
Black plate (78,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-78 Vehicle Care
3. Insert the hoist end (openend) (10) of the extension
through the hole (9) in the rear
bumper.
Do not use the chiseled end of
the wheel wrench.
Be sure the hoist end of the
extension (10) connects to the
hoist shaft. The ribbed square
end of the extension is used to
lower the spare tire.
4. Turn the wheel wrench counterclockwise to lower the
spare tire to the ground.
Continue to turn the wheel
wrench until the spare tire can
be pulled out from under the
vehicle.
5. Pull the spare tire out from under the vehicle.
6. Tilt the tire toward the vehicle
with some slack in the cable to
access the tire/wheel retainer.
Tilt the retainer and pull it
through the center of the wheel
along with the cable and spring.
7. Put the spare tire near the flat tire.
Removing the Flat Tire and
Installing the Spare Tire
Use the following pictures and
instructions to remove the flat tire
and raise the vehicle.
1. Jack
2. Wheel Blocks
3. Jack Handle
4. Jack Handle Extension
5. Wheel Wrench
The tools you will be using include
the jack (1), the wheel blocks (2),
the jack handle (3), the jack handle
extensions (4), and the wheel
wrench (5).
1. Do a safety check beforeproceeding. See If a Tire Goes
Flat on page 10-74 for more
information.

Black plate (82,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-82 Vehicle Care
7. Remove all the wheel nuts andtake off the flat tire.
{Warning
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, a cloth or a paper
(Continued)
Warning (Continued)
towel can be used; however, use
a scraper or wire brush later to
remove all rust or dirt.
8. Remove any rust or dirt from thewheel bolts, mounting surfaces,
and spare wheel.
9. Install the spare tire.
{Warning
Never use oil or grease on bolts
or nuts because the nuts might
come loose. The vehicle's wheel
could fall off, causing a crash.
10. Put the wheel nuts back on with the rounded end of the
nuts toward the wheel.
11. Tighten each wheel nut by hand. Then use the wheel
wrench to tighten the nuts until
the wheel is held against
the hub.
12. Turn the wheel wrench counterclockwise to lower the
vehicle. Lower the jack
completely.
{Warning
If wheel studs are damaged, they
can break. If all the studs on a
wheel broke, the wheel could
(Continued)

Black plate (84,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-84 Vehicle Care
Repeat this service whenever you
have a tire removed or serviced.
SeeCapacities and Specifications
on page 12-2.
When reinstalling the regular wheel
and tire, also reinstall either the
center cap, or bolt-on hub cap,
depending on what the vehicle is
equipped with. For center caps,
place the cap on the wheel and tap
it into place until it seats flush with
the wheel. The cap only goes on
one way. Be sure to line up the tab
on the center cap with the
indentation on the wheel. For
bolt-on hub caps, align the plastic
nut caps with the wheel nuts and
then tighten by hand. Then use the
wheel wrench to tighten.Storing a Flat or Spare Tire
and Tools
{Warning
Storing a jack, a tire, or other
equipment in the passenger
compartment of the vehicle could
cause injury. In a sudden stop or
collision, loose equipment could
strike someone. Store all these in
the proper place.
{Caution
Storing an aluminum wheel with a
flat tire under your vehicle for an
extended period of time or with
the valve stem pointing up can
damage the wheel. Always stow
the wheel with the valve stem
pointing down and have the
wheel/tire repaired as soon as
possible. Store the tire under the rear of the
vehicle in the spare tire carrier.
1. Spare Tire (Valve Stem
Pointed Down)
2. Tire/Wheel Retainer
3. Hoist Cable
4. Hoist Assembly
5. Hoist Shaft
6. Jack Handle Extensions
7. Wheel Wrench
8. Spare Tire Lock (If Equipped)
9. Hoist Shaft Access Hole
10. Hoist End of Extension Tool

