ECU HUMMER H3 2007 Workshop Manual

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.
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 will have a lot less traction, or
grip, and will 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
may 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.
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If you put things inside your vehicle — like
suitcases, tools, packages, or anything
else — they will 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.
CAUTION: (Continued)
CAUTION: (Continued)

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 250.
Towing
Towing Your Vehicle
Consult your dealer or a professional towing service
if you need to have your disabled vehicle towed.
SeeRoadside Assistance Program on page 454.
If you want to tow your vehicle behind another
vehicle for recreational purposes (such as behind
a motorhome), see “Recreational Vehicle
Towing” following.
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Dinghy Towing
Use the following procedure to tow your vehicle:
1. Shift the transmission to NEUTRAL (N).
2. Turn the engine off, but leave the
ignition in ON.
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
automatic transmission is in PARK (P) or
the manual transmission is in any gear.
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 111for
the proper procedure to select the NEUTRAL
position for your vehicle.
6. Put the transmission in PARK (P) for an
automatic transmission or in FIRST (1) for
a manual transmission.
7. Release the parking brake only after the
vehicle being towed is rmly attached to
the towing vehicle.
8. Turn the ignition off.
After towing, see “Shifting Out of NEUTRAL”
underFull-Time Four-Wheel Drive on page 111.
Dolly Towing
Notice:Dolly towing your vehicle will damage
drivetrain components. Do not dolly tow
your vehicle.
Your vehicle cannot be dolly towed. If you must
tow your vehicle behind another, use the
dinghy towing procedure listed previously.
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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
Automatic Transmission 4.56 4,500 lbs (2 041 kg) 9,500 lbs (4 309 kg)
Manual Transmission 4.56 3,000 lbs (1 364 kg) 8,000 lbs (3 629 kg)
*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.
You can ask your dealer for our trailering
information or advice, or you can write us at
our Customer Assistance Offices. SeeCustomer
Assistance Offices on page 452for more
information.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total
gross weight of your vehicle. The Gross Vehicle
Weight (GVW) includes the curb weight of
the vehicle, any cargo you may carry in it, and
the people who will be riding in the vehicle.If you have a lot of options, equipment, passengers
or cargo in your vehicle, it will reduce the tongue
weight your vehicle can carry, which will also
reduce the trailer weight your vehicle can tow.
If you will tow a trailer, you must add the tongue
load to the GVW because your vehicle will be
carrying that weight, too. SeeLoading Your
Vehicle on page 289for more information about
your vehicle’s maximum load capacity.
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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’ll need more passing distance up ahead when
you’re towing a trailer. Because you’re a good
deal longer, you’ll 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.
Making Turns
Notice:Making very sharp turns while
trailering could cause the trailer to come in
contact with the vehicle. Your vehicle could
be damaged. Avoid making very sharp
turns while trailering.
When you’re turning with a trailer, make wider
turns than normal. Do this so your trailer
won’t strike soft shoulders, curbs, road signs,
trees or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
304

Add coolant mixture at the recovery tank, but be
careful not to spill it.
{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.
Occasionally check the coolant level in the
radiator. For information on how to add coolant to
the radiator, seeCooling System on page 340.
Radiator 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.
SeeEngine Compartment Overview on page 322
for more information on location.
Engine Overheating
A coolant temperature gage is on the instrument
panel. SeeEngine Coolant Temperature Gage
on page 185.
The air conditioning might stop working if the
engine is too hot. This is normal and helps cool
the engine.
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.
CAUTION: (Continued)
338

3. Fill the radiator with the proper DEX-COOL®
coolant mixture, up to the base of the ller
neck. SeeEngine Coolant on page 335
for more information about the proper coolant
mixture.
4. Fill the coolant recovery tank to the
FULL COLD mark.
5. Reinstall the cap on the coolant recovery tank,
but leave the radiator pressure cap off.6. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan.
7. By this time, the coolant level inside the
radiator ller neck might be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.
8. Then replace the pressure cap.
At any time during this procedure if coolant begins
to ow out of the ller neck, reinstall the pressure
cap. Be sure to secure it tightly.
344

Headlamps
To replace a headlamp bulb, do the following:
1. Open the hood. SeeHood Release on
page 321for more information.
2. Reach in and access the headlamp bulb
socket from inside the engine compartment.
3. Turn the bulb socket counterclockwise to
remove it from the headlamp assembly
and pull it straight out.4. Unplug the electrical connector by pushing
the release tab and pulling the bulb
socket out.
5. Replace with a new bulb socket.
6. Reinstall the electrical connector.
7. Reinstall the new bulb socket into the
headlamp assembly and turn it clockwise
to secure.
8. Close the hood.
362

3. Pull the taillamp assembly away from the
vehicle.
4. Turn the bulb socket counterclockwise to
remove it from the taillamp assembly.
5. Holding the socket, pull the old bulb to
release it from the socket.
6. Push the new bulb into the socket until it
clicks.
7. Insert the bulb socket into the taillamp
assembly and turn it clockwise to secure.
8. Reinstall the taillamp assembly by lining up
the locator pins with the retainers in the
vehicle’s body.
9. Reinstall the two screws and tighten.
10. Close the swing-gate.License Plate Lamp
To replace one of these bulbs, do the following:
1. Reach under the bumper for the bulb socket.
2. Remove the two screws holding the license
plate lamp.
3. Pull the license plate lamp away from the
fascia.
364

4. Turn the bulb socket counterclockwise and
pull the bulb straight out of the license plate
lamp assembly.
5. Install the new bulb into the socket.
6. Insert the bulb socket into the license plate
lamp assembly and turn it clockwise to
secure.
7. Replace the license plate lamp assembly and
tighten the two screws.
Replacement Bulbs
Exterior Lamp Bulb Number
Back-up Lamp, Stoplamp,
Taillamp and Turn Signal Lamp3157K
License Plate Lamp 194
Low-Beam and High-Beam
HeadlampH13
For replacement bulbs not listed here, contact
your dealer.
Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected for
wear and cracking. SeeScheduled Maintenance
on page 429for more information.
Replacement blades come in different types and
are removed in different ways. For proper type and
length, seeNormal Maintenance Replacement
Parts on page 442.
365