2010 HUMMER H3 automatic transmission

9-38 Driving and Operating
Leaving Your Vehicle With the
Engine Running (Automatic
Transmission)
{WARNING
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set. And, if you leave the
vehicle with the engine running, it
could overheat and even catch
fire. You or others could be
injured. Do not leave the vehicle
with the engine running.If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you have moved
the shift lever into P (Park), hold
the regular brake pedal down.
Then, see if you can move the shift
lever away from P (Park) without
first pressing the shift lever button.
If you can, it means that the shift
lever was not fully locked into
P (Park).
Torque lock is when the weight
of the vehicle puts too much
force on the parking pawl in the
transmission. This happens when
parking on a hill and shifting the
transmission into P (Park) is not
done properly and then it is difficult
to shift out of P (Park). To prevent
torque lock, set the parking brake
and then shift into P (Park). To find
out how, see
“Shifting Into P (Park)”
listed previously. If torque lock does occur, your
vehicle may need to be pushed
uphill by another vehicle to relieve
the parking pawl pressure, so you
can shift out of P (Park).Shifting Out of Park
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is
designed to:
.Prevent ignition key removal
unless the shift lever is in
P (Park) with the shift lever
button fully released, and
.Prevent movement of the shift
lever out of P (Park) unless
the ignition is in ON/RUN or
ACC/ACCESSORY and the
regular brake pedal is applied.

Driving and Operating 9-41
Running the Vehicle
While Parked
It is better not to park with the
engine running. But if you ever have
to, here are some things to know.
{WARNING
Idling a vehicle in an enclosed
area with poor ventilation is
dangerous. Engine exhaust may
enter the vehicle. Engine exhaust
contains Carbon Monoxide (CO)
which cannot be seen or smelled.
It can cause unconsciousness
and even death. Never run the
engine in an enclosed area that
has no fresh air ventilation. For
more information, seeEngine
Exhaust on page 9‑40.
{WARNING
It can be dangerous to get out
of the vehicle if the automatic
transmission shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the 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 the
vehicle will not move, even when
it is on fairly level ground, always
set the parking brake and move
the automatic transmission shift
lever to P (Park), or the manual
transmission shift lever to Neutral.
Follow the proper steps to be sure
the vehicle will not move. See
Shifting Into Park
on page 9‑37and Parking on page 9‑39.
If pulling a trailer, see Driving
Characteristics and Towing Tips
on
page 9‑70.
Automatic
Transmission
The automatic transmission has a
shift lever on the console.

9-42 Driving and Operating
It features an electronic shift
position indicator within the
instrument cluster.
There are several different positions
for the shift lever.
P (Park):This position locks the
rear wheels. It is the best position
to use when you start the engine
because the vehicle cannot move
easily.
{WARNING
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the 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 the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park
on
page 9‑37
. If you are pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑70. Make sure the shift lever is fully in
P (Park) before starting the engine.
The vehicle has an automatic
transmission shift lock control
system. You must fully apply the
regular brakes first and then press
the shift lever button before you can
shift from P (Park) when the ignition
key is in ON/RUN. If you cannot
shift out of P (Park), ease pressure
on the shift lever and push the shift
lever all the way into P (Park) as
you maintain brake application.
Then press the shift lever button
and move the shift lever into
another gear. See
Shifting Out of
Park on page 9‑38.
R (Reverse): Use this gear to
back up.
Notice: Shifting to R (Reverse)
while the vehicle is moving
forward could damage the
transmission. The repairs would
not be covered by the vehicle
warranty. Shift to R (Reverse) only
after the vehicle is stopped.

