2007 HUMMER H3 Owners Manual

Engine Coolant Heater
Your vehicle may have this feature.
In very cold weather, 0°F (–18°C) or colder, the
engine coolant heater can help. You will get easier
starting and better fuel economy during engine
warm-up. Usually, the coolant heater should be
plugged in a minimum of four hours prior to starting
your vehicle. At temperatures above 32°F (0°C),
use of the coolant heater is not required. Your
vehicle may also have an internal thermostat in the
plug end of the cord. This will prevent operation of
the engine coolant heater when the temperature is
at or above 0F (−18C) as noted on the cord.
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 in the area
where you will be parking your vehicle. The dealer
can give you the best advice for that particular area.
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Automatic Transmission Operation
The automatic transmission has a shift lever on
the console.
It features an electronic shift position indicator
within the instrument cluster. This display must be
powered anytime the shift lever is capable of
being moved out of PARK (P). This means that if
your key is turned off, but not in LOCK, there
will be a small current drain on your battery which
could discharge your battery over a period of
time. If you need to leave your key in the ignition
but not in LOCK for an extended period, it is
recommended that you disconnect the battery
cable from the battery to prevent discharging your
battery.
There are several different positions for your shift
lever.PARK (P):This position locks your rear wheels.
It is the best position to use when you start the
engine because your vehicle cannot move easily.
{CAUTION:
It is dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P)
with the parking brake rmly set. Your
vehicle can roll.
Do not leave your vehicle when the engine
is running unless you have to. If you have
left the engine running, the vehicle can
move suddenly. You or others could be
injured. To be sure your vehicle will not
move, even when you are on fairly level
ground, always set your parking brake and
move the shift lever to PARK (P).
SeeShifting Into Park (P) (Automatic
Transmission) on page 117. If you are
pulling a trailer, seeTowing a Trailer on
page 297.
106

Make sure the shift lever is fully in PARK (P)
before starting the engine. Your vehicle has an
automatic transmission shift lock control system.
You must fully apply your regular brakes rst
and then press the shift lever button before you
can shift from PARK (P) when the ignition key is in
ON. If you cannot shift out of PARK (P), ease
pressure on the shift lever and push the shift lever
all the way into PARK (P) as you maintain
brake application. Then press the shift lever button
and move the shift lever into another gear. See
Shifting Out of Park (P) (Automatic Transmission)
on page 119
REVERSE (R):Use this gear to back up.
Notice:Shifting to REVERSE (R) while your
vehicle is moving forward could damage
the transmission. The repairs would not be
covered by your warranty. Shift to
REVERSE (R) only after your vehicle is
stopped.
To rock your vehicle back and forth to get out of
snow, ice, or sand without damaging your
transmission, seeIf Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow on page 286.NEUTRAL (N):In this position, your engine does
not connect with the wheels. To restart when
you are already moving, use NEUTRAL (N) only.
{CAUTION:
Shifting into a drive gear while your
engine is running at high speed is
dangerous. Unless your foot is rmly on
the brake pedal, your vehicle could move
very rapidly. You could lose control and
hit people or objects. Do not shift into a
drive gear while your engine is running at
high speed.
Notice:Shifting out of PARK (P) or
NEUTRAL (N) with the engine running at high
speed may damage the transmission. The
repairs would not be covered by your warranty.
Be sure the engine is not running at high
speed when shifting your vehicle.
107

DRIVE (D):This position is for normal driving.
It provides the best fuel economy for your vehicle.
If you need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push
your accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push
the accelerator all the way down.
Downshifting the transmission in slippery road
conditions could result in skidding, see “Skidding”
underLoss of Control on page 249.
DRIVE (D) can be used when towing a trailer.
You may want to shift the transmission to
THIRD (3) or, if necessary, a lower gear if the
transmission shifts too often under heavy loads
and/or hilly conditions.
THIRD (3):This position is also used for normal
driving. However it reduces vehicle speed
more than DRIVE (D) without using your brakes.
You might choose THIRD (3) instead of DRIVE (D)
when driving on hilly, winding roads, when
towing a trailer, so there is less shifting between
gears and when going down a steep hill.SECOND (2): This position reduces vehicle speed
even more than THIRD (3) without using your
brakes. You can use SECOND (2) on hills. It can
help control your speed as you go down steep
mountain roads, but then you would also want to
use your brakes off and on.
FIRST (1): This position reduces vehicle speed
even more than SECOND (2) without using
your brakes. You can use it on very steep hills, or
in deep snow or mud. If the shift lever is put in
FIRST (1) while the vehicle is moving forward, the
transmission will not shift into rst gear until the
vehicle is going slowly enough.
Notice:Spinning the tires or holding the
vehicle in one place on a hill using only
the accelerator pedal may damage the
transmission. The repair will not be covered
by your warranty. If you are stuck, do not spin
the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
108

