2015 GMC SIERRA DENALI ECU

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
2015 GMC Sierra Denali Owner Manual MIn Brief . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Instrument Panel . . . . . . . . . . . . . . 1-2
Initial Drive Information . . . . . . . . 1-4
Vehicle Features . . . . . . . . . . . . . 1-16
Performance and
Maintenance . . . . . . . . . . . . . . . . 1-20
Keys, Doors, and
Windows . . . . . . . . . . . . . . . . . . . . 2-1
Keys and Locks . . . . . . . . . . . . . . . 2-1
Doors . . . . . . . . . . . . . . . . . . . . . . . . 2-10
Vehicle Security . . . . . . . . . . . . . . 2-11
Exterior Mirrors . . . . . . . . . . . . . . . 2-14
Interior Mirrors . . . . . . . . . . . . . . . . 2-19
Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Roof . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22
Seats and Restraints . . . . . . . . . 3-1
Head Restraints . . . . . . . . . . . . . . . 3-2
Front Seats . . . . . . . . . . . . . . . . . . . . 3-3
Rear Seats . . . . . . . . . . . . . . . . . . . . 3-9
Safety Belts . . . . . . . . . . . . . . . . . . 3-10
Airbag System . . . . . . . . . . . . . . . . 3-17
Child Restraints . . . . . . . . . . . . . . 3-30 Storage . . . . . . . . . . . . . . . . . . . . . . . 4-1
Storage Compartments . . . . . . . . 4-1
Additional Storage Features . . . 4-3
Instruments and Controls . . . . 5-1
Controls . . . . . . . . . . . . . . . . . . . . . . . 5-2
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . 5-8
Information Displays . . . . . . . . . . 5-27
Vehicle Messages . . . . . . . . . . . . 5-31
Vehicle Personalization . . . . . . . 5-42
Universal Remote System . . . . 5-49
Lighting . . . . . . . . . . . . . . . . . . . . . . . 6-1
Exterior Lighting . . . . . . . . . . . . . . . 6-1
Interior Lighting . . . . . . . . . . . . . . . . 6-6
Lighting Features . . . . . . . . . . . . . . 6-8
Infotainment System . . . . . . . . . 7-1
Introduction . . . . . . . . . . . . . . . . . . . . 7-1 Climate Controls . . . . . . . . . . . . . 8-1
Climate Control Systems . . . . . . 8-1
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 8-4
Maintenance . . . . . . . . . . . . . . . . . . . 8-5
Driving and Operating . . . . . . . . 9-1
Driving Information . . . . . . . . . . . . . 9-2
Starting and Operating . . . . . . . 9-23
Engine Exhaust . . . . . . . . . . . . . . 9-32
Automatic Transmission . . . . . . 9-33
Drive Systems . . . . . . . . . . . . . . . . 9-40
Brakes . . . . . . . . . . . . . . . . . . . . . . . 9-46
Ride Control Systems . . . . . . . . 9-49
Cruise Control . . . . . . . . . . . . . . . . 9-52
Driver Assistance Systems . . . 9-55
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63
Trailer Towing . . . . . . . . . . . . . . . . 9-68
Conversions and Add-Ons . . . 9-88
Vehicle Care . . . . . . . . . . . . . . . . . 10-1
General Information . . . . . . . . . . 10-2
Vehicle Checks . . . . . . . . . . . . . . . 10-3
Headlamp Aiming . . . . . . . . . . . 10-36
Bulb Replacement . . . . . . . . . . 10-36
Electrical System . . . . . . . . . . . . 10-40
Wheels and Tires . . . . . . . . . . . 10-50

Black plate (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-19Vehicles with Bench Seats .
One on the center stack below
the climate control system. .
One or two in the storage area
on the bench seat.
Lift the cover to access and replace
when not in use.
See Power Outlets on page 5-5 .
Universal Remote System
If equipped with the Universal
Remote system, these buttons will
be in the front overhead console.
This system provides a way to
replace up to three remote control
transmitters used to activate
devices such as garage door
openers, security systems, and
home automation devices. See Universal Remote System on
page 5-49 .
Sunroof
If equipped, the sunroof only
operates when the ignition is in
ACC/ACCESSORY or ON/RUN,
or when Retained Accessory Power
(RAP) is active. See Retained
Accessory Power (RAP) on
page 9-29 . Vent: From the closed position,
press the rear of the TILT switch to
vent the sunroof.
Manual-Open/Manual-Close: To
open the sunroof, press and hold
the rear of the SLIDE switch until
the sunroof reaches the desired
position. Press and hold the front of
the SLIDE switch to close it.
Express-Open/Express-Close: To
express-open the sunroof, fully
press and release the rear of the
SLIDE switch until the sunroof
reaches the desired position. To
express-close the sunroof, fully
press and release the front of the
SLIDE switch. Press the switch
again to stop it.
When the sunroof is opened, an air
deflector will automatically raise.
The air deflector will retract when
the sunroof is closed.