9-48 Driving and Operating
If the Four-Wheel-Low Lock button
is pressed when the vehicle is in
gear and/or moving too fast, the
Four-Wheel-Low Lock indicator light
will flash for 15 seconds and not
complete the shift.
Shifting Out of
Four-Wheel-Low Lock
Notice:Shifting the transmission
into gear before the indicator
light stops flashing could cause
damage to the transfer case.
Always wait until the indicator
light stops flashing before putting
the transmission back in gear.
To shift out of Four-Wheel-Low
Lock, the vehicle must be stopped
or moving less than 5 km/h (3 mph)
with the transmission in N (Neutral)
and the ignition in ON/RUN. The
preferred method for shifting out of
Four-Wheel-Low Lock is to have
the vehicle moving 1.6 to 3.2 km/h
(1 to 2 mph). Press and release
the Four-Wheel High or
Four-Wheel-High Lock button. If the vehicle has a manual
transmission, the clutch pedal
must be pressed to the floor while
you press the Four-Wheel High
or Four-Wheel-High Lock button,
or the shift will not be completed.
You must wait for the Four-Wheel
High or Four-Wheel-High Lock
indicator light to stop flashing
and remain lit before shifting the
transmission into gear.
It is normal for the vehicle to have
engagement noise and bump when
shifting between Four-Wheel Low
and Four-Wheel High ranges or
from Neutral.
If the Four-Wheel High or
Four-Wheel-High Lock button is
pressed when the vehicle is in
gear and/or moving too fast,
the Four-Wheel High or
Four-Wheel-High Lock indicator
light will flash for 15 seconds
but will not complete the shift.
Shifting Into Neutral
To shift the transfer case to Neutral:
1. Set the parking brake.
2. Start the vehicle.
3. Put the transmission in
N (Neutral). If the vehicle has a
manual transmission, press and
hold the clutch pedal down while
you perform Steps 5 through 9.
4. Shift the transfer case to Four-Wheel High.
{WARNING
Shifting an all-wheel-drive
vehicle's transfer case into
Neutral can cause the vehicle
to roll even if the automatic
transmission is in P (Park) or the
manual transmission is in any
gear. You or others could be
injured. Make sure the parking
brake is firmly set before you shift
the transfer case to Neutral.

Driving and Operating 9-49
5. Simultaneously press andhold the Four-Wheel High and
Four-Wheel-Low Lock buttons
for 10 seconds. The Neutral light
will come on when the transfer
case shift to Neutral is complete.
6. Press and hold the regular brake pedal and shift the transmission
to R (Reverse), then shift the
transmission to D (Drive) for
an automatic transmission,
or 1 (First) for vehicles have a
manual transmission and then
let out the clutch. This is to
ensure the transfer case is in
Neutral. If not, repeat this
procedure starting at Step 3.
7. Turn the engine off. 8. Place the transmission shift
lever in P (Park) for an automatic
transmission, or 1 (First) for
vehicles that have a manual
transmission.
9. Turn the ignition to LOCK/OFF.
Shifting Out of Neutral
To shift out of Neutral:
1. Set the parking brake and apply the regular brake pedal.
2. Shift the transmission to N (Neutral) for an automatic
transmission, or press the clutch
pedal for vehicles that have a
manual transmission. Then turn
the ignition to ON/RUN but do
not start the engine. 3. Press the button for the
desired transfer case shift
position (Four-Wheel High,
Four-Wheel-High Lock or
Four-Wheel-Low Lock).
After the transfer case has
shifted out of Neutral the light
will go out.
4. Release the parking brake.
Notice: Shifting the transmission
into gear before the indicator
light stops flashing could cause
damage to the transfer case.
Always wait until the indicator
light stops flashing before putting
the transmission back in gear.
5. You may start the engine and shift the transmission to the
desired position.

9-52 Driving and Operating
The stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsations or
pedal movement during this time
is normal and the driver should
continue to apply the brake pedal
as the driving situation dictates.
The brake assist feature will
automatically disengage when
the brake pedal is released or
brake pedal pressure is quickly
decreased.
Hill Start Assist (HSA)
This vehicle has a Hill Start Assist
(HSA) feature, which may be useful
when the vehicle is stopped on a
grade. This feature is designed to
prevent the vehicle from rolling,
either forward or rearward, during
vehicle drive off. After the vehicle
is stopped on an incline, quickly
push the brake pedal to the floor
to activate Hill Start Assist.When the system activates, a
chime will sound and the HSA ON
message will be displayed. The
brakes will automatically be held
for a maximum of two seconds
while the driver switches from
applying the brakes to pushing
the accelerator pedal. When Hill
Start Assist is active, the driver
might experience a
“hard brake
pedal.” This is normal and does
not affect safe brake operation.
After activation, the system will
automatically disengage when the
accelerator pedal is pressed. Do
not turn off the ignition while this
feature is active. The Hill Start
Assist feature may not disengage
fully if the ignition is turned off.
The system will not activate with
the transmission in P (Park), when
traveling down a steep grade in a
drive gear, or if the vehicle is facing
uphill with the transmission in
R (Reverse).
Ride Control Systems
Traction Control
System (TCS)
The vehicle has a Traction Control
System (TCS) that limits wheel
spin. This is especially useful in
slippery road conditions. The
system operates only if it senses
that any of the wheels are spinning
or beginning to lose traction. When
this happens, TCS reduces engine
power. The system may be heard
or felt while it is working. This is
normal and does not mean there is
a problem with the vehicle.
TCS can operate on dry roads
under some conditions. When
this happens, the system may be
heard working or a reduction in
acceleration may be noticed. This
is normal and does not mean there
is a problem with the vehicle.