Manual Transmission Operation
This is your shift
pattern.
Here is how to operate your manual transmission:
FIRST (1):Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal
as you slowly press down on the accelerator pedal.
You can shift into FIRST (1) when you are going
less than 20 mph (30 km/h). If you have come to a
complete stop and it is hard to shift into FIRST (1),
put the shift lever in NEUTRAL and let up on the
clutch. Then press the clutch pedal back down and
shift into FIRST (1).SECOND (2):Press the clutch pedal as you
let up on the accelerator pedal and shift into
SECOND (2). Then, slowly let up on the clutch
pedal as you press the accelerator pedal.
THIRD, FOURTH AND FIFTH (3, 4 and 5):
Shift into THIRD (3), FOURTH (4) and FIFTH (5)
the same way you do for SECOND (2). Slowly
let up on the clutch pedal as you press the
accelerator pedal.
To stop, let up on the accelerator pedal and press
the brake pedal. Just before the vehicle stops,
press the clutch pedal and the brake pedal,
and shift to NEUTRAL.
NEUTRAL:Use this position when you start or
idle your engine.
109

REVERSE (R):To back up, press the clutch pedal.
After the vehicle stops, shift into REVERSE (R).
Slowly let up on the clutch pedal as you press the
accelerator pedal. If it is hard to shift, let the shift
lever return to NEUTRAL and release the clutch
pedal. Then press the clutch again and shift into
REVERSE (R). Do not attempt to shift into the fth
gear position prior to shifting into REVERSE (R).
Your transmission has a lock out feature which
prevents a fth gear to reverse gear shift.
Notice:Shifting to REVERSE (R) while your
vehicle is moving forward could damage the
transmission. The repairs would not be covered
by your warranty. Shift to REVERSE (R) only
after your vehicle is stopped.
Use REVERSE (R), along with the parking brake,
for parking your vehicle.
Up-Shift Light
This light will show you
when to shift to the next
higher gear for best
fuel economy.When this light comes on, you can shift to the next
higher gear if weather, road and traffic conditions
permit. For the best fuel economy, accelerate
slowly and shift when the light comes on.
While you accelerate, it is normal for the light to
go on and off if you quickly change the position of
the accelerator. Ignore the shift light when you
downshift.
If your vehicle has four-wheel drive and has a
manual transmission, disregard the shift light when
the transfer case is in four-wheel low.
For more information, seeUp-Shift Light
(Manual Transmission) on page 181.
Shift Speeds
{CAUTION:
If you skip a gear when you downshift,
you could lose control of your vehicle.
You could injure yourself or others.
Do not shift down more than one gear
at a time when you downshift.
110

Full-Time Four-Wheel Drive
Full-Time Four-Wheel Drive sends your engine’s
driving power to all four wheels for extra traction.
To get the most out of Full-Time Four-Wheel
Drive, you must be familiar with its operation.
Transfer Case Buttons
The transfer case buttons are located to the
right of the instrument panel cluster. Use these
switches to shift into and out of the different
Full-Time Four-Wheel Drive modes.You can choose between four modes:
4
m(Four-Wheel High):This setting is used for
driving in most street and highway situations.
You can also use this setting for light or variable
off-road conditions.
N (NEUTRAL):Shift the vehicle’s transfer case
to NEUTRAL only when towing your vehicle.
SeeRecreational Vehicle Towing on page 295
orTowing Your Vehicle on page 294for more
information.
Notice:Driving on pavement in Four-Wheel
High Lock or Four Wheel Low Lock for
extended periods may cause premature wear
on your vehicle’s powertrain and tires. Do not
drive in Four-Wheel High Lock or Four-Wheel
Low Lock on pavement for extended periods.
4
mQ(Four-Wheel-High Lock):Use this
mode when you need extra traction in most
off-road situations such as sand, mud, snow or
level, rocky trails.
111

Notice:Operating your vehicle in
Four-Wheel-Low Lock above 30 mph (48 km/h)
for any extended period of time could cause
damage to the transfer case. Do not operate
your vehicle in Four-Wheel-Low Lock above
30 mph (48 km/h) for extended periods.
4
nQ(Four-Wheel-Low Lock):This mode
delivers extra torque to all four wheels and is used
for extreme off-road conditions. You might
choose 4-Wheel-Low Lock if you are driving in
off-road situations, such as, deep sand, mud, or
snow and climbing or descending steep hills.
If the vehicle has a locking rear axle, when in this
mode you can also choose to lock the rear
axle for additional traction in extreme off-road
situations. SeeLocking Rear Axle on page 243.
Indicator lights in the buttons show which
mode you are in. The indicator lights will come on
briey when you turn on the ignition the mode
the vehicle is in will stay on. If the lights do
not come on, you should take your vehicle to
your dealer for service. An indicator light
will ash while shifting the transfer case.It will remain lit when the shift is complete.
If for some reason the transfer case cannot
make a requested shift, it will return to the
last chosen setting.
If the SERV 4WD message on the Driver
Information Center (DIC) stays on, you should
take your vehicle to your dealer for service. See
Service 4WD message underDIC Warnings
and Messages on page 196.
Shifting between Four-Wheel High and
Four-Wheel-High Lock
With the vehicle traveling less than 45 mph
(72 km/h), press and release the Four-Wheel High
or Four-Wheel-High Lock button. The indicator
light will ash while shifting. It will remain lit when
the shift is complete.
It may be necessary to drive backwards while
turning for a distance of 25 feet (7.5 m) to get the
lock feature to disengage.
112