transmission HUMMER H3 2010 Owner's Manual

9-12 Driving and Operating
For mounds, washouts, loose
up-hill slopes, ditches, etc.
When wheel spin occurs as the
vehicle is moving, the driver
may notice a slight shaking or
shuddering of the vehicle. This
should be stopped as soon as
possible to prevent damage to
vehicle components. This is the
indication that a loss of traction is
occurring on this terrain. The
operator should:
1. Reduce speed and apply thebrakes.
2. Assess the terrain properly and adjust vehicle speed and gear
ranges accordingly: Four‐Wheel
High position for higher speeds
and Four‐Wheel‐Low Lock for
more torque and lower speeds.
Transmission 1 (First) gear is
generally recommended. 3. Apply slight pressure to the
brake when the shaking or
shuddering sensation is felt,
keeping the vehicle moving in
a controlled manner.
4. Be prepared to alternate between braking and
accelerating through the
adverse terrain.
Getting Familiar with Off-Road
Driving
It is a good idea to practice in an
area that is safe and close to home
before you go into the wilderness.
Off-roading requires some new and
different skills.
Tune your senses to different kinds
of signals. Your eyes need to
constantly sweep the terrain for
unexpected obstacles. Your ears
need to listen for unusual tire or
engine sounds. Use your arms,
hands, feet, and body to respond to
vibrations and vehicle bounce. Controlling the vehicle is the key to
successful off-road driving. One of
the best ways to control the vehicle
is to control the speed. At higher
speeds:
.You approach things faster and
have less time to react.
.There is less time to scan the
terrain for obstacles.
.The vehicle has more bounce
when driving over obstacles.
.More braking distance is
needed, especially on an
unpaved surface.
{WARNING
When you are driving off-road,
bouncing and quick changes in
direction can easily throw you
out of position. This could cause
you to lose control and crash.
So, whether you are driving on
or off the road, you and your
passengers should wear safety
belts.

9-14 Driving and Operating
Crossing Obstacles
Approach Angle—a Key to
Mobility
If you encounter a large dip in the
terrain, do not enter straight on;
enter at an angle —15° minimum
approach (A), 75° maximum
approach angle (B). For very large
dips, ditches or small washes, coast
in, using the engine as a brake
(transmission and transfer case
lowest gears). Then, use the low
ranges in the transmission and
transfer case to power out. Roll The Tires Over Large Rocks
Do not straddle large rocks; drive
over them, letting the tire cover the
rock. The tread of the tire is thicker
and tougher than the sidewall of the
tire and is more resilient to impact
than underbody components.
Log Crossing
Using the proper technique,
the vehicle will cross logs up to
25.4 cm (10 inches) in diameter.
Approach the log at approximately a
15° angle (A) with the transmission
in 1 (First) and the transfer case in
Four‐Wheel‐Low Lock and
“walk”the vehicle over, one tire at a time.
It may be necessary to modulate
the brake pedal and accelerator to
avoid spin-out. Ease the vehicle
down from the log with the brake.
Driving on Hills
Off-road driving often takes you up,
down, or across a hill. Driving safely
on hills requires good judgment
and an understanding of what the
vehicle can and cannot do. There
are some hills that simply cannot be
driven, no matter how well built the
vehicle.

Driving and Operating 9-15
{WARNING
Many hills are simply too steep
for any vehicle. If you drive up
them, you will stall. If you drive
down them, you cannot control
your speed. If you drive across
them, you will roll over. You could
be seriously injured or killed.
If you have any doubt about the
steepness, do not drive the hill.
Approaching a Hill
When you approach a hill, decide if
it is too steep to climb, descend,
or cross. Steepness can be hard to
judge. On a very small hill, for
example, there may be a smooth,
constant incline with only a small
change in elevation where you can
easily see all the way to the top.
On a large hill, the incline may get
steeper as you near the top, but you
might not see this because the crest
of the hill is hidden by bushes,
grass, or shrubs.Consider this as you approach a hill:
.Is there a constant incline,
or does the hill get sharply
steeper in places?
.Is there good traction on the
hillside, or will the surface cause
tire slipping?
.Is there a straight path up or
down the hill so you will not
have to make turning
maneuvers?
.Are there obstructions on the hill
that can block your path, such
as boulders, trees, logs, or ruts?
.What is beyond the hill? Is there
a cliff, an embankment, a
drop-off, a fence? Get out and
walk the hill if you do not know.
It is the smart way to find out.
.Is the hill simply too rough?
Steep hills often have ruts,
gullies, troughs, and exposed
rocks because they are more
susceptible to the effects of
erosion.See
Hill Start Assist (HSA)
on
page 9‑52for information on
vehicles stopped on a grade.
Driving Uphill
Once you decide it is safe to drive
up the hill:
.Use transmission and transfer
case low gear and get a firm grip
on the steering wheel.
.Get a smooth start up the hill
and try to maintain speed. Not
using more power than needed
can avoid spinning the wheels or
sliding.
.Let the traction system work to
control any wheel slippage. The
traction control system allows for
moderate wheel spin with some
capability to dig in and power up
the hill.

