
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
{ WarningShifting 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) ” under Four-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.
{ CautionFailure 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). { CautionIf 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 (100,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-100 Vehicle Care Tires Use a stiff brush with tire cleaner to
clean the tires.
{ CautionUsing petroleum-based tire
dressing products on the vehicle
may damage the paint finish and/
or tires. When applying a tire
dressing, always wipe off any
overspray from all painted
surfaces on the vehicle.
Wheels and Trim — Aluminum
or Chrome Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied. { CautionChrome wheels and other chrome
trim may be damaged if the
vehicle is not washed after driving
on roads that have been sprayed
with magnesium, calcium,
or sodium chloride. These
chlorides are used on roads for
conditions such as ice and dust.
Always wash the chrome with
soap and water after exposure.
{ Caution
To avoid surface damage, do not
use strong soaps, chemicals,
abrasive polishes, cleaners,
brushes, or cleaners that contain
acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
(Continued) Caution (Continued) automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
hook-up, binding, leaks, cracks,
chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
1500 Series vehicles, at least every
other oil change lubricate the outer
tie rod ends.

Black plate (101,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-1012500/3500 Series vehicles, at least
every other engine oil change
lubricate the upper and lower
control arm ball joints. Control arm
ball joints on 1500 series vehicles
are maintenance-free.
2500/3500 Series vehicles equipped
with steering linkage, at least every
other engine oil change lubricate the
tie rod ball joints, idler arm pivot
shaft bearings, idler arm socket, and
pitman arm socket.
{ CautionLubrication of applicable Steering/
Suspension points should not be
done unless temperature is -12°C
(10°F) or higher, or damage could
result.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance At least twice a year, spring and fall,
use plain water to flush dirt and
debris from the vehicle's underbody.
Your dealer or an underbody car
washing system can do this. If not
removed, rust and corrosion can
develop.
Sheet Metal Damage If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty. Finish Damage Quickly repair minor chips and
scratches with touch-up materials
available from your dealer to avoid
corrosion. Larger areas of finish
damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting Airborne pollutants can fall upon
and attack painted vehicle surfaces
causing blotchy, ring-shaped
discolorations, and small, irregular
dark spots etched into the paint
surface. Refer to “ Finish Care ”
previously in this section.
Interior Care To prevent dirt particle abrasions,
regularly clean the vehicle's interior.
Immediately remove any soils. Note
that newspapers or dark garments
that can transfer color to home
furnishings can also permanently
transfer color to the vehicle's
interior.

Black plate (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-4 Service and Maintenance .
Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care on page 10-96 . Replace
worn or damaged wiper blades.
See Wiper Blade Replacement
on page 10-35 ..
Check tire inflation pressures.
See Tire Pressure on
page 10-59 ..
Inspect tire wear. See Tire
Inspection on page 10-65 ..
Visually check for fluid leaks. .
Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter on
page 10-15 ..
Inspect brake system. .
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear
at least once a year. See
Exterior Care on page 10-96 .
Lubricate the suspension and steering components at least
every other oil change.
(If equipped with grease fittings) .
Check restraint system
components. See Safety System
Check on page 3-16 . .
Visually inspect fuel system for
damage or leaks. .
Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts. .
Lubricate body components. See
Exterior Care on page 10-96 ..
Check starter switch. See Starter
Switch Check on page 10-33 ..
Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check on
page 10-34 . .
Check ignition transmission lock.
See Ignition Transmission Lock
Check on page 10-34 . .
Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check on
page 10-34 . .
Check accelerator pedal for
damage, high effort, or binding.
Replace if needed. .
Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required. .
Inspect sunroof track and seal,
if equipped. See Sunroof on
page 2-22 . .
Verify spare tire key lock
operation and lubricate as
needed. See Tire Changing on
page 10-76 .

Black plate (10,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-10 Service and Maintenance Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road. .
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking. .
With a multi-point inspection,
your dealer can check the lamps
and note any concerns. Shocks and Struts
Shocks and struts help aid in control
for a smoother ride. .
Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear. .
As part of the multi-point
inspection, trained dealer
technicians can visually inspect
the shocks and struts for signs
of leaking, blown seals,
or damage, and can advise
when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money and fuel,
and can reduce the risk of tire
failure. .
Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord
or fabric showing through the rubber; cracks or cuts in the
tread or sidewall; or a bulge or
split in the tire. .
Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also
provide tire/wheel balancing
services to ensure smooth
vehicle operation at all speeds.
Your dealer sells and services
name brand tires.
Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle ’ s interior and
exterior, see Interior Care on
page 10-101 and Exterior Care on
page 10-96 .

Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-12 Service and Maintenance
Recommended Fluids, Lubricants, and Parts Recommended Fluids and Lubricants This maintenance section applies to vehicles with a gasoline engine. If the vehicle has a diesel engine and/or an
Allison Transmission, see the maintenance schedule section in the Duramax diesel supplement.
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.
Usage Fluid/Lubricant
Engine Oil Use only engine oil licensed to the dexos1 ®
specification of the proper SAE
viscosity grade. ACDelco dexos1 Synthetic Blend is recommended. See
Engine Oil on page 10-8 .
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL ®
coolant.
See Engine Coolant on page 10-18 .
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 19299818, in
Canada 19299819).
Windshield Washer Automotive windshield washer fluid that meets regional freeze protection
requirements.
Hydraulic Power Steering System
(HD Only) GM Power Steering Fluid (GM Part No. 89021185, in Canada 89021186).
Automatic Transmission (All except
6.2L with 8-Speed transmission) DEXRON ®
-VI Automatic Transmission Fluid.

