2009 GMC SIERRA engine

Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on at or rolling terrain. Tips for driving
in these conditions include:
Keep the vehicle serviced and in good shape.
Check all uid levels and brakes, tires, cooling
system, and transmission.
Going down steep or long hills, shift to a lower gear.
{CAUTION:
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.
{CAUTION:
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.
SeeOff-Road Driving on page 4-12for information
about driving off-road.
4-27

{CAUTION:
Snow can trap engine exhaust under the vehicle.
This may cause exhaust gases to get inside.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in the snow:
Clear away snow from around the base of
your vehicle, especially any that is blocking
the exhaust pipe.
Check again from time to time to be sure
snow does not collect there.
Open a window about two inches (5 cm) on
the side of the vehicle that is away from the
wind to bring in fresh air.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that circulates the air inside the vehicle and
set the fan speed to the highest setting.
See Climate Control System in the Index.
CAUTION: (Continued)
CAUTION: (Continued)
For more information about carbon monoxide, see
Engine Exhaust on page 2-55.
Snow can trap exhaust gases under your vehicle.
This can cause deadly CO (carbon monoxide) gas
to get inside. CO could overcome you and kill you.
You cannot see it or smell it, so you might not
know it is in your vehicle. Clear away snow from
around the base of your vehicle, especially any
that is blocking the exhaust.
Run the engine for short periods only as needed to
keep warm, but be careful.
To save fuel, run the engine for only short periods as
needed to warm the vehicle and then shut the engine
off and close the window most of the way to save heat.
Repeat this until help arrives but only when you feel really
uncomfortable from the cold. Moving about to keep warm
also helps.
If it takes some time for help to arrive, now and then
when you run the engine, push the accelerator pedal
slightly so the engine runs faster than the idle speed.
This keeps the battery charged to restart the vehicle and
to signal for help with the headlamps. Do this as little as
possible to save fuel.
4-29

If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
Slowly and cautiously spin the wheels to free the
vehicle when stuck in sand, mud, ice, or snow.
SeeRocking Your Vehicle to Get It Out on page 4-30.
If the vehicle has a traction system, it can often help
to free a stuck vehicle. Refer to the vehicle’s traction
system in the Index. If stuck too severely for the traction
system to free the vehicle, turn the traction system off
and use the rocking method.
{CAUTION:
If you let your 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 re or other damage.
Spin the wheels as little as possible and avoid
going above 35 mph (55 km/h) as shown on the
speedometer.
For information about using tire chains on the vehicle,
seeTire Chains on page 5-90.
Rocking Your Vehicle to Get It Out
Turn the steering wheel left and right to clear the area
around the front wheels. For four-wheel-drive vehicles,
shift into Four-Wheel High. For vehicles with StabiliTrak
®,
turn the traction control part of the system off. Shift back
and forth between R (Reverse) and a forward gear,
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.
Recovery hooks can be used, if the vehicle has them.
If the vehicle does need to be towed out, seeTowing
Your Vehicle on page 4-45.
4-30

Dinghy Towing
Two-Wheel-Drive Vehicles
Notice:If the vehicle is towed with all four wheels
on the ground, the drivetrain components could
be damaged. The repairs would not be covered by
the vehicle warranty. Do not tow the vehicle with
all four wheels on the ground.
Two-wheel-drive vehicles should not be towed
with all four wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
Four-Wheel-Drive Vehicles
Use the following procedure to dinghy tow a
four-wheel-drive vehicle:
1. Position the vehicle being towed behind the tow
vehicle and shift the transmission to P (Park).
2. Turn the engine off and rmly set the parking brake.
3. Securely attach the vehicle being towed to the
tow vehicle.
4-46

Towing a Trailer
If the vehicle has a diesel engine, see the DURAMAX®
Diesel manual for more information.
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-22for more information.
{CAUTION:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is too
heavy, the brakes may not work well or even at all.
The driver and passengers could be seriously
injured. The vehicle may also be damaged; the
resulting repairs would not be covered by the
vehicle warranty. Pull a trailer only if all the steps in
this section have been followed. Ask your dealer/
retailer for advice and information about towing a
trailer with the vehicle.Notice:Pulling a trailer improperly can damage
the vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your
dealer/retailer for important information about
towing a trailer with the vehicle.
To identify the trailering capacity of the vehicle, read
the information in “Weight of the Trailer” that appears
later in this section.
Trailering is different than just driving the vehicle by
itself. Trailering means changes in handling, acceleration,
braking, durability and fuel economy. Successful, safe
trailering takes correct equipment, and it has to be used
properly.
The following information has many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully
before pulling a trailer.
4-51

Pulling A Trailer
Here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
the rig will be legal, not only where you live but
also where you will be driving. A good source for
this information can be state or provincial police.
Consider using a sway control. See “Hitches” later
in this section.
Do not tow a trailer at all during the rst 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
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 can tow in D (Drive). Shift the transmission
to a lower gear if the transmission shifts too often
under heavy loads and/or hilly conditions.Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
And the weight on the vehicle’s tires
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how much
the vehicle is used to pull a trailer are all important. It can
depend on any special equipment on the 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 the
vehicle can weigh, based upon the vehicle model
and options.
Weights listed apply for conventional trailers and
fth-wheel trailers unless otherwise noted.
4-52

Tow/Haul Mode
Pressing this button at
the end of the shift lever
turns on and off the
tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-34for more information.Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” later in the section. Tow/Haul
is most useful under the following driving conditions:
When pulling a heavy trailer or a large or heavy load
through rolling terrain.
When pulling a heavy trailer or a large or heavy load
in stop and go traffic.
When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benet to the selection of Tow/Haul when
the vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a
heavy trailer or a large or heavy load.
4-69

Driving with a Trailer
{CAUTION:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
Have the exhaust system inspected for
leaks and make necessary repairs before
starting a trip.
Never drive with the liftgate, trunk/hatch,
or rear-most window open.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 2-55.Towing a trailer requires a certain amount of
experience. Get to know the rig before setting out for the
open road. Get acquainted 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
longer and not as responsive as the vehicle is by itself.
Before starting, 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. This checks the electrical connection
at the same time.
During the trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
While towing a trailer or when exposed to long periods
of sunshine, the oor of the truck bed may become
very warm. Avoid putting items in the truck bed
that might be affected by high ambient temperatures.
4-77