
Black plate (36,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-36 Vehicle Care
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, seeReplacement Bulbs on
page 10-40.
For any bulb‐changing procedure
not listed in this section, contact
your dealer.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps
Driver Side
1. Front Turn Signal/
Sidemarker/Parking Lamp
2. High/Low-Beam Headlamp
See your dealer for passenger side
replacement.
Headlamp
1. Open the hood.

Black plate (40,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-40 Vehicle Care
Replacement Bulbs
Exterior Lamp BulbNumber
Back-Up Lamp 921 (W16W)
Back-Up Lamp* 1156
Cargo Lamp 921 (W16W)
Center
High-Mounted
Stoplamp
(CHMSL) 921LL
Fog Lamp PS24W
Front Turn Signal
Lamp and
Parking Lamp 7443 LL
High/Low-Beam
Headlamp HIR–2
(9012 LL)
Rear
Sidemarker Lamp 194Exterior Lamp Bulb
Number
Stoplamp/Taillamp/
Turn Signal Lamp 7444 LL
Stoplamp/Turn
Signal Lamp/
Taillamp* 1157
* Chassis Cab Models
For replacement bulbs not listed
here, contact your dealer.
Electrical System
Electrical System
Overload
The vehicle has fuses to protect
against an electrical system
overload. Fuses also protect power
devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, there
are some spare fuses and a fuse
puller in the Instrument Panel Fuse
Block. The same amperage fuse
can also be borrowed. Choose
some feature of the vehicle that is
not needed to use and replace it as
soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-6 INDEX
H
Halogen Bulbs . . . . . . . . . . . . . . . . 10-36
Hazard Warning Flashers . . . . . . . 6-4
Head Restraints . . . . . . . . . . . . . . . . 3-2
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . 10-36
Automatic . . . . . . . . . . . . . . . . . . . . . . 6-3
Bulb Replacement . . . . . . . . . . 10-36
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . . 6-3
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-36
High-Beam On Light . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lamps On Reminder . . . . . . . . . 5-26
Heated Steering Wheel . . . . . . . . . . . . . . . . 5-3
Heated and Cooled Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
Heated Mirrors . . . . . . . . . . . . . . . . . 2-17
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 9-28
High-Beam On Light . . . . . . . . . . . 5-26 High-Speed Operation . . . . . . . . 10-60
Hill and Mountain Roads . . . . . . . 9-11
Hill Descent Control (HDC) . . . . 9-51
Hill Descent Control Light . . . . . . 5-22
Hill Start Assist (HSA) . . . . . . . . . 9-48
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
How to Wear Safety Belts
Properly . . . . . . . . . . . . . . . . . . . . . . 3-11
I
Idle SystemFast . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
Ignition Positions . . . . . . . . . . . . . . 9-24
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 10-34
Immobilizer . . . . . . . . . . . . . . . . . . . . 2-12
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . 5-23
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . 3-32
Infotainment . . . . . . . . . . . . . . . . . . . . 7-1
Infotainment System . . . . . . . . . . 13-15
Instrument Cluster . . . . . . . . . . . . . . 5-9
Instrument Panel Storage Area . . . . . . . . . . . . . . . . . . 4-1 Interior Rearview Mirrors . . . . . . . 2-19
Introduction . . . . . . . . . . . . . . . . . . . . . . . iii
J
Jump Starting . . . . . . . . . . . . . . . . . 10-87
K
Key and Lock Messages . . . . . . . 5-35
Keyless Entry
Remote (RKE) System . . . . . . . . 2-4
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
L
Labeling, Tire Sidewall . . . . . . . . 10-52
Lamps
Auxiliary RoofMounted Lamp . . . . . . . . . . . . . . . 6-5
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Daytime Running (DRL) . . . . . . . 6-3
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Exterior Controls . . . . . . . . . . . . . . . 6-1
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . . 6-2
Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Malfunction Indicator . . . . . . . . . 5-18

Black plate (7,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-7
Lamps (cont'd)Messages . . . . . . . . . . . . . . . . . . . . 5-35
On Reminder . . . . . . . . . . . . . . . . . 5-26
Reading . . . . . . . . . . . . . . . . . . . . . . . 6-7
Lane Departure Warning (LDW) . . . . . . . . . . . . . . . 9-61
Lane Departure Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
Lap-Shoulder Belt . . . . . . . . . . . . . 3-12
LATCH System
Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . 3-45
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . 3-38
LED Lighting . . . . . . . . . . . . . . . . . . 10-36
Light Hill Decent Control . . . . . . . . . . . 5-22
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Illumination Control . . . . . . . . . . . . 6-6
LED . . . . . . . . . . . . . . . . . . . . . . . . 10-36
Lights
Airbag Readiness . . . . . . . . . . . . . 5-16
Antilock Brake System(ABS) Warning . . . . . . . . . . . . . . 5-21
Brake System Warning . . . . . . . 5-21 Lights (cont'd)
Charging System . . . . . . . . . . . . . 5-18
Cruise Control . . . . . . . . . . . . . . . . 5-27
Door Ajar . . . . . . . . . . . . . . . . . . . . . 5-27
Engine Coolant
Temperature Warning . . . . . . . 5-24
Engine Oil Pressure . . . . . . . . . . 5-25
Flash-to-Pass . . . . . . . . . . . . . . . . . . 6-2
Four-Wheel-Drive . . . . . . . . . . . . . 5-22
Front Fog Lamp . . . . . . . . . . . . . . 5-26
High-Beam On . . . . . . . . . . . . . . . . 5-26
High/Low Beam Changer . . . . . . 6-2
Lane Departure Warning . . . . . . 5-22
Low Fuel Warning . . . . . . . . . . . . 5-25
Safety Belt Reminders . . . . . . . . 5-15
Security . . . . . . . . . . . . . . . . . . . . . . 5-26
StabiliTrak
®OFF . . . . . . . . . . . . . 5-23
Tire Pressure . . . . . . . . . . . . . . . . . 5-25
Tow/Haul Mode . . . . . . . . . . . . . . . 5-22
Traction Control System
(TCS)/StabiliTrak
®. . . . . . . . . . 5-24
Traction Off . . . . . . . . . . . . . . . . . . . 5-23
Locking Rear Axle . . . . . . . . . . . . . 9-52
Locks
Automatic Door . . . . . . . . . . . . . . . . 2-9
Delayed Locking . . . . . . . . . . . . . . . 2-9
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8 Locks (cont'd)
Lockout Protection . . . . . . . . . . . . . 2-9
Power Door . . . . . . . . . . . . . . . . . . . . 2-9
Safety . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Loss of Control . . . . . . . . . . . . . . . . . 9-5
Low Fuel Warning Light . . . . . . . . 5-25
Low-Profile Tires . . . . . . . . . . . . . . 10-51
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . 3-38
Lumbar Adjustment . . . . . . . . . . . . . 3-3 Front Seats . . . . . . . . . . . . . . . . . . . . 3-3
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . .11-16
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . 11-9
Maintenance Schedule . . . . . . . . 11-3 Recommended Fluids
and Lubricants . . . . . . . . . . . . .11-12
Transfer Case . . . . . . . . . . . . . . . . 9-40
Malfunction Indicator Lamp . . . . 5-18
Manual Mode . . . . . . . . . . . . . . . . . . 9-36
Memory Features . . . . . . . . . . . . . . . 1-8
Memory Seats . . . . . . . . . . . . . . . . . . 3-5