GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
304 Driving and Operating
{Warning
Attempting to refuel without using
the funnel adapter may cause fuel
spillage and damage the capless
fuel system. This could cause a
fire and you or others could be
badly burned and the vehicle
could be damaged.
3. Remove and clean the funnel adapter and return to the
storage location.
Filling a Portable Fuel
Container
{Warning
Filling a portable fuel container
while it is in the vehicle can cause
fuel vapors that can ignite either
by static electricity or other
means. You or others could be
badly burned and the vehicle
could be damaged. Always:
(Continued)
Warning (Continued)
.Use approved fuel
containers.
. Remove the container from
the vehicle, trunk, or pickup
bed before filling.
. Place the container on the
ground.
. Place the nozzle inside the
fill opening of the container
before dispensing fuel, and
keep it in contact with the fill
opening until filling is
complete.
. Fill the container no more
than 95% full to allow for
expansion.
. Do not smoke, light
matches, or use lighters
while pumping fuel.
. Avoid using cell phones or
other electronic devices.
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle 0422. For
towing the vehicle behind another
vehicle such as a motor home, see
Recreational Vehicle Towing 0423.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.
Become familiar with the state
and local laws that apply to
trailer towing.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 325
Vehicle SeriesTrailer WeightWeight-Distributing Hitch
Usage Hitch Distribution
1500 Up to 3 175 kg (7,000 lb) OptionalRefer to trailer
manufacturer ’s
recommendation
1500 Over 3 175 kg (7,000 lb) Required50%
2500/3500 Up to 9 080 kg (20,000 lb) OptionalRefer to trailer
manufacturer ’s
recommendation
1. Front of Vehicle
2. Body to Ground Distance
When using a weight-distributing
hitch, measure distance (2) before
coupling the trailer to the hitch ball.
Measure the height again after the
trailer is coupled and adjust the
spring bars so the distance (2) is as
close as possible to halfway
between the two measurements.
Fifth-Wheel and Gooseneck
Trailering
Fifth-wheel and gooseneck trailers
can be used with many pickup
models. These trailers place a
larger percentage of the weight
(kingpin weight) on the tow vehicle than conventional trailers. Make
sure this weight does not cause the
vehicle to exceed GAWR or GVWR.
Fifth-wheel or gooseneck kingpin
weight should be 15 to 25% of the
trailer weight up to the maximum
amount specified in the trailering
chart for the vehicle. See
“Weight of
the Trailer” underTrailer
Towing 0307.
The hitch should be located in the
pickup bed so that its centerline is
over or slightly in front of the rear
axle. Take care that it is not so far
forward that it will contact the back
of the cab in sharp turns. This is
especially important for short box
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/6/16
Driving and Operating 327
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
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.
Heavy-Duty Trailer Wiring Harness
Package
For vehicles equipped with
heavy-duty trailering, the harness
connector is mounted in the bumper.
For vehicles with the fifth wheel/
gooseneck trailer package, the
harness connector is mounted on
the inside of the pickup bed behind
the rear wheel.
The seven-wire harness contains
the following trailer circuits:
.Green/Violet: Right Stop/Turn
Signal
. Yellow/Gray: Left Stop/Turn
Signal
. Gray/Brown: Taillamps/Parking
Lamps
. White: Ground
. White/Green: Back-up Lamps .
Red/Green: Battery Feed
. Dark Blue: Trailer Brake
To help charge a remote
(non-vehicle) battery, press the Tow/
Haul Mode button at the end of the
shift lever. If the trailer is too light for
Tow/Haul Mode, turn on the
headlamps to help charge the
battery.
Camper/Fifth-Wheel Trailer Wiring
Package
For vehicles without the fifth wheel/
gooseneck tralier package,
seven-wire camper harness is under
the rear bumper, attached to the
frame near the rear crossmember.
A connector must be added to the
wiring harness that connects to the
camper.
The harness contains the following
camper/trailer circuits:
. Green/Violet: Right Stop/Turn
Signal
. Yellow/Gray: Left Stop/Turn
Signal
. Gray/Brown: Taillamps/Parking
Lamps
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
328 Driving and Operating
.White: Ground
. White/Green: Back-up Lamps
. Red/Green: Battery Feed
. Dark Blue: Trailer Brake
If the vehicle is equipped with the
heavy-duty trailering option, see
“Heavy-Duty Trailer Wiring Harness
Package” earlier in this section.
When the camper-wiring harness is
ordered without the heavy-duty
trailering package, a seven-wire
harness with a seven-pin connector
is at the rear of the vehicle and is
tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller.
The harness should be installed by
your dealer or a qualified service
center.
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
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. See
Tow/Haul
Mode 0273.
Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross
Combined Weight Rating (GCWR).
