towing GMC SIERRA 1500 2013 Owner's Manual

Black plate (23,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-23
Starting and
Operating
New Vehicle Break-In
Notice:The vehicle does not
need an elaborate break-in. But it
will perform better in the long run
if you follow these guidelines:
.Keep the vehicle speed at
88 km/h (55 mph) or less for
the first 805 km (500 miles).
.Do not drive at any one
constant speed, fast or slow,
for the first 805 km
(500 miles). Do not make
full-throttle starts. Avoid
downshifting to brake or
slow the vehicle.
.Avoid making hard stops for
the first 322 km (200 miles) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
premature wear and earlier
replacement. Follow this breaking-in guideline every
time you get new brake
linings.
.Do not tow a trailer during
break-in. See
Trailer Towing
on page 9‑73 for the trailer
towing capabilities of the
vehicle and more
information.
Following break‐in, engine speed
and load can be gradually
increased.
Adjustable Throttle and
Brake Pedal
On vehicles with this feature, you
can change the position of the
throttle and brake pedals.
No adjustment to the pedals can be
made when the vehicle is in
R (Reverse) or while using cruise
control.
The control used to adjust the
pedals is located on the instrument
panel below the climate control
system.
Press the bottom of the control to
move the pedals closer. Press the
top of the control to move the
pedals away.
Before you start driving, fully press
the brake pedal to confirm the
adjustment is right for you. While
driving, make only small
adjustments.
The vehicle may have a memory
function which lets pedal settings be
saved and recalled. See Memory
Seats on page 3‑6.

Black plate (29,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-29
WARNING (Continued)
case is in a drive gear. If towing a
trailer, seeDriving Characteristics
and Towing Tips on page 9‑71.
1. Hold the brake pedal down, then set the parking brake.
See Parking Brake on page 9‑51
for more information.
2. Move the shift lever into the P (Park) position by pulling the
shift lever toward you and
moving it up as far as it will go.
3. Be sure the transfer case is in a drive gear —not in N (Neutral).
4. Turn the ignition key to LOCK/OFF.
5. Remove the key and take it with you. If you can leave the vehicle
with the ignition key in your
hand, the vehicle is in P (Park).
Leaving the Vehicle With the
Engine Running
{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.
If you have four-wheel drive and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). So be sure the transfer
case is in a drive gear —not in
N (Neutral).
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 unless you have to. If you have to leave the vehicle with
the engine running, be sure your
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you move 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 pulling it toward
you. If you can, it means that the
shift lever was not fully locked into
P (Park).
Torque Lock
If you are parking on a hill and you
do not shift your transmission into
P (Park) properly, the weight of the
vehicle may put too much force on
the parking pawl in the
transmission. You may find it difficult
to pull the shift lever out of P (Park).
This is called torque lock. To
prevent torque lock, set the parking
brake and then shift into P (Park)
properly before you leave the driver
seat. To find out how,
Shifting Into
Park on page 9‑28.

Black plate (32,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-32 Driving and Operating
Running the Vehicle
While Parked
It is better not to park with the
engine running.
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
SeeShifting Into Park on page 9‑28
and Engine Exhaust on page 9‑31.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips on page 9‑71.
Automatic
Transmission
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Vehicles with an automatic
transmission have an electronic shift
position indicator within the
instrument panel cluster. This
display comes on when the ignition
key is turned to the ON/RUN
position.
There are several different positions
for the shift lever.
Hydra-Matic®4-Speed Automatic
Transmission
Heavy Duty 6-Speed Automatic
Transmission Shown (Light Duty 6-Speed Similar)
See “Range Selection Mode” under
Manual Mode on page 9‑36.
P (Park): This position locks the
rear wheels. It is the best position to
use when starting the engine
because the vehicle cannot move
easily. When parked on a hill,

Black plate (33,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-33
especially when the vehicle has a
heavy load, you might notice an
increase in the effort to shift out of
P (Park). See“Torque Lock” under
Shifting Into Park on page 9‑28 for
more information.
{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. 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 9‑28 andDriving
Characteristics and Towing Tips
on page 9‑71.
{WARNING
If you have Four-Wheel Drive, the
vehicle will be free to roll —even
if the shift lever is in P (Park) —if
the transfer case is in Neutral. So,
be sure the transfer case is in a
drive gear, Two-Wheel Drive High
or Four-Wheel Drive High or
Four-Wheel Drive Low —not in
Neutral. See Shifting Into Park on
page 9‑28.
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.
To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, see If
the Vehicle Is Stuck on page 9‑14. N (Neutral):
In this position, the
engine does not connect with the
wheels. To restart when you are
already moving, use N (Neutral)
only. Also, use N (Neutral) when the
vehicle is being towed.
{WARNING
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
Notice: Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.