9-16 Driving and Operating
.Do not continue if the vehicle
shudders or exhibits suspension
hopping. This can cause
damage to the driveline or
suspension components.
Improper driving technique is not
covered by the vehicle warranty.
{WARNING
Turning or driving across steep
hills can be dangerous. You could
lose traction, slide sideways, and
possibly roll over. You could be
seriously injured or killed. When
driving up hills, always try to go
straight up.
.Try to drive straight up the hill if
at all possible. If the path twists
and turns, you might want to find
another route.
.Ease up on the speed as you
approach the top of the hill.
.Attach a flag to the vehicle to be
more visible to approaching
traffic on trails or hills.
.Sound the horn as you approach
the top of the hill to let opposing
traffic know you are there.
.Use headlamps even during the
day to make the vehicle more
visible to oncoming traffic.
{WARNING
Driving to the top (crest) of a
hill at full speed can cause an
accident. There could be a
drop-off, embankment, cliff,
or even another vehicle. You
could be seriously injured or
killed. As you near the top of a
hill, slow down and stay alert.If the vehicle stalls, or is about to
stall, and you cannot make it up
the hill:
.Push the brake pedal to stop
the vehicle and keep it from
rolling backwards and apply the
parking brake.
.If the engine is still running, shift
the transmission to R (Reverse),
release the parking brake, and
slowly back down the hill in
R (Reverse).
.If the engine has stopped
running, you need to restart it.
With the brake pedal pressed,
apply the parking brake. If the
vehicle has an automatic
transmission, shift the
transmission to P (Park).
Restart the engine. Then, shift
to R (Reverse), release the
parking brake, and slowly back
down the hill as straight as
possible in R (Reverse).

Driving and Operating 9-17
.While backing down the hill, put
your left hand on the steering
wheel at the 12 o'clock position
so you can tell if the wheels are
straight and can maneuver as
you back down. It is best to back
down the hill with the wheels
straight rather than in the left or
right direction. Turning the wheel
too far to the left or right will
increase the possibility of a
rollover.
Things not to do if the vehicle stalls,
or is about to stall, when going up
a hill:
.Never attempt to prevent a stall
by shifting into N (Neutral) to
rev-up the engine and regain
forward momentum. This will
not work. The vehicle can roll
backward very quickly and could
go out of control.
.Never try to turn around if about
to stall when going up a hill.
If the hill is steep enough to stall
the vehicle, it is steep enough
to cause it to roll over. If you
cannot make it up the hill, back
straight down the hill.
If, after stalling, you try to back
down the hill and decide you just
cannot do it, set the parking brake.
If the vehicle has an automatic
transmission, shift to P (Park). Turn
off the engine. Leave the vehicle
and go get some help. Exit on the
uphill side and stay clear of the path
the vehicle would take if it rolled
downhill. Do not shift the transfer
case to Neutral when you leave the
vehicle. Leave it in some gear.
{WARNING
Shifting the transfer case to
Neutral can cause your vehicle to
roll even if the transmission is in
P (Park). This is because the
Neutral position on the transfer
case overrides the transmission.
You or someone else could be
injured. If you are going to leave
your vehicle, set the parking
brake and shift the transmission
to P (Park). But do not shift the
transfer case to Neutral.

9-18 Driving and Operating
Driving Downhill
When off-roading takes you
downhill, consider:
.How steep is the downhill?
Will I be able to maintain vehicle
control?
.What is the surface like?
Smooth? Rough? Slippery?
Hard-packed dirt? Gravel?
.Are there hidden surface
obstacles? Ruts? Logs?
Boulders?
.What is at the bottom of the hill?
Is there a hidden creek bank or
even a river bottom with large
rocks?
If you decide you can go down
a hill safely, try to keep the vehicle
headed straight down. Use a low
gear so engine drag can help the
brakes so they do not have to do all
the work. Descend slowly, keeping
the vehicle under control at all
times.
{WARNING
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and a
serious accident. Apply the
brakes lightly when descending a
hill and use a low gear to keep
vehicle speed under control.
Things not to do when driving down
a hill:
.When driving downhill, avoid
turns that take you across the
incline of the hill. A hill that is not
too steep to drive down might be
too steep to drive across. The
vehicle could roll over.
.Never go downhill with the
transmission in N (Neutral),
called free-wheeling. The brakes
will have to do all the work and
could overheat and fade. Vehicles are much more likely to
stall when going uphill, but if it
happens when going downhill:
1. Stop the vehicle by applying the
regular brakes and apply the
parking brake.
2. With an automatic transmission, shift to P (Park). While still
braking, restart the engine.
3. Shift back to a low gear, release the parking brake, and drive
straight down.
4. If the engine will not start, get out and get help.

Driving and Operating 9-23
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving—scan
the road ahead and to the sides.
.Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Going down steep or long hills,
shift to a lower gear.
{WARNING
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
{WARNING
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. The brakes will have
to do all the work of slowing down
and they could get so hot that
they would not work well. You
would then have poor braking or
even none going down a hill. You
could crash. Always have the
engine running and the vehicle in
gear when going downhill.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Top of hills: Be alert —
something could be in your
lane (stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.