See “Weight of the Trailer” under
Trailer Towing 0307. 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 benefit to the
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 333
A 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.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
being towed. If the vehicle is towing
a trailer and the TSC detects that
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If the vehicle
is equipped with the Integrated
Trailer Brake Control (ITBC) system,
and the trailer has the electric
actuated brake system, StabiliTrak
may also apply the trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on theinstrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. See
Traction Control/
Electronic Stability Control 0284.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment 0324 for trailer ratings
and hitch setup
recommendations. Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and
Modifications
0341.
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
334 Driving and Operating
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light)
0 133. A device connected to the
DLC —such as an aftermarket
fleet or driver-behavior tracking
device —may interfere with
vehicle systems. This could affect
vehicle operation and cause a
crash. Such devices may also
access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 079 and Adding Equipment
to the Airbag-Equipped
Vehicle 079.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.
Adding a Snow Plow or
Similar Equipment
Caution
Do not exceed 72 km/h (45 mph)
with a snow plow mounted to the
vehicle. The vehicle could
overheat and be damaged.
Before installing a snow plow on the
vehicle, follow these guidelines:
Caution
If the vehicle does not have the
snow plow prep package, RPO
VYU, adding a plow can damage
the vehicle, and the repairs would
not be covered by the vehicle
warranty. Unless the vehicle was
built to carry a snow plow, do not
add one to the vehicle. If the
vehicle has RPO VYU, then the
payload the vehicle can carry will
be reduced when a snow plow is
installed. The vehicle can be (Continued)
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 339
Vehicle Care
General Information
General Information . . . . . . . . . . 340
California Proposition65 Warning . . . . . . . . . . . . . . . . . 340
California Perchlorate Materials Requirements . . . . . 341
Accessories and Modifications . . . . . . . . . . . . . . . . 341
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 342
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 342
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 343
Engine Oil . . . . . . . . . . . . . . . . . . . . 348
Engine Oil Life System . . . . . . . 351
Automatic Transmission Fluid (6 Speed Transmission) . . . . . 352
Automatic Transmission Fluid (8 Speed Transmission) . . . . . 354
Engine Air Cleaner/Filter . . . . . . 355
Cooling System . . . . . . . . . . . . . . 356
Engine Coolant . . . . . . . . . . . . . . . 357
Engine Overheating . . . . . . . . . . 360
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 362
Engine Fan . . . . . . . . . . . . . . . . . . . 362 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 363
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 363
Washer Fluid . . . . . . . . . . . . . . . . . 363
Brakes . . . . . . . . . . . . . . . . . . . . . . . 364
Brake Fluid . . . . . . . . . . . . . . . . . . . 365
Battery - North America . . . . . . 366
Four-Wheel Drive . . . . . . . . . . . . . 367
Front Axle . . . . . . . . . . . . . . . . . . . . 368
Rear Axle . . . . . . . . . . . . . . . . . . . . 368
Noise Control System . . . . . . . . 370
Starter Switch Check . . . . . . . . . 371
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 371
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 371
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 371
Wiper Blade Replacement . . . . 372
Glass Replacement . . . . . . . . . . 372
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 373
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 373
Halogen Bulbs . . . . . . . . . . . . . . . . 373
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 373 LED Lighting . . . . . . . . . . . . . . . . . 373
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 374
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 375
Replacement Bulbs . . . . . . . . . . . 375
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 376
Electrical System Overload . . . 376
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 376
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 376
Instrument Panel Fuse Block
(Right) . . . . . . . . . . . . . . . . . . . . . . 379
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 381
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 383
All-Season Tires . . . . . . . . . . . . . . 384
Winter Tires . . . . . . . . . . . . . . . . . . 384
Low-Profile Tires . . . . . . . . . . . . . 385
All-Terrain Tires . . . . . . . . . . . . . . . 385
Tire Sidewall Labeling . . . . . . . . 385
Tire Designations . . . . . . . . . . . . . 388
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 389
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 355
equipped with a transmission fluid
level dipstick. There is a special
procedure for checking and
changing the transmission fluid in
these vehicles. Because this
procedure is difficult, this should be
done at the dealer. Contact the
dealer for additional information or
the procedure can be found in the
service manual. SeeService
Publications Ordering
Information 0466.
Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants 0447.
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 438. Be sure to use the transmission fluid listed in
Recommended Fluids and
Lubricants
0447.
Engine Air Cleaner/Filter
If the vehicle has a diesel engine,
see “8-Cylinder Pickup Models”
under “Engine Air Cleaner/Filter” in
the Duramax diesel supplement for
the correct inspection and
replacement procedures.
The engine air cleaner/filter is on
the passenger side of the engine
compartment. See Engine
Compartment Overview 0343.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air filter, see
Maintenance Schedule 0438.
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/
filter, make sure that the engine air cleaner/filter housing and nearby
components are free of dirt and
debris. Remove the engine air
cleaner/filter. Lightly tap and shake
the engine air cleaner/filter (away
from the vehicle), to release loose
dust and dirt. Inspect the engine air
cleaner/filter for damage, and
replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:
1. Screws
2. Electrical Connectors