Black plate (22,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
1-22 In Brief .
Avoid idling the engine for long
periods of time. .
When road and weather
conditions are appropriate, use
cruise control. .
Always follow posted speed
limits or drive more slowly when
conditions require. .
Keep vehicle tires properly
inflated. .
Combine several trips into a
single trip. .
Replace the vehicle's tires with
the same TPC Spec number
molded into the tire's sidewall
near the size. .
Follow recommended scheduled
maintenance.
Roadside Assistance
Program U.S.: 1-888-881-3302
TTY Users (U.S. Only):
1-888-889-2438 Canada: 1-800-268-6800
New GMC owners are automatically
enrolled in the Roadside Assistance
Program.
See Roadside Assistance Program
on page 13-5 .
OnStar ®
This vehicle may be equipped with a
comprehensive, in-vehicle system
that can connect to a live OnStar
Advisor for Emergency, Security,
Navigation, Connection, and
Diagnostic Services. OnStar
services may require a paid
subscription. See OnStar Overview
on page 14-1 .

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-1
Keys, Doors, and
Windows Keys and Locks Keys . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Remote Keyless Entry (RKE)
System . . . . . . . . . . . . . . . . . . . . . . 2-4
Remote Keyless Entry (RKE)
System Operation . . . . . . . . . . . 2-4
Remote Vehicle Start . . . . . . . . . 2-7
Door Locks . . . . . . . . . . . . . . . . . . . 2-8
Power Door Locks . . . . . . . . . . . . 2-9
Delayed Locking . . . . . . . . . . . . . . 2-9
Automatic Door Locks . . . . . . . . . 2-9
Lockout Protection . . . . . . . . . . . . 2-9
Safety Locks . . . . . . . . . . . . . . . . . . 2-9
Doors Tailgate . . . . . . . . . . . . . . . . . . . . . . 2-10
Vehicle Security Vehicle Security . . . . . . . . . . . . . . 2-11
Vehicle Alarm System . . . . . . . . 2-11
Immobilizer . . . . . . . . . . . . . . . . . . 2-12
Immobilizer Operation . . . . . . . 2-13 Exterior Mirrors Convex Mirrors . . . . . . . . . . . . . . 2-14
Trailer-Tow Mirrors . . . . . . . . . . . 2-14
Power Mirrors . . . . . . . . . . . . . . . . 2-14
Folding Mirrors . . . . . . . . . . . . . . . 2-16
Heated Mirrors . . . . . . . . . . . . . . . 2-17
Automatic Dimming Mirror . . . 2-17
Blind Spot Mirrors . . . . . . . . . . . 2-17
Reverse Tilt Mirrors . . . . . . . . . . 2-18
Interior Mirrors Interior Rearview Mirrors . . . . . 2-19
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . 2-19
Windows Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Power Windows . . . . . . . . . . . . . 2-19
Rear Windows . . . . . . . . . . . . . . . 2-22
Sun Visors . . . . . . . . . . . . . . . . . . . 2-22
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . 2-22 Keys and Locks Keys
{ WarningLeaving children in a vehicle with
the ignition key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the keys in the
ignition, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with the
ignition key.

