
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Lighting 181
Turn and Lane-Change
Signals
An arrow on the instrument cluster
flashes in the direction of the turn or
lane change.
Move the turn signal lever all the
way up or down to signal a turn.
Raise or lower the lever for less
than one second until the arrow
starts to flash to signal a lane
change. This causes the turn
signals to automatically flash three
times. It will flash six times if Tow/
Haul Mode is active. Holding the
turn signal lever for more than
one second will cause the turn
signals to flash until the lever is
released. The lever returns to its starting
position whenever it is released.
If after signaling a turn or a lane
change the arrows flash rapidly or
do not come on, a signal bulb could
be burned out. If equipped with LED
turn signals, see your dealer.
Replace any burned out bulbs. If a
bulb is not burned out, check the
fuse. See Fuses and Circuit
Breakers 0 381 .
Turn Signal On Chime
If the turn signal is left on for more
than 1.2 km (0.75 mi), a chime
sounds at each flash of the turn
signal. The message TURN
SIGNAL ON will also appear in the
Driver Information Center (DIC). To
turn the chime and message off,
move the turn signal lever to the off
position. Fog Lamps
If equipped, the control is on the
center of the exterior lamp control,
to the left of the steering column.
The ignition must be in the ON/RUN
position for the fog lamps to
come on.
# (Fog Lamps) : Press to turn the
fog lamps on or off. A light will come
on in the instrument cluster.
When the fog lamps are turned on,
the parking lamps automatically
turn on.
When the headlamps are changed
to high beam, the fog lamps go off.
When the high-beam headlamps are
turned off, the fog lamps will come
on again.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 305tires, and mirrors. Get familiar with
the handling and braking of the rig.
If the trailer has electric brakes, start
the combination moving and then
apply the trailer brake controller by
hand to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane. Backing Up Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
CautionMaking very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance. If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Turn Signals When Towing a
Trailer The turn signal indicators on the
instrument cluster flash whenever
signaling a turn or lane change.
Properly hooked up, the trailer
lamps also flash, telling other
drivers the vehicle is turning,
changing lanes, or stopping.
When towing a trailer, the arrows on
the instrument cluster flash for turns
even if the bulbs on the trailer are
burned out.
Check occasionally to be sure the
trailer bulbs are still working.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 341
Vehicle Care General Information General Information . . . . . . . . . . 342
California Proposition
65 Warning . . . . . . . . . . . . . . . . . 343
California Perchlorate
Materials Requirements . . . . . 343
Accessories and
Modifications . . . . . . . . . . . . . . . . 343
Vehicle Checks Doing Your Own
Service Work . . . . . . . . . . . . . . . 344
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 344
Engine Compartment
Overview . . . . . . . . . . . . . . . . . . . . 345
Engine Oil . . . . . . . . . . . . . . . . . . . . 350
Engine Oil Life System . . . . . . . 353
Automatic Transmission Fluid
(6-Speed Transmission) . . . . . 354
Automatic Transmission Fluid
(8-Speed Transmission) . . . . . 357
Engine Air Cleaner/Filter . . . . . . 358
Cooling System . . . . . . . . . . . . . . 359
Engine Overheating . . . . . . . . . . 363
Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . 364
Engine Fan . . . . . . . . . . . . . . . . . . . 365 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 365
Power Steering Fluid (2500/
3500 Series) . . . . . . . . . . . . . . . . 365
Washer Fluid . . . . . . . . . . . . . . . . . 366
Brakes . . . . . . . . . . . . . . . . . . . . . . . 367
Brake Fluid . . . . . . . . . . . . . . . . . . . 368
Battery - North America . . . . . . 369
Four-Wheel Drive . . . . . . . . . . . . . 370
Front Axle . . . . . . . . . . . . . . . . . . . . 370
Rear Axle . . . . . . . . . . . . . . . . . . . . 371
Noise Control System . . . . . . . . 373
Starter Switch Check . . . . . . . . . 374
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 375
Wiper Blade Replacement . . . . 375
Windshield Replacement . . . . . 376
Gas Strut(s) . . . . . . . . . . . . . . . . . . 376
Headlamp Aiming Headlamp Aiming . . . . . . . . . . . . 377
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 378
Halogen Bulbs . . . . . . . . . . . . . . . . 378 High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 378
LED Lighting . . . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Electrical System High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . 380
Electrical System Overload . . . 380
Fuses and Circuit Breakers . . . 381
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Instrument Panel Fuse Block
(Right) . . . . . . . . . . . . . . . . . . . . . . 385
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 386
Wheels and Tires Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season Tires . . . . . . . . . . . . . . 389
Winter Tires . . . . . . . . . . . . . . . . . . 390
Low-Profile Tires . . . . . . . . . . . . . 390
All-Terrain Tires . . . . . . . . . . . . . . . 391
Tire Sidewall Labeling . . . . . . . . 391
Tire Designations . . . . . . . . . . . . . 393

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
378 Vehicle Care
Bulb Replacement For the proper type of replacement
bulbs, or any bulb changing
procedure not listed in this section,
contact your dealer.