Black plate (34,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-34 Driving and Operating
D (Drive):This position is for
normal driving. It provides the best
fuel economy. If you need more
power for passing, and you are:
.Going less than about 55 km/h
(35 mph), push the accelerator
pedal about halfway down.
.Going about 55 km/h (35 mph) or
more, push the accelerator all
the way down.
By doing this, the vehicle shifts
down to the next gear and has
more power.
D (Drive) can be used when towing
a trailer, carrying a heavy load,
driving on steep hills, or for off-road
driving. You might want to shift the
transmission to a lower gear
selection if the transmission shifts
too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “Skidding”under
Loss of Control on page 9‑5. The vehicle has a shift stabilization
feature that adjusts the transmission
shifting to the current driving
conditions in order to reduce rapid
upshifts and downshifts. This shift
stabilization feature is designed to
determine, before making an
upshift, if the engine is able to
maintain vehicle speed by analyzing
things such as vehicle speed,
throttle position, and vehicle load.
If the shift stabilization feature
determines that a current vehicle
speed cannot be maintained, the
transmission does not upshift and
instead holds the current gear.
In some cases, this could appear to
be a delayed shift, however the
transmission is operating normally.
The transmission uses adaptive
shift controls. Adaptive shift controls
continually compares key shift
parameters to pre-programmed
ideal shifts stored in the
transmissions computer. The
transmission constantly makes
adjustments to improve vehicle
performance according to how thevehicle is being used, such as with
a heavy load or when temperature
changes. During this adaptive shift
control process, shifting might feel
different as the transmission
determines the best settings.
When temperatures are very cold,
the Allison Transmission and
Hydra-Matic 6-Speed transmission's
gear shifting could be delayed
providing more stable shifts until the
engine warms up. Shifts could be
more noticeable with a cold
transmission. This difference in
shifting is normal.
M (Manual Mode):
This position is
available on vehicles with the
Allison Transmission or Hydra-Matic
6-Speed transmission. It lets drivers
select the range of gears
appropriate for current driving
conditions. If the vehicle has this
feature, see “Range Selection
Mode” underManual Mode on
page 9‑36.

Black plate (35,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-35
3 (Third):This position is also used
for normal driving. It reduces vehicle
speed more than D (Drive) without
using the brakes. You might choose
3 (Third) instead of D (Drive) when
driving on hilly, winding roads, when
towing a trailer, so there is less
shifting between gears and when
going down a steep hill.
2 (Second): This position reduces
vehicle speed even more than
3 (Third) without using the brakes.
You can use 2 (Second) on hills.
It can help control vehicle speed as
you go down steep mountain roads,
but then you would also want to use
the brakes off and on.
If you manually select 2 (Second) in
an automatic transmission, the
transmission will start in second
gear. You can use this feature for
reducing the speed of the rear
wheels when you are trying to start
the vehicle from a stop on slippery
road surfaces. 1 (First):
For the Hydra-Matic
4-Speed transmission this position
reduces vehicle speed even more
than 2 (Second) without using the
brakes. You can use it on very steep
hills, or in deep snow or mud. If the
shift lever is put in 1 (First) while the
vehicle is moving forward, the
transmission does not shift into first
gear until the vehicle is going slowly
enough.
For an Allison Transmission or
Hydra-Matic 6-Speed transmission,
this position reduces vehicle speed
without using the brakes. You can
use it for major/severe downgrades
and off-road driving where the
vehicle would otherwise accelerate
due to steepness of grade. When
you shift to 1 (First) it provides the
lowest gear appropriate to current
road speed and continues to
downshift as the vehicle slows,
eventually downshifting to
1 (First) gear.
Notice: Spinning the tires or
holding the vehicle in one place
on a hill using only the accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.
Normal Mode Grade Braking
Vehicles with a gasoline engine and
6-Speed automatic transmission
have Normal Mode Grade Braking
that is enabled when the vehicle is
started, but is not enabled in Range
Selection Mode. It assists in
maintaining desired vehicle speeds
when driving on downhill grades by
using the engine and transmission
to slow the vehicle. The first time
the system engages for each
ignition key cycle, a DIC message
will be displayed. See
Transmission
Messages on page 5‑44.
To disable or enable Normal Mode
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for

