Check Power Steering Fluid
It is not necessary to regularly check power steering uid
unless you suspect there is a leak in the system or
you hear an unusual noise. A uid loss in this system
could indicate a problem. Have the system inspected
and repaired.
How to Check Power Steering Fluid
1. Turn the key off and let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a
clean rag.
5-36

(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-52 and Windshield, Backglass, and Wiper
Blades on page 5-97 for more information.
(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-69.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer swing-gate handle pivot
points, rear door detent link, roller mechanism,
swing-gate handle pivot points, latch bolt, fuel door
hinge, locks, and folding seat hardware. More frequent
lubrication may be required when exposed to a
corrosive environment. Applying silicone grease on
weatherstrips with a clean cloth will make them
last longer, seal better, and not stick or squeak.(g)Check vent hose at transfer case for kinks and
proper installation.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-27
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
6-8

HUMMER Technician Roadside Service
(U.S. only)
HUMMER’s exceptional Roadside Service is more
than an auto club or towing service. It provides every
HUMMER owner in the United States with the
advantage of contacting a HUMMER advisor and, where
available, a HUMMER trained dealer technician who
can provide on-site service.
A dealer technician will travel to your location generally
within a 30 mile radius of a participating HUMMER
dealership. If beyond this radius, we will arrange to have
your car towed to the nearest HUMMER dealership.
Each technician travels with a specially equipped service
vehicle complete with the necessary HUMMER parts
and tools required to handle most roadside repairs.
Calling for Assistance
For prompt and efficient assistance when calling, please
provide the following to the Roadside Assistance
Representative:
Your name, home address, and home telephone
number
Telephone number of your location
Location of the vehicle
Model, year, color, and license plate number of the
vehicle
Odometer reading, Vehicle Identication
Number (VIN), and delivery date of the vehicle
Description of the problem
Towing and Road Service Exclusions
Specically excluded from Roadside Service coverage
are towing or services for vehicles operated on a
non-public roadway or highway, nes, impound towing
caused by a violation of local, Municipal, State,
Provincial or Federal law, and mounting, dismounting or
changing of snow tires, chains, or other traction
devices.
Roadside Assistance is not part of or included in the
coverage provided by the New Vehicle Limited Warranty.
HUMMER and General Motors of Canada Limited
reserve the right to make any changes or discontinue
the Roadside Assistance program at any time without
notication.
7-8

Insuring Your Vehicle
Protect your investment in your GM vehicle with
comprehensive and collision insurance coverage. There
are signicant differences in the quality of coverage
afforded by various insurance policy terms. Many
insurance policies provide reduced protection to your
GM vehicle by limiting compensation for damage repairs
by using aftermarket collision parts. Some insurance
companies will not specify aftermarket collision
parts. When purchasing insurance, we recommend that
you assure your vehicle will be repaired with GM
original equipment collision parts. If such insurance
coverage is not available from your current insurance
carrier, consider switching to another insurance carrier.
If your vehicle is leased, the leasing company may
require you to have insurance that assures repairs with
Genuine GM Original Equipment Manufacturer (OEM)
parts or Genuine Manufacturer replacement parts. Read
your lease carefully, as you may be charged at the
end of your lease for poor quality repairs.
If a Crash Occurs
Here is what to do if you are involved in a crash.
Try to relax and then check to make sure you are
all right. If you are uninjured, make sure that no
one else in your vehicle, or the other vehicle,
is injured.
If there has been an injury, call emergency services
for help. Do not leave the scene of a crash until all
matters have been taken care of. Move your
vehicle only if its position puts you in danger or you
are instructed to move it by a police officer.
Give only the necessary and requested information
to police and other parties involved in the crash.
Do not discuss your personal condition, mental
frame of mind, or anything unrelated to the crash.
This will help guard against post-crash legal action.
If you need roadside assistance, call GM Roadside
Assistance. SeeRoadside Assistance Program on
page 7-6for more information.
If your vehicle cannot be driven, know where the
towing service will be taking it. Get a card from
the tow truck operator or write down the driver’s
name, the service’s name, and the phone number.
7-12

Privacy..........................................................7-16
Event Data Recorders..................................7-17
Navigation System.......................................7-18
OnStar.......................................................7-18
Radio Frequency Identication.......................7-18
Programmable Automatic Door Locks.................. 2-8
R
Radiator Pressure Cap....................................5-29
Radio Frequency Identication (RFID), Privacy....7-18
Radios..........................................................3-48
Radio(s)........................................................3-49
Radios
Navigation/Radio System, see Navigation
Manual...................................................3-61
Reception...................................................3-61
Setting the Time..........................................3-48
Theft-Deterrent............................................3-61
Reading Lamps..............................................3-20
Rear Axle......................................................5-45
Locking........................................................ 4-6
Rear Door Security Locks.................................. 2-9
Rear Storage Area..........................................2-59
Rear Vision Camera........................................2-44
Rear Windshield Washer/Wiper.........................3-11
Rearview Mirror, Automatic Dimming with
Compass and Temperature Display................2-41Rearview Mirror, Automatic Dimming with
OnStar
®, Compass and Temperature Display.....2-38
Reclining Seatbacks.......................................... 1-4
Recommended Fluids and Lubricants.................6-12
Recovery Loops..............................................4-40
Recreational Vehicle Towing.............................4-48
Remote Keyless Entry (RKE) System.................. 2-4
Remote Keyless Entry (RKE) System, Operation . . . 2-5
Removing the Flat Tire and Installing the
Spare Tire..................................................5-83
Removing the Spare Tire and Tools...................5-81
Replacement Bulbs.........................................5-52
Replacement Parts, Maintenance......................6-14
Reporting Safety Defects
Canadian Government..................................7-15
General Motors...........................................7-15
United States Government............................7-14
Restraint System Check
Checking the Restraint Systems....................1-69
Replacing Restraint System Parts
After a Crash..........................................1-70
Retained Accessory Power (RAP)......................2-20
Roadside
Assistance Program....................................... 7-6
Rocking Your Vehicle to Get it Out....................4-40
Routing, Engine Drive Belt...............................6-15
Running the Engine While Parked.....................2-37
10

Towing
Recreational Vehicle.....................................4-48
Towing a Trailer..........................................4-50
Your Vehicle...............................................4-48
Traction
Control System (TCS).................................... 4-5
Off Light.....................................................3-34
StabiliTrak
®System....................................... 4-7
Trailer
Recommendations.......................................4-62
Transmission
Fluid, Automatic...........................................5-21
Fluid, Manual..............................................5-24
Up-Shift Light..............................................3-32
Transmission Operation, Automatic....................2-23
Transmission Operation, Manual........................2-26
Trip Odometer................................................3-27
Turn and Lane-Change Signals.......................... 3-8
Turn Signal/Multifunction Lever........................... 3-7
U
Uniform Tire Quality Grading............................5-74
Universal Home Remote System.......................2-51
Operation...................................................2-52
Up-Shift Light.................................................3-32
Using this Manual............................................... iii
V
Vehicle
Control........................................................ 4-3
Damage Warnings........................................... iv
Loading......................................................4-42
Parking Your...............................................2-35
Symbols......................................................... iv
Vehicle Data Recording and Privacy..................7-16
Vehicle Identication
Number (VIN)............................................5-100
Service Parts Identication Label..................5-101
Ventilation Adjustment......................................3-24
Visors...........................................................2-13
13