
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Lighting 185moving up or down. This is normal.
If there is a problem, an alert will be
displayed.
The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all the
power that is needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power, whenever
needed. It can temporarily reduce
the power demands of some
accessories. Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC message might
be displayed and it is recommended
that the driver reduce the electrical
loads as much as possible.
Battery Power Protection This feature shuts off the dome and
reading lamps, if they are left on for
more than 10 minutes after the
ignition is turned off. The cargo
lamp shuts off after 20 minutes. This
prevents the battery from
running down.
Exterior Lighting Battery
Saver The exterior lamps turn off about
10 minutes after the ignition is
turned off, if the parking lamps or
headlamps have been manually left
on. This protects against draining
the battery. To restart the 10-minute timer, turn the exterior lamp control
to the
O position and then back to
the
; or
2 position.
To keep the lamps on for more than
10 minutes, the ignition must be on
or in ACC/ACCESSORY.

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
496 Index General Information (cont'd)
Vehicle Care . . . . . . . . . . . . . . . . . . 342
Glove Box . . . . . . . . . . . . . . . . . . . . . . 124
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . . 469
H Halogen Bulbs . . . . . . . . . . . . . . . . . . 378
Hazard Warning Flashers . . . . . . . 180
Head Restraints . . . . . . . . . . . . . . . . . 58
Headlamps
Aiming . . . . . . . . . . . . . . . . . . . . . . . . 377
Automatic . . . . . . . . . . . . . . . . . . . . . 179
Bulb Replacement . . . . . . . . . . . . 378
Daytime Running
Lamps (DRL) . . . . . . . . . . . . . . . . 179
Flash-to-Pass . . . . . . . . . . . . . . . . . 179
High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . . . 378
High-Beam On Light . . . . . . . . . . 157
High/Low Beam Changer . . . . . 179
Lamps On Reminder . . . . . . . . . 157
Heated
Steering Wheel . . . . . . . . . . . . . . . 130
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Heated Mirrors . . . . . . . . . . . . . . . . . . . 50 Heater
Engine Coolant . . . . . . . . . . . . . . . 260
Heating . . . . . . . . . . . . . . .224, 226, 228
High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 380
High-Beam On Light . . . . . . . . . . . . 157
High-Speed Operation . . . . . . . . . . 399
Hill and Mountain Roads . . . . . . . . 245
Hill Descent Control (HDC) . . . . . 284
Hill Descent Control Light . . . . . . . 153
Hill Start Assist (HSA) . . . . . . . . . . 282
Home Page . . . . . . . . . . . . . . . . . . . . . 189
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
How to Wear Seat Belts
Properly . . . . . . . . . . . . . . . . . . . . . . . . 70
HVAC . . . . . . . . . . . . . . . . .224, 226, 228
I Idle System
Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Ignition Positions . . . . . . . . . . . . . . . 256
Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . . . . . 374
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 46
Indicator
Vehicle Ahead . . . . . . . . . . . . . . . . 154 Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . 94
Infotainment . . . . . . . . . . . . . . . . . . . . 186
Infotainment System . . . . . . . . . . . . 478
Instrument Cluster . . . . . . . . . . . . . . 138
Instrument Panel
Storage Area . . . . . . . . . . . . . . . . . 124
Interior Rearview Mirrors . . . . . . . . . 51
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J Jack
Auxiliary . . . . . . . . . . . . . . . . . . . . . . 203
Jump Starting - North
America . . . . . . . . . . . . . . . . . . . . . . . 426
K Keyless Entry
Remote (RKE) System . . . . . . . . . 37
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
L Labeling, Tire Sidewall . . . . . . . . . . 391
Lamps
Auxiliary Roof
Mounted Lamp . . . . . . . . . . . . . . 182
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 183
Daytime Running (DRL) . . . . . . 179
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 183

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 497Lamps (cont'd)
Exterior Controls . . . . . . . . . . . . . . 176
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . 178
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Malfunction Indicator
(Check Engine) . . . . . . . . . . . . . 150
On Reminder . . . . . . . . . . . . . . . . . 157
Reading . . . . . . . . . . . . . . . . . . . . . . 183
Lane Departure
Warning (LDW) . . . . . . . . . . . . . . . . 295
Lane Departure Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Lane Keep Assist (LKA) . . . . . . . . 297
Lane Keep Assist Light . . . . . . . . . 154
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 75
Lap-Shoulder Belt . . . . . . . . . . . . . . . 71
LATCH System
Replacing Parts after a
Crash . . . . . . . . . . . . . . . . . . . . . . . . 111
LATCH, Lower Anchors and
Tethers for Children . . . . . . . . . . . . 99
LED Lighting . . . . . . . . . . . . . . . . . . . . 378
Lighting
Entry . . . . . . . . . . . . . . . . . . . . . . . . . 184
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Illumination Control . . . . . . . . . . . 182 Lighting (cont'd)
LED . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Lights
Airbag On-Off . . . . . . . . . . . . . . . . . 147
Airbag Readiness . . . . . . . . . . . . . 147
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 152
Brake System Warning . . . . . . . 152
Charging System . . . . . . . . . . . . . 149
Check Engine (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Cruise Control . . . . . . . . . . . . . . . . 158
Door Ajar . . . . . . . . . . . . . . . . . . . . . 158
Engine Coolant
Temperature Warning . . . . . . . 155
Engine Oil Pressure . . . . . . . . . . 156
Flash-to-Pass . . . . . . . . . . . . . . . . . 179
Four-Wheel-Drive . . . . . . . . . . . . . 153
Front Fog Lamp . . . . . . . . . . . . . . 157
High-Beam On . . . . . . . . . . . . . . . . 157
High/Low Beam Changer . . . . . 179
Hill Descent Control . . . . . . . . . . 153
Lane Departure Warning . . . . . . 153
Lane Keep Assist . . . . . . . . . . . . . 154
Low Fuel Warning . . . . . . . . . . . . 156
Seat Belt Reminders . . . . . . . . . . 146
Security . . . . . . . . . . . . . . . . . . . . . . 157
StabiliTrak OFF . . . . . . . . . . . . . . . 154 Lights (cont'd)
Tire Pressure . . . . . . . . . . . . . . . . . 156
Tow/Haul Mode . . . . . . . . . . . . . . . 153
Traction Control System
(TCS)/StabiliTrak . . . . . . . . . . . . 155
Traction Off . . . . . . . . . . . . . . . . . . . 154
Locking Rear Axle . . . . . . . . . . . . . . 285
Locks
Automatic Door . . . . . . . . . . . . . . . . . 41
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Lockout Protection . . . . . . . . . . . . . . 42
Power Door . . . . . . . . . . . . . . . . . . . . . 41
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Loss of Control . . . . . . . . . . . . . . . . . 238
Low Fuel Warning Light . . . . . . . . . 156
Low-Profile Tires . . . . . . . . . . . . . . . . 390
Lower Anchors and Tethers
for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . . . 99
Lumbar Adjustment . . . . . . . . . . . . . . 60
Front Seats . . . . . . . . . . . . . . . . . . . . . 60
M Maintenance
Records . . . . . . . . . . . . . . . . . . . . . . 459
Maintenance and Care
Additional . . . . . . . . . . . . . . . . . . . . . 453
Maintenance Schedule . . . . . . . . . 448