GMC SIERRA 1500 2012 Owners Manual

Black plate (75,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-75
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.
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.(Continued)
WARNING (Continued)
.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 9‑33.
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.

Black plate (76,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-76 Driving and Operating
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.
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 9‑39.
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 10‑22.
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.

Black plate (77,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-77
If parking the rig on a hill:
1. Press the brake pedal, but donot shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
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.
Always put the shift lever fully in
P (Park) with the parking brake
firmly set. (Continued)
WARNING (Continued)
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.

Black plate (78,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-78 Driving and Operating
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11‑3. 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 Towing
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Do not tow a trailer during break-in.
SeeNew Vehicle Break-In on
page 9‑25 for 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 for advice and information
about towing a trailer with the
vehicle.

Black plate (79,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-79
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 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” 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.
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.
For kingpin weight and trailer
tongue weight information, see
“Weight of the Trailer Tongue”
later
in this section.

Black plate (80,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-80 Driving and Operating
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.Vehicle Axle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 2WD Regular Cab Standard Box
4.3L V6 (b) 3.232 177 kg (4,800 lbs) 4 309 kg (9,500 lbs)
4.3L V6 —With Automatic
Transmission (b) 3.73
2 449 kg (5,400 lbs) 4 536 kg (10,000 lbs)
4.3L V6 —With Manual
Transmission (b) 3.73
1 860 kg (4,100 lbs) 3 938 kg (8,683 lbs)
4.8L V8 (b) 3.232 132 kg (4,700 lbs) 4 309 kg (9,500 lbs)
4.8L V8 (b) 3.733 266 kg (7,200 lbs) 5 443 kg (12,000 lbs)
5.3L LMG V8 (b) 3.082 994 kg (6,600 lbs) 5 216 kg (11,500 lbs)
5.3L LMG V8, K5L HD
Cooling Pkg 3.08
3 357 kg (7,400 lbs) 5 534 kg (12,200 lbs)
5.3L LMG V8 K5L HD Cooling Pkg 3.42 4 128 kg (9,100 lbs) 6 350 kg (14,000 lbs)
1500 Series 2WD Extended Cab Standard Box 4.3L V6 (b) 3.231 996 kg (4,400 lbs) 4 309 kg (9,500 lbs)
4.8L V8 (b) 3.232 132 kg (4,700 lbs) 4 536 kg (10,000 lbs)
4.8L V8 (b) 3.733 039 kg (6,700 lbs) 5 443 kg (12,000 lbs)

Black plate (81,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-81
VehicleAxle Ratio Maximum Trailer Weight GCWR (a)
5.3L V8 (b) 3.082 812 kg (6,200 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg (b) 3.083 130 kg (6,900 lbs) 5 534 kg (12,200 lbs)
5.3L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 400 kg (9,700 lbs) 6 804 kg (15,000 lbs)
5.3L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 264 kg (9,400 lbs) 6 804 kg (15,000 lbs)
6.2L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 400 kg (9,700 lbs) 6 804 kg (15,000 lbs)
6.2L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 264 kg (9,400 lbs) 6 804 kg (15,000 lbs)
6.2L V8 NHT Max Trailering
Pkg —Conventional Trailer 3.73
4 853 kg (10,700 lbs) 7 257 kg (16,000 lbs)
6.2L V8 NHT Max Trailering
Pkg —Fifth-Wheel Trailer 3.73
4 808 kg (10,600 lbs) 7 257 kg (16,000 lbs)
1500 Series 2WD Crew Cab Short Box (b) 4.8L V8 3.232 132 kg (4,700 lbs) 4 536 kg (10,000 lbs)
4.8L V8 3.733 039 kg (6,700 lbs) 5 443 kg (12,000 lbs)
5.3L V8 (LMG) 3.082 812 kg (6,200 lbs) 5 216 kg (11,500 lbs)

