2008 HUMMER H2 ECU

Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency supplies
in your vehicle.
Include an ice scraper, a small brush or broom, a
supply of windshield washer uid, a rag, some winter
outer clothing, a small shovel, a ashlight, a red
cloth, and a couple of reective warning triangles.
And, if you will be driving under severe conditions,
include a small bag of sand, a piece of old carpet,
or a couple of burlap bags to help provide traction.
Be sure you properly secure these items in your vehicle.
Also seeTires on page 5-55.
Driving on Snow or Ice
Most of the time, those places where the tires meet the
road probably have good traction.
However, if there is snow or ice between the tires and
the road, you can have a very slippery situation.
You have a lot less traction, or grip, and need to be
very careful.What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on. But wet ice
can be even more trouble because it can offer the least
traction of all. You can get wet ice when it is about
freezing, 32°F (0°C), and freezing rain begins to fall.
Try to avoid driving on wet ice until salt and sand crews
can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
4-36

If you put things inside your vehicle — like
suitcases, tools, packages, or anything else — they
go as fast as the vehicle goes. If you have to stop or
turn quickly, or if there is a crash, they will keep
going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.There is also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving” underOff-Road
Driving on page 4-13.
Add-On Equipment
When you carry removable items, you may need
to put a limit on how many people you can
carry inside your vehicle. Be sure to weigh your
vehicle before you buy and install the new
equipment.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.
The Cargo Weight Rating (CWR) is the maximum
weight of the load your vehicle can carry.
It does not 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
vehicle’s CWR.
4-50

Dinghy Towing
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition in
ACCESSORY.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the
tow vehicle.
{CAUTION:
Shifting a full-time four-wheel-drive vehicle’s
transfer case into NEUTRAL can cause your
vehicle to roll even if the transmission is in
PARK (P). You or others could be injured.
Make sure the parking brake is rmly set
before you shift the transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Full-Time Four-Wheel Drive on page 2-36for
the proper procedure to select the NEUTRAL
position for your vehicle.6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle. You can use your vehicle’s front mounted
receiver with the proper accessories to tow it.
See “Front Mounted Receiver” underIf Your Vehicle
is Stuck in Sand, Mud, Ice, or Snow on page 4-39.
7. Turn the ignition to ACCESSORY.
8. Disconnect the battery if you are going to tow for
long distances or long periods of time.
When towing your vehicle for extended periods of time,
start your vehicle as often as possible to prevent
battery drain. This should only be done when the tow
vehicle is parked.Dolly Towing
Your vehicle cannot be dolly towed. If you must tow
your vehicle behind another, use the dinghy towing
procedure listed previously.
Notice:Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow your
vehicle.
4-52

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For example,
speed, altitude, road grades, outside temperature and
how much your vehicle is used to pull a trailer are all
important. It can also depend on any special equipment
that you have on your vehicle, and the amount of tongue
weight the vehicle can carry. 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 your
vehicle can weigh, based upon your vehicle model and
options.
Engine Axle Ratio Maximum Trailer Weight **GCWR
6.2L V8 (SUV) 3.73 8,200 lbs (3 720 kg) 15,000 lbs (6 804 kg)
6.2L V8 (SUT)* 3.73 8,200 lbs (3 720 kg) 15,000 lbs (6 804 kg)
*Sport utility truck (SUT) models are neither designed nor intended to tow 5th wheel or gooseneck trailers.
**The Gross Combination Weight Rating (GCWR) in the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be
exceeded.
Ask your dealer/retailer for our trailering information or
advice, or write us at our Customer Assistance Offices.
SeeCustomer Assistance Offices on page 7-5for
more information.
4-58

Driving with a Trailer
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get to
know your rig. Acquaint yourself with the feel of handling
and braking with the added weight of the trailer. And
always keep in mind that the vehicle you are driving is
now a good deal longer and not nearly as responsive as
your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You will need more passing distance up ahead when
you’re towing a trailer. Because you are a good deal
longer, you will need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
4-63

Checking Coolant
The coolant surge tank is
located in the engine
compartment on the
passenger’s side of the
vehicle. SeeEngine
Compartment Overview on
page 5-12for more
information on location.
{CAUTION:
Turning the surge tank pressure cap when the
engine and radiator are hot can allow steam
and scalding liquids to blow out and burn you
badly. Never turn the surge tank pressure
cap — even a little — when the engine and
radiator are hot.
The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at the
FULL COLD mark.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may occur.
Be sure the cap is properly and tightly secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
5-26

Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for wear
and cracking. SeeScheduled Maintenance on page 6-4
for more information.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
seeMaintenance Replacement Parts on page 6-14.
To replace the windshield wiper blade assembly do the
following:
1. Lift the wiper arm away from the windshield.2. Push the release lever (B) to disengage the hook
and push the wiper arm (A) out of the blade (C).
3. Push the new wiper blade securely on the wiper
arm until you hear the release lever click into
place.
5-54

{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after time. The wheel could
come off and cause an accident. When
you change a wheel, remove any rust or
dirt from places where the wheel attaches
to the vehicle. In an emergency, you can
use a cloth or a paper towel to do this;
but be sure to use a scraper or wire brush
later, if needed, to get all the rust or dirt
off. SeeChanging a Flat Tire on page 5-78.
Make sure the spare tire is stored securely. Push,
pull, and then try to rotate or turn the tire. If it
moves, tighten the cable. SeeStoring a Flat or
Spare Tire and Tools (SUT) on page 5-94or
Storing a Flat or Spare Tire and Tools (SUV) on
page 5-96.
When It Is Time for New Tires
Various factors, such as maintenance, temperatures,
driving speeds, vehicle loading, and road conditions,
inuence when you need new tires.
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which appear
when your tires have
only 1/16 inch (1.6 mm) or
less of tread remaining.
Some commercial
truck tires may not have
treadwear indicators.
5-69