Driving and Operating 9-53
Examples of these conditions
include hard acceleration in a turn,
an abrupt upshift or downshift of the
transmission or driving on rough
roads.
If cruise control is being used when
TCS begins to limit wheel spin,
the cruise control automatically
disengages. The cruise control
can be re-engaged when road
conditions allow. SeeCruise Control
on page 9‑57for more information.
TRACTION FAILED appears on the
Driver information Center (DIC)
when a TCS or antilock brake
system problem has been detected
and the vehicle needs service.
When this message is on, the
system will not limit wheel spin.
Adjust your driving accordingly.
See Driver Information Center (DIC)
on page 5‑18for more information.
It is recommended to leave the
system on for normal driving
conditions, but it may be necessary
to turn the system off if the vehicle
is stuck in sand, mud, ice, or snow, and it is necessary to
“rock”the
vehicle to attempt to free it. See If
the Vehicle is Stuck
on page 9‑26for more information.
To turn the system off, press and
release the TCS/StabiliTrak button.
When TCS has been turned off, this
light comes on steady and TRAC
OFF appears on the DIC. This light
flashes when TCS is active.
Press and release the
TCS/StabiliTrak button again to
turn the system back on. The TRAC
OFF message then goes off. TCS automatically comes on
whenever the vehicle is started and
resets itself at each ignition cycle.
Adding non‐dealer/non‐retailer
accessories can affect the vehicle's
performance. See
Accessories and
Modifications on page 10‑3.
StabiliTrak System
The vehicle has a vehicle stability
enhancement system called
StabiliTrak. It is an advanced
computer controlled system that
assists the driver with directional
control of the vehicle in difficult
driving conditions.
StabiliTrak activates when the
computer senses a difference
between the intended path and the
direction the vehicle is actually
traveling. StabiliTrak selectively
applies braking pressure at any
one of the vehicle's brakes to assist
the driver with keeping the vehicle
on the intended path.

Driving and Operating 9-71
With the added weight, the engine,
transmission, wheel assemblies and
tires are forced to work harder and
under greater loads. The trailer also
adds wind resistance, increasing
the pulling requirements. For safe
trailering, correctly use the proper
trailering equipment.
The following information has
important trailering tips and rules
for your safety and that of your
passengers. Read this section
carefully before pulling a trailer.
Pulling A Trailer
Here are some important points:
.There are many laws, including
speed limit restrictions that apply
to trailering. Check for legal
requirements with state or
provincial police.
.Consider using a sway control.
See“Hitches” later in this
section.
.Do not tow a trailer at all during
the first 800 km (500 miles) the
new vehicle is driven. The
engine, axle or other parts could
be damaged.
.Then, during the first 800 km
(500 miles) that a trailer is
towed, do not drive over 80 km/h
(50 mph) and do not make starts
at full throttle. This helps the
engine and other parts of the
vehicle wear in at the heavier
loads.
.Vehicles with an automatic
transmission can tow in
D (Drive). Use a lower gear if
the transmission shifts too often.
For vehicles with a manual
transmission, it is better not to
use the highest gear.
.This vehicle has a Hill Start
Assist feature, which may be
useful when the vehicle is
stopped on a grade. See Hill
Start Assist (HSA)
on page 9‑52for more information.
.Do not drive faster than the
maximum posted speed for
trailers.
Driving with a Trailer
Towing a trailer requires experience.
Get familiar with handling and
braking with the added trailer
weight. The vehicle is now longer
and not as responsive as the
vehicle is by itself.
Check all trailer hitch parts and
attachments, safety chains,
electrical connectors, lamps, tires
and mirror adjustments. If the trailer
has electric brakes, start the vehicle
and trailer moving and then apply
the trailer brake controller by hand
to be sure the brakes are working.
During the trip, check occasionally
to be sure that the load is secure,
and the lamps and trailer brakes are
working properly.