engine GMC SIERRA 2010 Owner's Manual

Towing a Trailer
If the vehicle has a diesel engine, see the DURAMAX®
Diesel manual for more information.
If the vehicle has a two–mode hybrid engine, see the
Two–mode Hybrid manual for more information.
Do not tow a trailer during break‐in. SeeNew Vehicle
Break-In
on page 3‑21for more information.
{WARNING:
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.
5-50

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 first 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
.During the first 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. Important considerations that have to do with weight:
.The weight of the trailer
.The weight of the trailer tongue
.The weight on the vehicle's tires
.And the weight of the trailering combination
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. 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.
Trailer weight rating (TWR) is calculated assuming the
tow vehicle has only the driver but all required trailering
equipment. Weight of additional optional equipment,
passengers and cargo in the tow vehicle must be
subtracted from the trailer weight rating.
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
fifth-wheel trailers unless otherwise noted.
5-51

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.
Trailer Brakes
A loaded trailer that weighs more than 2,000 lbs
(900 kg) needs to have its own brake system that is
adequate for the weight of the trailer. Be sure to read
and follow the instructions for the trailer brakes so they
are installed, adjusted and maintained properly.
If the vehicle is equipped with StabiliTrak
®, the trailer
cannot tap into the vehicle's hydraulic brake system.
The trailer brake system can tap into the vehicle's
hydraulic brake system only if:
.The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
.The trailer's brake system will use less than
0.02 cubic inch (0.3 cc) of fluid from the vehicle's
master cylinder. Otherwise, both braking systems
will not work well or at all.
If everything checks out this far, make the brake tap at
the port on the master cylinder that sends the fluid to
the rear brakes. Use only steel brake tubing to make
the tap.
Integrated Trailer Brake Control System
The vehicle may have an
Integrated Trailer Brake
Control (ITBC) system for
electric trailer brakes.
This symbol is located on the Trailer Brake Control
Panel on vehicles with an Integrated Trailer Brake
Control System. The power output to the trailer brakes
is based on the amount of brake pressure being applied
by the vehicle’ s brake system. This available power
output to the trailer brakes can be adjusted to a wide
range of trailering situations.
The ITBC system is integrated with the vehicle’s brake,
anti‐lock brake and StabiliTrak (if equipped) systems.
In trailering conditions that cause the vehicle’s anti‐lock
brake or StabiliTrak systems to activate, power sent to
the trailer's brakes will be automatically adjusted to
minimize trailer wheel lock-up. This does not imply that
the trailer has the StabiliTrak system.
5-64

To determine if the electrical fault is on the vehicle side
or trailer side of the trailer wiring harness connection,
do the following:1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message re-appears, the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING message only
re-appears when connecting the trailer wiring
harness to the vehicle, the electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE SYSTEM –This message
will be displayed when there is a problem with the ITBC
system. If this message persists over multiple ignition
cycles there is a problem with the ITBC system. Take
the vehicle to an authorized GM dealer to have the
ITBC system diagnosed and repaired.
If either the CHECK TRAILER WIRING or SERVICE
TRAILER BRAKE SYSTEM message is displayed while
driving the vehicle, power is no longer available to the
trailer brakes. When traffic conditions allow, carefully pull the vehicle over to the side of the road and turn the
ignition off. Check the wiring connection to the trailer
and turn the ignition back on. If either of these
messages continues, either the vehicle or trailer
needs service.
An authorized GM dealer may be able to diagnose and
repair problems with the trailer. However, any diagnosis
and repair of the trailer is not covered under the vehicle
warranty. Please contact your trailer dealer for
assistance with trailer repairs and trailer warranty
information.
Driving with a Trailer
{WARNING:
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.
(Continued)
5-70