Halogen Bulbs
{ WarningHalogen 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.
High Intensity Discharge
(HID) Lighting
{ Warning
The High Intensity Discharge
(HID) lighting system operates at
a very high voltage. If you try to
(Continued) Warning (Continued) service any of the system
components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
LED Lighting This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer. Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
1. Stoplamp/Taillamp/Turn
Signal Lamp
2. Back-Up Lamp
3. Sidemarker Lamp
To replace one of these bulbs:
1. Open the tailgate.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
492 Index Antilock Brake System
(ABS) (cont'd)
Warning Light . . . . . . . . . . . . . . . . . 152
Appearance Care
Exterior . . . . . . . . . . . . . . . . . . . . . . . 435
Interior . . . . . . . . . . . . . . . . . . . . . . . . 441
Apple CarPlay and
Android Auto . . . . . . . . . . . . . . . . . . 217
Assistance Program,
Roadside . . . . . . . . . . . . . . . . . . . . . . 469
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . . . 292
Assistance Systems for
Parking and Backing . . . . . . . . . . 289
Audio
Bluetooth . . . . . . . . . . . . . . . . . . . . . 204
Theft-Deterrent Feature . . . . . . . 187
Audio Players
CD . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Automatic
Dimming Mirrors . . . . . . . . . . . . . . . . 50
Door Locks . . . . . . . . . . . . . . . . . . . . . 41
Forward Braking . . . . . . . . . . . . . . 294
Headlamp System . . . . . . . . . . . . 179
Transmission . . . . . . . . . . . . . . . . . 265
Transmission Fluid . . . . . . 354, 357
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 268 Automatic Transmission (cont'd)
Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Auxiliary
Roof Mounted Lamp . . . . . . . . . . 182
Auxiliary Jack . . . . . . . . . . . . . . . . . . . 203
Avoiding Untrusted Media
Devices . . . . . . . . . . . . . . . . . . . . . . . 195
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 370
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 371
B Battery
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Load Management . . . . . . . . . . . . 184
Power Protection . . . . . . . . . . . . . 185
Battery - North America . . . . 369, 426
Blade Replacement, Wiper . . . . . 375
Blind Spot Mirrors . . . . . . . . . . . . . . . 50
Bluetooth
Overview . . . . . . . . . . . . . . . . 211, 213
Bluetooth Audio . . . . . . . . . . . . . . . . 204
Brake
Pedal and Adjustable
Throttle . . . . . . . . . . . . . . . . . . . . . . 256
System Warning Light . . . . . . . . 152
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Brakes (cont'd)
Antilock . . . . . . . . . . . . . . . . . . . . . . . 280
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 281
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 368
Parking . . . . . . . . . . . . . . . . . . . . . . . 281
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 236
Automatic Forward . . . . . . . . . . . 294
Break-In, New Vehicle . . . . . . . . . . 255
Bulb Replacement
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Halogen Bulbs . . . . . . . . . . . . . . . . 378
Headlamp Aiming . . . . . . . . . . . . . 377
Headlamps . . . . . . . . . . . . . . . . . . . 378
High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal,
Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Buying New Tires . . . . . . . . . . . . . . . 408