Black plate (86,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-86 Vehicle Care
To store the jack and jack tools:
1. Wing Nut Retaining WheelBlocks
2. Wheel Blocks
3. Wing Nut Retaining Tool Kit
4. Wheel Wrench and Extensions
5. Tool Bag
6. Jack Mounting Bracket
7. Jack
8. Bolt Retaining Wheel Blocks
1. Put the tools (4) in the tool bag (5) and place them in the
retaining bracket (3). 2. Tighten down the wing nut (3).
3. Assemble the wheel blocks (2)
and jack (7) together with the
wing nut (1) and retaining
bolt (8).
4. Position the jack (7) in the mounting bracket (6). Position
the holes in the base of the
jack (7) onto the pin in the
mounting bracket (6).
5. Return them to their original location in the vehicle. See
“Removing the Spare Tire and
Tools.”
Full-Size Spare Tire
If this vehicle came with a full-size
spare tire, it was fully inflated when
new, however, it can lose air over
time. Check the inflation pressure
regularly. See Tire Pressure on
page 10-59 andVehicle Load Limits
on page 9-15. For instructions on
how to remove, install, or store a
spare tire, see Tire Changing on
page 10-76. If equipped with a temporary use
full-size spare tire, it is indicated on
the tire sidewall. See
Tire Sidewall
Labeling on page 10-52. This spare
tire should not be driven on over
112 km/h (70 mph), or 88 km/h
(55 mph) when pulling a trailer, at
the proper inflation pressure.
Repair and replace the road tire as
soon as it is convenient, and stow
the spare tire for future use.
{Caution
If the vehicle has four-wheel drive
and a different size spare tire is
installed, do not drive in
four-wheel drive until the flat tire
is repaired and/or replaced. The
vehicle could be damaged and
the repairs would not be covered
by the warranty. Never use
four-wheel drive when a different
size spare tire is installed on the
vehicle.

Black plate (91,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-91
6.6L
‐ To the negative (−) post on
the auxiliary battery, on the
vehicle with the dead battery.
11. Start the vehicle with the good battery and run the engine for a
while.
12. Try to start the vehicle that had the dead battery. If it will not
start after a few tries, it
probably needs service.
{Caution
If the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
Towing the Vehicle
{Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Have the vehicle towed on a flatbed
car carrier. A wheel lift tow truck
could damage the vehicle.
Consult your dealer or a
professional towing service if the
disabled vehicle must be towed.
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of
recreational vehicle towing are
dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly

Black plate (92,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-92 Vehicle Care
towing is towing the vehicle with two
wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle
manufacturer’s instructions. See
your dealer or trailering professional
for additional advice and equipment
recommendations.
{Caution
Use of a shield mounted in front
of the vehicle grille could restrict
airflow and cause damage to the
transmission. The repairs would
not be covered by the vehicle
warranty. If using a shield, only
use one that attaches to the
towing vehicle.
Dinghy Towing
Two-Wheel-Drive Vehicles
{Caution
If the two-wheel-drive vehicle is
towed with all four wheels on the
ground, the drivetrain
components could be damaged.
The repairs would not be covered
by the vehicle warranty. Two-wheel-drive vehicles should not
be towed with all four wheels on the
ground.
Four-Wheel-Drive VehiclesOnly dinghy tow four-wheel-drive
vehicles with a two-speed transfer
case that have an N (Neutral) and a
Four-Wheel Drive Low (4 (
n) setting.

Black plate (93,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-93
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral).
Follow these steps to dinghy tow:
1. Position the vehicle being towed behind the tow vehicle, facing
forward and on a level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive on page 9-40 for the
proper procedure. Check that
the vehicle is in N (Neutral) by shifting the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. With the transmission in D (Drive), turn the ignition to ACC/
ACCESSORY.
{Caution
Failure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. Disconnect the negative battery cable at the battery and secure
the nut and bolt. Cover the
negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to P (Park).
{Caution
If the steering column is locked,
vehicle damage may occur.
8. Move the steering wheel to make sure the steering column
is unlocked.
9. Release the parking brake.
10. Keep the ignition key in the towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle:
1. Park on a level surface.
2. Set the parking brake, shift the transmission to P (Park), and
move the ignition key to OFF.
3. Connect the battery.
4. Apply the brake pedal.

Black plate (94,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-94 Vehicle Care
5. Start the engine, then shift thetransfer case out of N (Neutral)
to Two-Wheel Drive High. See
Four-Wheel Drive for directions
on shifting out of N (Neutral).
6. Check that the vehicle is in Two-Wheel Drive High by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be
movement of the vehicle while
shifting.
7. Shift the transmission to P (Park) and turn off the ignition.
8. Disconnect the vehicle from the tow vehicle.
9. Release the parking brake.
10. Reset any lost presets.
The outside temperature
display will default to 32°F but
will reset with normal usage.Dolly Towing
Front Towing (Front Wheels Off
the Ground) –Two-Wheel-Drive
Vehicles
{Caution
If a two-wheel-drive vehicle is
towed with the rear wheels on the
ground, the transmission could be
damaged. The repairs would not
be covered by the vehicle
(Continued)
Caution (Continued)
warranty. Never tow the vehicle
with the rear wheels on the
ground.
Two-wheel-drive vehicles should not
be towed with the rear wheels on
the ground. Two-wheel-drive
transmissions have no provisions
for internal lubrication while being
towed.
To dolly tow a two-wheel-drive
vehicle, the vehicle must be towed
with the rear wheels on the dolly.
See “Rear Towing (Rear Wheels Off
the Ground)” later in this section.