Black plate (36,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-36 Driving and Operating
three seconds. A DIC message
displays. SeeTransmission
Messages on page 5‑44.
For iother forms of grade braking,
see Tow/Haul Mode on page 9‑37
and Cruise Control on page 9‑56.
Manual Mode
Range Selection Mode
(Allison®Transmission or
Hydra-Matic®6-Speed
Transmission)
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the
vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears. To use this feature, do the following:
1. Move the shift lever to
M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column
shift lever, to select the desired
range of gears for current driving
conditions.
When M (Manual Mode) is selected
a number displays next to the M,
indicating the current gear.
This number is the highest gear that
can be used. However, the vehicle
can automatically shift to lower
gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until
the plus/minus button located on the
steering column lever is used to
change to the gear. Grade Braking is not available when
Range Selection Mode is active.
See
Tow/Haul Mode on page 9‑37.
While using Range Selection Mode,
Cruise Control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See Exhaust Brake in
the Duramax Diesel supplement.
Notice: Spinning the tires or
holding the vehicle in one place
on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.

Black plate (37,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-37
Low Traction Mode
If the vehicle has the Allison
Transmission, a 4-Speed automatic
transmission, or the Hydra-Matic
6-Speed Automatic Transmission
with the 6.0L engine, it has a Low
Traction Mode that assists in vehicle
acceleration when road conditions
are slippery, such as with ice or
snow. While the vehicle is at a stop,
select the second gear range using
Range Selection Mode. This will
limit torque to the wheels helping to
prevent the tires from spinning.
Tow/Haul Mode
4-Speed Automatic Transmission
6-Speed Automatic Transmission
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when driving down steep hills or
Mountain grades, towing, or hauling
heavy loads.
The selector button is located on the
end of the shift lever. Turn the Tow/
Haul Mode on and off by pressing
the button. When the Tow/Haul
Mode is enabled, a light on the
instrument panel cluster will
come on. See
Tow/Haul Mode Light on
page 5‑25 andHill and Mountain
Roads on page 9‑11 for more
information.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9‑89 for
more information.
Tow/Haul Mode Grade Braking
(6-Speed Automatic
Transmission)
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9‑36. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle.

Black plate (38,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
9-38 Driving and Operating
On vehicles with a gasoline engine,
to disable or enable Tow/Haul
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
three seconds. A DIC message will
be displayed. SeeTransmission
Messages on page 5‑44.
On vehicles with a diesel engine.
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See Towing Equipment on
page 9‑89 for more information.
For other forms of grade braking,
see Automatic Transmission on
page 9‑32 andCruise Control on
page 9‑56.Drive Systems
Four-Wheel Drive
If the vehicle has Four-Wheel Drive,
you can send the engine's driving
power to all four wheels for extra
traction. To get the most satisfaction
out of Four-Wheel Drive, you must
be familiar with its operation. Read
the following before using
Four-Wheel Drive. See the
appropriate text for the transfer case
in the vehicle.
Notice: Driving on clean, dry
pavement in Four-Wheel Drive
High or Four-Wheel Drive Low for
an extended period of time may
cause premature wear on the
vehicle's powertrain. Do not drive
on clean, dry pavement in
Four-Wheel Drive High or
Four-Wheel Drive Low for
extended periods of time.
While driving on clean dry pavement
and during tight turns, you may
experience vibration in the steering
system. If the vehicle has StabiliTrak
®,
shifting into Four-Wheel Drive Low
will turn Traction Control and
StabiliTrak off. See StabiliTrak
®
System on page 9‑53.
Front Axle
The front axle engages and
disengages automatically when you
shift the transfer case. Some delay
for the axle to engage or disengage
is normal.
Manual Transfer Case

Black plate (39,1)GMC Sierra Owner Manual - 2013 - crc - 8/14/12
Driving and Operating 9-39
The transfer case shift lever is on
the floor to the right of the driver.
Use this lever to shift into and out of
Four-Wheel Drive.
A Four-Wheel Drive indicator light
comes on when you shift into
four-wheel drive and the front axle
engages. SeeFour-Wheel-Drive
Light on page 5‑25.
Some delay between shifting and
when the indicator light comes on is
normal.
Recommended Transfer Case Settings
Driving Conditions Transfer Case Settings
2m 4m4n N
Normal YES Severe YES
Extreme YES
Vehicle in Tow* YES
*See Recreational Vehicle Towing on page 10‑87 orTowing the Vehicle on
page 10‑87.
Notice: Driving on clean, dry
pavement in four-wheel drive for
an extended period of time can
cause premature wear on the
vehicle's powertrain. Do not drive
on clean, dry pavement in
Four-Wheel Drive for extended
periods of time. 4
n(Four-Wheel Drive Low):
This
setting also engages the front axle
and delivers extra torque. You may
never need Four-Wheel Drive Low.
It sends maximum power to all
four wheels. You might choose
Four-Wheel Drive Low if you are
driving off-road in deep sand, deep
mud, deep snow, and while climbing
or descending steep hills.