WARNING: (Continued)
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 3‑54.
Towing a trailer requires a certain amount of
experience. The combination you are driving is longer
and not as responsive as the vehicle itself. Get
acquainted with the handling and braking of the rig
before setting out for the open road. Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors,
lamps, tires and mirrors. If the trailer has electric
brakes, start the combination moving and then apply the
trailer brake controller by hand to be sure the
brakes work.
During the trip, check occasionally to be sure that the
load is secure and the lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving the vehicle without a trailer.
This can help to avoid heavy braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.
The combination will not accelerate as quickly and is
longer so it is necessary to go much farther beyond the
passed vehicle before returning to the lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
To move the trailer to the left, 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.
5-71

Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. The vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft
shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn out, the arrows on the
instrument panel will still flash for turns. It is important to
check occasionally to be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower gear beforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might get hot and no
longer work well.
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.
The tow/haul mode may be used if the transmission
shifts too often. See Tow/Haul Mode on page 3‑34. When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If the engine
is turned off immediately after towing at high altitude on
steep uphill grades, the vehicle may show signs similar
to engine overheating. To avoid this, let the engine run
while parked, preferably on level ground, with the
automatic transmission in P (Park) for a few minutes
before turning the engine off. If the overheat warning
comes on, see
Engine Overheating on page 6‑34.
Parking on Hills
{WARNING:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on
a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
5-72

2. Have someone place chocks under the trailerwheels.
3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
5. If the vehicle is four-wheel-drive, be sure the transfer case is in a drive gear and not in
N (Neutral).
6. Release the brake pedal.
{WARNING:
It can be 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.
If the engine has been left running, the vehicle
can move suddenly. You or others could be
injured. To be sure the vehicle will not move, even
when on fairly level ground, use the steps that
follow. (Continued)
WARNING: (Continued)
Always put the shift lever fully in P (Park) with the
parking brake firmly set.
If the transfer case on a four-wheel-drive vehicle
is in N (Neutral), the vehicle will be free to roll,
even if the shift lever is in P (Park). Be sure the
transfer case is in a drive gear—not in
N (Neutral).
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine
3. Shift into a gear
4. Release the parking brake
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
5-73

Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual's Maintenance Schedule or
Index for more information. Things that are especially
important in trailer operation are automatic transmission
fluid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect these
before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle is equipped with one of the following wiring
harnesses for towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew cab pickups have a
seven‐wire trailer towing harness.
For vehicles not equipped with heavy duty trailering, the
harness is secured to the vehicle's frame behind the
spare tire mount. The harness requires the installation
of a trailer connector, which is available through your
dealer/retailer.
If towing a light‐duty trailer with a standard four‐way
round pin connector, an adapter is available from your
dealer/retailer.
Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy duty trailering, the
harness is connected to a bracket on the hitch platform.
The seven-wire harness contains the following trailer
circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
5-74

Section 6 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Accessories and Modifications . . . . . . . . . . . . . . . . . . 6-4
California Proposition 65 Warning . . . . . . . . . . . . . . . 6-5
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 6-5
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . 6-11
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 6-13 Checking Things Under the Hood
. . . . . . . . . . . . . . .6-14
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
Engine Compartment Overview . . . . . . . . . . . . . . . . 6-16
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 6-21
Automatic Transmission Fluid (4-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-23
Automatic Transmission Fluid (6-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . 6-26
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31
Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 6-37
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 6-38
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-43
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44
6-1

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of California
to cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems, many
fluids, and some component wear by-products contain
and/or emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as airbag
initiators, seat belt pretensioners, and lithium batteries
contained in remote keyless transmitters, may contain
perchlorate materials. Special handling may be
necessary. For additional information, see
www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
If this vehicle is a Two‐mode Hybrid, see the Two‐mode
Hybrid manual for more information.
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
.Be sure you have sufficient knowledge,
experience, the proper replacement parts, and
tools before attempting any vehicle
maintenance task.
.Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off. You
could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order the
proper service manual, see Service Publications
Ordering Information on page 8‑16.
This vehicle has an airbag system. Before attempting
to do your own service work, see Servicing Your
Airbag-Equipped Vehicle on page 2‑91.
6-5