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Customer Information 13-11Managing the Vehicle Damage
Repair Process In the event that the vehicle requires
damage repairs, GM recommends
that you take an active role in its
repair. If you have a pre-determined
repair facility of choice, take the
vehicle there, or have it towed there.
Specify to the facility that any
required replacement collision parts
be original equipment parts, either
new Genuine GM parts or recycled
original GM parts. Remember,
recycled parts will not be covered by
the GM vehicle warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits,
your insurance company may
initially value the repair using
aftermarket parts. Discuss this with
the repair professional, and insist on
Genuine GM parts. Remember,
if the vehicle is leased, you may be
obligated to have the vehicle
repaired with Genuine GM parts,
even if your insurance coverage
does not pay the full cost. If another party's insurance
company is paying for the repairs,
you are not obligated to accept a
repair valuation based on that
insurance company's collision policy
repair limits, as you have no
contractual limits with that company.
In such cases, you can have control
of the repair and parts choices as
long as the cost stays within
reasonable limits.
Service Publications
Ordering Information Service Manuals Service Manuals have the diagnosis
and repair information on the
engines, transmission, axle,
suspension, brakes, electrical,
steering, body, etc.
Service Bulletins
Service Bulletins give additional
technical service information
needed to knowledgeably service
General Motors cars and trucks. Each bulletin contains instructions
to assist in the diagnosis and
service of the vehicle.
Owner Information Owner publications are written
specifically for owners and intended
to provide basic operational
information about the vehicle. The
Owner Manual includes the
Maintenance Schedule for all
models.
In-Portfolio: Includes a Portfolio,
Owner Manual, and Warranty
Manual.
RETAIL SELL PRICE: $35.00 –
$40.00 (U.S.) plus handling and
shipping fees.
Without Pouch: Owner Manual only.
RETAIL SELL PRICE:
$25.00 (U.S.) plus handling and
shipping fees.

Black plate (5,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-5FlexFuel
E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-65
Floor Console Storage . . . . . . . . . . 4-3
Floor Mats . . . . . . . . . . . . . . . . . . .10-105
Fluid
Automatic
Transmission . . . . . . . 10-12, 10-15
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-27
Four-Wheel Drive
Transfer Case . . . . . . . . . . . . . . . 9-40
Power Steering . . . . . . . . . . . . . 10-24
Washer . . . . . . . . . . . . . . . . . . . . . 10-25
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 6-5
Bulb Replacement . . . . . . . . . . 10-37
Folding Mirrors . . . . . . . . . . . . . . . . 2-16
Forward Collision Alert
(FCA) System . . . . . . . . . . . . . . . . 9-59
Four-Wheel Drive . . . . . . . 9-40, 10-29
Four-Wheel-Drive Light . . . . . . . . 5-22
Frequency Statement
Radio . . . . . . . . . . . . . . . . . . . . . . . 13-12
Front Axle . . . . . . . . . . . . . . . . . . . . 10-30 Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Front Seats
Heated and Cooled . . . . . . . . . . . . 3-7
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Additives . . . . . . . . . . . . . . . . . . . . . 9-64
Economy Driving . . . . . . . . . . . . . 1-21
Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . 9-67
Filling the Tank . . . . . . . . . . . . . . . 9-66
Foreign Countries . . . . . . . . . . . . 9-64
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Low Fuel Warning Light . . . . . . . 5-25
Management, Active . . . . . . . . . . 9-32
Requirements, California . . . . . 9-64
System Messages . . . . . . . . . . . . 5-35
Full-Size Spare Tire . . . . . . . . . . 10-86
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . 10-41
Instrument Panel
Fuse Block . . . . . . . . . 10-45, 10-48 G Garage Door Opener . . . . . . . . . . 5-49
Programming . . . . . . . . . . . . . . . . . 5-49
Gauges
Engine Coolant
Temperature . . . . . . . . . . . . . . . . 5-13
Engine Oil Pressure . . . . . . . . . . 5-12
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
Odometer . . . . . . . . . . . . . . . . . . . . . 5-11
Speedometer . . . . . . . . . . . . . . . . . 5-11
Tachometer . . . . . . . . . . . . . . . . . . . 5-11
Transmission Temperature . . . . 5-14
Trip Odometer . . . . . . . . . . . . . . . . 5-11
Voltmeter . . . . . . . . . . . . . . . . . . . . . 5-15
Warning Lights and
Indicators . . . . . . . . . . . . . . . . . . . . 5-8
General Information
Service and Maintenance . . . . . 11-1
Towing . . . . . . . . . . . . . . . . . . . . . . . . 9-68
Vehicle Care . . . . . . . . . . . . . . . . . . 10-2
Glass Replacement . . . . . . . . . . . 10-35
Glove Box . . . . . . . . . . . . . . . . . . . . . . 4-1
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . 13-5