towing GMC SIERRA DENALI 2017 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 253Trailer Towing General Towing
Information . . . . . . . . . . . . . . . . . . 320
Driving Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 320
Trailer Towing . . . . . . . . . . . . . . . . 323
Towing Equipment . . . . . . . . . . . . 340
Trailer Sway Control (TSC) . . . 349
Conversions and Add-Ons Add-On Electrical
Equipment . . . . . . . . . . . . . . . . . . 350
Adding a Snow Plow or Similar
Equipment . . . . . . . . . . . . . . . . . . 350
Pickup Conversion to
Chassis Cab . . . . . . . . . . . . . . . . 354 Driving Information Distracted Driving Distraction comes in many forms
and can take your focus from the
task of driving. Exercise good
judgment and do not let other
activities divert your attention away
from the road. Many local
governments have enacted laws
regarding driver distraction. Become
familiar with the local laws in
your area.
To avoid distracted driving, keep
your eyes on the road, keep your
hands on the steering wheel, and
focus your attention on driving.
.
Do not use a phone in
demanding driving situations.
Use a hands-free method to
place or receive necessary
phone calls.
.
Watch the road. Do not read,
take notes, or look up
information on phones or other
electronic devices. .
Designate a front seat
passenger to handle potential
distractions.
.
Become familiar with vehicle
features before driving, such as
programming favorite radio
stations and adjusting climate
control and seat settings.
Program all trip information into
any navigation device prior to
driving.
.
Wait until the vehicle is parked
to retrieve items that have fallen
to the floor.
.
Stop or park the vehicle to tend
to children.
.
Keep pets in an appropriate
carrier or restraint.
.
Avoid stressful conversations
while driving, whether with a
passenger or on a cell phone.
{ Warning
Taking your eyes off the road too
long or too often could cause a
crash resulting in injury or death.
Focus your attention on driving.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 265causes 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. See
Towing the Vehicle 0 439 . Recovery
hooks can be used, if the vehicle
has them.
Recovery Hooks
{ WarningNever pull on recovery hooks
from the side. The hooks could
break and you and others could
be injured. When using recovery
hooks, always pull the vehicle
from the front. CautionDo not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
There are recovery hooks at the
front of the vehicle. Use them if the
vehicle is stuck off-road and needs
to be pulled some place to continue
driving. Vehicle Load Limits It is very important to know how
much weight the vehicle can
carry. This weight is called the
vehicle capacity weight and
includes the weight of all
occupants, cargo, and all
nonfactory-installed options.
Two labels on the vehicle may
show how much weight it was
designed to carry: the Tire and
Loading Information label and
the Certification/Tire label.
{ Warning
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
This can cause systems to
break and change the way the
vehicle handles. This could
cause loss of control and a
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 267That weight may not safely
exceed the available cargo
and luggage load capacity
calculated in Step 4.6.
If your vehicle will be towing
a trailer, load from your
trailer will be transferred to
your vehicle. Consult this
manual to determine how
this reduces the available
cargo and luggage load
capacity of your vehicle. ”
See Trailer Towing 0 323 for
important information on towing
a trailer, towing safety rules, and
trailering tips. Example 1
1. Vehicle Capacity Weight for
Example 1 = (453 kg)
(1,000 lb)
2. Subtract Occupant Weight
@ 68 kg (150 lb) × 2 =
136 kg (300 lb)
3. Available Occupant and
Cargo Weight = 317 kg
(700 lb) Example 2
1. Vehicle Capacity Weight for
Example 2 = 453 kg
(1,000 lb)
2. Subtract Occupant Weight
@ 68 kg (150 lb) × 5 =
340 kg (750 lb)
3. Available Cargo Weight =
113 kg (250 lb)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 273
Starting and
Operating New Vehicle Break-In CautionThe 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 mi).
.
Do not drive at any one
constant speed, fast or slow,
for the first 805 km (500 mi).
Do not make full-throttle
starts. Avoid downshifting to
brake or slow the vehicle.
.
Avoid making hard stops for
the first 322 km (200 mi) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
(Continued) Caution (Continued) 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
0 323 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 If equipped, the position of the
throttle and brake pedals can be
changed.
The pedals can only be adjusted
when the vehicle is in P (Park). The switch used to adjust the
pedals is on the center stack, below
the climate controls.
Lift the switch up to move the
pedals closer to your body. Press
the switch down to move the
pedals away.
Before you start driving, fully press
the brake pedal to confirm the
adjustment is right for you.
The vehicle may have a memory
function, which lets pedal settings
be saved and recalled. See Memory
Seats 0 60 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 279Warning (Continued) it overheat and cause a fire,
property damage, electric
shock, and injury.
.
Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater
cord and thermostat
damage could occur.
.
While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
.
Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts. 4. Before starting the engine, be
sure to unplug and store the
cord as it was before to keep it
away from moving engine
parts. If you do not, it could be
damaged.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{ WarningIt 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 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, use the steps
that follow. With four-wheel drive,
if the transfer case is in
(Continued) Warning (Continued) 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. If towing a
trailer, see Driving Characteristics
and Towing Tips 0 320 .
1. Hold the brake pedal down,
then set the parking brake.
See Parking Brake 0 297 .
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 (if
equipped) 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).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
282 Driving and Operating
Engine Exhaust
{ WarningEngine exhaust contains carbon
monoxide (CO), which cannot be
seen or smelled. Exposure to CO
can cause unconsciousness and
even death.
Exhaust may enter the vehicle if:
.
The vehicle idles in areas
with poor ventilation
(parking garages, tunnels,
deep snow that may block
underbody airflow or tail
pipes).
.
The exhaust smells or
sounds strange or different.
.
The exhaust system leaks
due to corrosion or damage.
.
The vehicle exhaust system
has been modified,
damaged, or improperly
repaired.
(Continued) Warning (Continued) .
There are holes or openings
in the vehicle body from
damage or aftermarket
modifications that are not
completely sealed.
If unusual fumes are detected or
if it is suspected that exhaust is
coming into the vehicle:
.
Drive it only with the
windows completely down.
.
Have the vehicle repaired
immediately.
Never park the vehicle with the
engine running in an enclosed
area such as a garage or a
building that has no fresh air
ventilation. 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.
See Shifting Into Park 0 279 and
Engine Exhaust 0 282 .
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips 0 320 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 283
Automatic
Transmission If equipped, there is an electronic
shift lever position indicator within
the instrument 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.
Heavy-Duty 6-Speed Automatic
Transmission Shown, Others
Similar
See “ Range Selection Mode ” under
Manual Mode 0 286 .
P : 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, 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 0 279 .
{ WarningIt 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 0 279 and
Driving Characteristics and
Towing Tips 0 320 .{ WarningIf 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 N (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
N (Neutral). See Shifting Into Park
0 279 .
R : Use this gear to back up.
CautionShifting 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
284 Driving and Operating 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 0 264 .
N : 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.
{ WarningShifting 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. CautionShifting 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.
D : 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.
Use D (Drive) and Tow/Haul Mode
when towing a trailer, carrying a
heavy load, driving on steep hills, or driving off-road. 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 0 256 .
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
286 Driving and Operating
Manual Mode Range Selection Mode
If equipped, Range Selection Mode
helps control the vehicle's
transmission and vehicle speed
while driving downhill or towing a
trailer by letting you select a desired
range of gears.
To use this feature:
1. Move the shift lever to
L (Manual Mode).
2. Press the plus/minus buttons
on the shift lever to select the
desired range of gears for
current driving conditions. With an 8-speed automatic
transmission, hold the plus/minus
buttons on the shift lever to select
the highest or lowest range
available for the current vehicle
speed.
When the shift lever is moved from
D (Drive) to L (Manual Mode), a
number displays next to the L,
indicating the current transmission
range.
This number is the highest gear that
the transmission will command while
operating in L (Manual Mode). All
gears below that number are
available. As driving conditions
change, the transmission can
automatically shift to lower gears.
For example, when L5 is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the
transmission, but 6 (Sixth) cannot be
used until the plus/minus button on
the shift lever is used to change to
the range. In vehicles with gasoline engines,
when the shift lever is moved from
D (Drive) to L (Manual Mode), a
downshift may occur. The gear that
the transmission is operating in
when the shift lever is moved from
D (Drive) to L (Manual Mode)
determines if a downshift occurs.
See the following chart.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
288 Driving and Operating Low Traction Mode If equipped, Low Traction Mode
assists in vehicle acceleration when
road conditions are slippery, such
as with ice or snow. While the
vehicle is at a stop, select L2 using
Range Selection Mode. This will
limit torque to the wheels and help
to prevent the tires from spinning.
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling. This provides increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, when towing, or when
hauling heavy loads.
The selector button is 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
cluster will come on.
For an eAssist vehicle, the Stop/
Start function will become
unavailable when Tow/Haul Mode is
active.
For an eAssist vehicle, the
Regenerative Braking functionality is
disabled when using the Tow/Haul
Mode. See the eAssist supplement.
See Tow/Haul Mode Light 0 147 and
Hill and Mountain Roads 0 262 .
Also see “ Tow/Haul Mode ” under
Towing Equipment 0 340 .
Tow/Haul Mode Grade Braking
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 0 286 .
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.
If equipped, 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 five seconds. When the button is
released, the requested mode
change is made. A DIC message is
displayed. See Transmission
Messages 0 164 .
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 0 340 .
For other forms of grade braking,
see Automatic Transmission 0 283
and Cruise Control 0 302 .