C Calibration . . . . . . . . . . . . . . . . . . . . . . 131
California
Fuel Requirements . . . . . . . . . . . 300

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
502 Index Towing (cont'd)
Trailer . . . . . . . . . . . . . . . . . . . . . . . . 307
Trailer Sway Control (TSC) . . . 334
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 430
Traction
Control System (TCS)/
StabiliTrak Light . . . . . . . . . . . . . 155
Off Light . . . . . . . . . . . . . . . . . . . . . . 154
Traction Control/Electronic
Stability Control . . . . . . . . . . . . . . . 282
Trademarks and License
Agreements . . . . . . . . . . . . . . . . . . . 218
Trailer
Sway Control (TSC) . . . . . . . . . . 334
Tow Mirrors . . . . . . . . . . . . . . . . . . . . . 48
Towing . . . . . . . . . . . . . . . . . . . . . . . . 307
Transfer Case . . . . . . . . . . . . . . . . . . 272
Transmission
Automatic . . . . . . . . . . . . . . . . . . . . . 265
Fluid, Automatic . . . . . . . . . 354, 357
Temperature Gauge . . . . . . . . . . 145
Transportation Program,
Courtesy . . . . . . . . . . . . . . . . . . . . . . 471
Trip Odometer . . . . . . . . . . . . . . . . . . 142
Truck-Camper Loading
Information . . . . . . . . . . . . . . . . . . . . 253
Turn and Lane-Change
Signals . . . . . . . . . . . . . . . . . . . . . . . . 181 Turn Signal
Bulb Replacement . . . . . . . . . . . . 378
U Uniform Tire Quality Grading . . . 410
Universal Remote System . . . . . . 172
Operation . . . . . . . . . . . . . . . . . . . . . 174
Programming . . . . . . . . . . . . . . . . . 172
Updates
Software . . . . . . . . . . . . . . . . . . . . . . 189
USB Port . . . . . . . . . . . . . . . . . . . . . . . 197
Using This Manual . . . . . . . . . . . . . . . . 2
V Vehicle
Alarm System . . . . . . . . . . . . . . . . . . 44
Canadian Owners . . . . . . . . . . . . . . . 2
Control . . . . . . . . . . . . . . . . . . . . . . . 236
Identification Number (VIN) . . . 460
Load Limits . . . . . . . . . . . . . . . . . . . 248
Messages . . . . . . . . . . . . . . . . . . . . 164
Personalization . . . . . . . . . . . . . . . 165
Remote Start . . . . . . . . . . . . . . . . . . . 39
Security . . . . . . . . . . . . . . . . . . . . . . . . 44
Speed Messages . . . . . . . . . . . . . 164
Towing . . . . . . . . . . . . . . . . . . . . . . . . 430
Vehicle Ahead Indicator . . . . . . . . 154 Vehicle Care
Tire Pressure . . . . . . . . . . . . . . . . . 397
Vehicle Data Recording and
Privacy . . . . . . . . . . . . . . . . . . . . . . . . 477
Ventilation, Air . . . . . . . . . . . . . . . . . . 231
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Voice Recognition . . . . . . . . . . . . . . 205
Voltage Devices and Wiring . . . . 380
Voltmeter Gauge . . . . . . . . . . . . . . . 145
W Warning
Brake System Light . . . . . . . . . . . 152
Caution and Danger . . . . . . . . . . . . . 3
Lane Departure (LDW) . . . . . . . 295
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . . 137
Warnings
Hazard Flashers . . . . . . . . . . . . . . 180
Washer Fluid . . . . . . . . . . . . . . . . . . . 366
Wheels
Alignment and Tire Balance . . .411
Different Size . . . . . . . . . . . . . . . . . 409
Replacement . . . . . . . . . . . . . . . . . 412
When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Where to Put the Restraint . . . . . . 98
Wi-Fi . . . . . . . . . . . . . . . . . . . . . . . . . . . 482