Black plate (82,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-82 Driving and Operating
VehicleAxle Ratio Maximum Trailer Weight GCWR (a)
5.3L V8 (LMG) K5L HD
Cooling Pkg 3.08
3 130 kg (6,900 lbs) 5 534 kg (12,200 lbs)
5.3L V8 (LC9) XFE 3.083 175 kg (7,000 lbs) 5 534 kg (12,200 lbs)
5.3L V8 (LMG) K5L HD
Cooling Pkg 3.42
4 355 kg (9,600 lbs) 6 804 kg (15,000 lbs)
6.2L V8 K5L HD Cooling Pkg 3.424 400 kg (9,700 lbs) 6 804 kg (15,000 lbs)
6.2L V8 NHT Max Trailering Pkg 3.734 808 kg (10,600 lbs) 7 257 kg (16,000 lbs)
1500 Series 2WD Regular Cab Long Box 4.3L V6 (b) 3.232 132 kg (4,700 lbs) 4 309 kg (9,500 lbs)
4.3L V6 (b) 3.732 359 kg (5,200 lbs) 4 536 kg (10,000 lbs)
4.8L V8 (b) 3.232 313 kg (5,100 lbs) 4 536 kg (10,000 lbs)
4.8L V8 (b) 3.733 221 kg (7,100 lbs) 5 443 kg (12,000 lbs)
5.3L V8 3.082 948 kg (6,500 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.083 266 kg (7,200 lbs) 5 534 kg (12,200 lbs)
5.3L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 536 kg (10,000 lbs) 6 804 kg (15,000 lbs)
5.3L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 037 kg (8,900 lbs) 6 804 kg (15,000 lbs)

Black plate (83,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-83
VehicleAxle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 2WD Extended Cab Long Box 5.3L V8 (b) 3.082 722 kg (6,000 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg (b) 3.083 039 kg (6,700 lbs) 5 534 kg (12,200 lbs)
5.3L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 309 kg (9,500 lbs) 6 804 kg (15,000 lbs)
5.3L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 082 kg (9,000 lbs) 6 804 kg (15,000 lbs)
1500 Series 4WD Regular Cab Standard Box 4.3L V6 (b) 3.732 313 kg (5,100 lbs) 4 536 kg (10,000 lbs)
4.8L V8 (b) 3.422 722 kg (6,000 lbs) 4 990 kg (11,000 lbs)
5.3L V8 (b) 3.082 903 kg (6,400 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg 3.083 221 kg (7,100 lbs) 5 534 kg (12,200 lbs)
5.3L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 037 kg (8,900 lbs) 6 350 kg (14,000 lbs)
5.3L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
3 719 kg (8,200 lbs) 6 350 kg (14,000 lbs)

Black plate (84,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-84 Driving and Operating
VehicleAxle Ratio Maximum Trailer Weight GCWR (a)
1500 Series 4WD Extended Cab Standard Box 4.8L V8 (b) 3.422 495 kg (5,500 lbs) 4 990 kg (11,000 lbs)
5.3L V8 (b) 3.082 767 kg (6,100 lbs) 5 216 kg (11,500 lbs)
5.3L V8 K5L HD Cooling Pkg (b) 3.083 084 kg (6,800 lbs) 5 534 kg (12,200 lbs)
5.3L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 354 kg (9,600 lbs) 6 804 kg (15,000 lbs)
5.3L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 354 kg (9,600 lbs) 6 804 kg (15,000 lbs)
6.2L V8 K5L HD Cooling
Pkg —Conventional Trailer 3.42
4 264 kg (9,400 lbs) 6 804 kg (15,000 lbs)
6.2L V8 K5L HD Cooling
Pkg —Fifth-Wheel Trailer 3.42
4 128 kg (9,100 lbs) 6 804 kg (15,000 lbs)
6.2L V8 NHT Max Trailering
Pkg —Conventional Trailer 3.73
4 717 kg (10,400 lbs) 7 257 kg (16,000 lbs)
6.2L V8 NHT Max Trailering
Pkg —Fifth-Wheel Trailer 3.73
4 672 kg (10,300 lbs) 7 257 kg (16,000 lbs)
1500 Series 4WD Crew Cab Short Box (b) 4.8L V8 3.422 495 kg (5,500 lbs) 4 990 kg (11,000 lbs)
5.3L V8 3.082 722 kg (6,000 lbs) 5 216 kg (11,500 lbs)