Black plate (3,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-3The key is used for the ignition and
all door locks.
Programming Keys Follow these procedures to program
up to eight keys to the vehicle.
Programming with a
Recognized Key
To program a new key:
1. Insert the original, already
programmed key in the ignition
and turn the key to the ON/RUN
position.
2. Turn the key to LOCK/OFF, and
remove the key.
3. Insert the new key to be
programmed and turn it to the
ON/RUN position within
five seconds.
The security light will turn off
once the key has been
programmed.
4. Repeat Steps 1 – 3 if additional
keys are to be programmed. If a key is lost or damaged, see your
dealer to have a new key made.
Programming without a
Recognized Key
Program a new key to the vehicle
when a recognized key is not
available. Canadian regulations
require that owners see their dealer.
If there are no currently recognized
keys available, follow this procedure
to program the first key.
This procedure will take
approximately 30 minutes to
complete for the first key. The
vehicle must be off and all of the
keys you wish to program must be
with you.
1. Insert the new vehicle key into
the ignition.
2. Turn to ON/RUN. The security
light will come on.
3. Wait 10 minutes until the
security light turns off.
4. Turn the ignition to LOCK/OFF. 5. Repeat Steps 2 – 4 two more
times. After the third time, turn to
ON/RUN; the key is learned and
all previously known keys will no
longer work with the vehicle.
Remaining keys can be learned by
following the procedure in
“ Programming with a
Recognized Key. ”
The key has a bar-coded key tag
that the dealer or qualified locksmith
can use to make new keys. Store
this information in a safe place, not
in the vehicle.
See your dealer if a replacement
key or additional key is needed.
If it becomes difficult to turn a key,
inspect the key blade for debris.
Periodically clean with a brush
or pick.
With an active OnStar subscription,
an OnStar Advisor may remotely
unlock the vehicle. See OnStar
Overview on page 14-1 .

Black plate (10,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
2-10 Keys, Doors, and Windows
Crew/Double Cab Premium
Shown, Others Similar
Press
{ to activate the safety locks
on the rear doors. The indicator light
comes on when activated. The
vehicle must be on, in ACC/
ACCESSORY, or in Retained
Accessory Power (RAP). See
Retained Accessory Power (RAP)
on page 9-29 .
If the indicator light flashes, the
feature may not be working properly. Doors Tailgate
{ WarningIt is extremely dangerous to ride
on the tailgate, even when the
vehicle is operated at low speeds.
People riding on the tailgate can
easily lose their balance and fall
in response to vehicle
maneuvers. Falling from a moving
vehicle may result in serious
injuries or death. Do not allow
people to ride on the tailgate. Be
sure everyone in your vehicle is in
a seat and using a safety belt
properly.
On vehicles with a lock on the
tailgate, use the key to lock or
unlock the tailgate.
Open the tailgate by lifting up on its
handle while pulling the
tailgate down. To shut the tailgate, firmly push it
upward until it latches.
After closing the tailgate, pull it back
to be sure it latches securely.
Tailgate Removal The tailgate can be removed to
allow for different loading situations.
Assistance may be needed with the
removal to avoid damage to the
vehicle.
On vehicles with a Rear Vision
Camera, it must be disconnected
before removing the tailgate. See
Driver Assistance Systems on
page 9-55 .

Black plate (11,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-11To remove the tailgate:
1. Raise the tailgate and support it
firmly. Pull out and hold the
cable retaining clip (1). Push the
cable (3) up and off of the
bolt (2). Repeat on the
other side. 2. With the tailgate about halfway
open, lift the right edge of the
tailgate from the lower pivot.
On vehicles with the tailgate
assist feature, raise the tailgate
nearly all the way to the closed
position prior to removing the
left edge.
3. Move the tailgate to the right and
away to release the left edge.
Reverse this procedure to reinstall
the tailgate. Make sure the tailgate
is secure. Vehicle Security This vehicle has theft-deterrent
features; however, they do not make
the vehicle impossible to steal.
Vehicle Alarm System
If equipped with the anti-theft alarm
system, the indicator light, on the
instrument panel near the
windshield, indicates the status of
the system.
Off: Alarm system is disarmed.
On Solid: Vehicle is secured
during the delay to arm the system.
Fast Flash: Vehicle is unsecured.
A door or the hood is open.

Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - CRC - 6/20/14
Keys, Doors, and Windows 2-13
Immobilizer Operation
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The system is automatically
disarmed when the key is turned to
ON/RUN, ACC/ACCESSORY,
or START from the LOCK/OFF
position. The security light, in the instrument
cluster, comes on if there is a
problem with arming or disarming
the theft-deterrent system.
When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses on page 10-41 . If the engine
still does not start with the other key,
the vehicle needs service. If the
vehicle does start, the first key may
be faulty. See your dealer. It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
on page 2-1 . To program additional
transmitters, see Remote Keyless
Entry (RKE) System Operation on
page 2-4 .
Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system.