9-26 Driving and Operating
If the Vehicle is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
If stuck too severely for the traction
system to free the vehicle, turn the
traction system off and use the
rocking method.
{WARNING
If the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 55 km/h (35 mph) as
shown on the speedometer.
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑64.
Rocking the Vehicle to Get
it Out
Turn the steering wheel left and
right to clear the area around the
front wheels. Turn off any traction
system. Shift back and forth
between R (Reverse) and a forward
gear, or with a manual transmission,
between 1 (First) or 2 (Second) and
R (Reverse), spinning the wheels
as little as possible. To prevent
transmission wear, wait until the
wheels stop spinning before shifting
gears. Release the accelerator
pedal while shifting, and press
lightly on the accelerator pedal
when the transmission is in gear.
Slowly spinning the wheels in the
forward and reverse directions
causes a rocking motion that could
free the vehicle. If that does not get
the vehicle out after a few tries, it
might need to be towed out. The
recovery loops can be used. If the
vehicle does need to be towed out,
see Towing the Vehicle
on
page 10‑90. Recovery Loops
{WARNING
These loops, when used, are
under a lot of force. Keep people
away from the vicinity of the loops
and any chains or cables during
use. Always pull the vehicle
straight out. Never pull on the
loops at a sideways angle. The
loops could break off and you or
others could be injured from the
chain or cable snapping back.
Notice: Never use the recovery
loops to tow the vehicle. The
vehicle could be damaged and
it would not be covered by the
vehicle warranty.

9-34 Driving and Operating
Ignition Positions
The ignition switch has four different
positions.
To shift out of P (Park), turn the
ignition to ON/RUN and apply the
regular brake pedal.
Notice:Using a tool to force the
key to turn in the ignition could
cause damage to the switch or
break the key. Use the correct
key, make sure it is all the way in,
and turn it only with your hand.
If the key cannot be turned by
hand, see your dealer. (A) LOCK/OFF:
This position
locks the ignition. It also locks
the transmission on automatic
transmission vehicles. It locks
the steering wheel on manual
transmission vehicles. The key can
only be removed in LOCK/OFF.
On vehicles with an automatic
transmission, the shift lever must be
in P (Park) to turn the ignition switch
to LOCK/OFF.
The steering can bind with the
wheels turned off center. If this
happens, move the steering wheel
from right to left while turning the
key to ACC/ACCESSORY. If this
doesn't work, then the vehicle needs
service.
(B) ACC/ACCESSORY: This is the
position in which you can operate
the electrical accessories or items
plugged into the accessory power
outlets. On automatic transmission
vehicles, this position unlocks the
ignition. On manual transmission
vehicles, it unlocks the ignition and steering wheel. Use this position
if the vehicle must be pushed or
towed.
(C) ON/RUN:
This position can
be used to operate the electrical
accessories and to display some
instrument panel cluster warning
and indicator lights. The switch
stays in this position when the
engine is running. The transmission
is also unlocked in this position on
automatic transmission vehicles.
If you leave the key in the
ACC/ACCESSORY or ON/RUN
position with the engine off, the
battery could be drained. You may
not be able to start the vehicle if the
battery is allowed to drain for an
extended period of time.
(D) START: This is the position that
starts the engine. When the engine
starts, release the key. The ignition
switch returns to ON/RUN for
driving.

Driving and Operating 9-35
A warning tone will sound when the
driver door is opened, the ignition is
in ACC/ACCESSORY or LOCK/OFF
and the key is in the ignition.
Retained Accessory
Power (RAP)
These vehicle accessories can be
used for up to 20 minutes after the
engine is turned off:
.Audio System
.Front Wipers
.Power Windows
.Sunroof (if equipped)
These features will work when
the key is in ON/RUN or
ACC/ACCESSORY. Once the
key is turned from ON/RUN to
LOCK/OFF, these features continue
working for up to 20 minutes or until
a door is opened.
Starting the Engine
Place the transmission in the
proper gear.
Automatic Transmission
Move the shift lever to P (Park) or
N (Neutral). The engine will not start
in any other position. To restart the
vehicle when it is already moving,
use N (Neutral) only.
Notice: Do not try to shift to
P (Park) if the vehicle is moving.
If you do, you could damage the
transmission. Shift to P (Park)
only when the vehicle is stopped.
Manual Transmission
The shift lever should be in
N (Neutral) and the parking brake
engaged. Hold the clutch pedal
down to the floor and start the
engine. The vehicle will not start
if the clutch pedal is not all the
way down. Starting Procedure
1. With your foot off the accelerator
pedal, turn the ignition key to
START. When the engine starts,
let go of the key. The idle speed
will go down as the engine
warms. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently to allow
the oil to warm up and lubricate
all moving parts.
The vehicle has a
Computer-Controlled Cranking
System. This feature assists in
starting the engine and protects
components. If the ignition key is
turned to the START position,
and then released when the
engine begins cranking, the
engine will continue cranking
for a few seconds or until the
vehicle starts. If the engine
does not start and the key is
held in START for many
seconds, cranking will be
stopped after 15 seconds to
prevent cranking motor damage.