ECO mode GMC SIERRA 2021 Workshop Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
442 OnStar
Reactivation for Subsequent Owners
PressQand follow the prompts to speak to
an Advisor as soon as possible. The Advisor
will update vehicle records and explain
OnStar or connected service options.
How OnStar Service Works
Automatic Crash Response, Emergency
Services, Crisis Assist, Stolen Vehicle
Assistance, Remote Services, and Roadside
Assistance are available on most vehicles.
Not all OnStar services are available
everywhere or on all vehicles. For more
information, a full description of OnStar
services, system limitations, and OnStar User
Terms, Privacy Statement, and Software
Terms:
.Call 1-888-4ONSTAR (1-888-466-7827).
.See www.onstar.com (U.S.).
.See www.onstar.ca (Canada).
.Call TTY 1-877-248-2080.
.PressQto speak with an Advisor.
OnStar or connected services cannot work
unless the vehicle is in a place where OnStar
has an agreement with a wireless service
provider for service in that area. The
wireless service provider must also have
coverage, network capacity, reception, and technology compatible with OnStar or
connected services. Service involving location
information about the vehicle cannot work
unless GPS signals are available,
unobstructed, and compatible with the
OnStar hardware. OnStar or connected
services may not work if the OnStar
equipment is not properly installed or it has
not been properly maintained. If equipment
or software is added, connected,
or modified, OnStar or connected services
may not work. Other problems beyond the
control of OnStar
—such as hills, tall
buildings, tunnels, weather, electrical system
design and architecture of the vehicle,
damage to the vehicle in a crash, or wireless
phone network congestion or jamming —
may prevent service.
See Radio Frequency Statement 0436.
Services for People with Disabilities
Advisors provide services to help with
physical disabilities and medical conditions.
Press
Qto help:
.Locate a gas station with an attendant to
pump gas.
.Find a hotel, restaurant, etc., that meets
accessibility needs.
.Provide directions to the closest hospital
or pharmacy in urgent situations.
TTY Users
OnStar has the ability to communicate to
deaf, hard-of-hearing, or speech-impaired
customers while in the vehicle. The available
dealer-installed TTY system can provide
in-vehicle access to all OnStar services,
except Virtual Advisor and OnStar
Turn-by-Turn Navigation.
If equipped, TTY mode can be turned on or
off by touching Settings, then Apps, and
then Phone. When TTY mode is on, phone
calls can be made or received with OnStar
using the infotainment display.
OnStar Personal Identification
Number (PIN)
A PIN is needed to access some OnStar
services. The PIN will need to be changed
the first time when speaking with an
Advisor. To change the OnStar PIN, contact
an OnStar Advisor by pressing
Qor calling
1-888-4ONSTAR.
Warranty
OnStar equipment may be warranted as part
of the vehicle warranty.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 451
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
DoorAjar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 427
Driver
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Driver Assistance Systems . . . . . . . . . . . . . . . 265
Driver Information Center (DIC) . . . . . . 124, 125
Driver Mode Control . . . . . . . . . . . . . . . . . . . . . . 251
Driver Mode Control Light . . . . . . . . . . . . . . . . 121
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 274
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 212
Characteristics and Towing Tips . . . . . . . . 288
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Hill and Mountain Roads . . . . . . . . . . . . . . 219
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 221
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 214
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 222
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Dual Automatic Climate Control
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
E
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Electric Brake Boost . . . . . . . . . . . . . . . . . . . . . . 246
Electric Parking Brake . . . . . . . . . . . . . . . . . . . . 247
Electric Parking Brake Light . . . . . . . . . . . . . . . 117
Electrical Equipment, Add-On . . . . . . . . . . . . .318
Electrical System
Engine Compartment Fuse Block . . . . . . . 353
Fuses and Circuit Breakers . . . . . . . . . . . . . 353
Instrument Panel Fuse Block . . . . . . 357, 358
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 334
Check Light (Malfunction Indicator) . . . . . 115
Compartment Overview . . . . . . . . . . . . . . . . 325
Coolant Temperature Gauge . . . . . . . . . . . . 112
Coolant Temperature Warning Light . . . . 121
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 335
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 427 Engine (cont'd)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 332
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . 111
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . 122
Overheated Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . 340
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
Power Messages . . . . . . . . . . . . . . . . . . . . . . . . 131
Running While Parked . . . . . . . . . . . . . . . . . 238
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Engine Air Filter Life System . . . . . . . . . . . . . 333
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 296
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 438
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . 238
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 59
Exterior Cargo Lamps . . . . . . . . . . . . . . . . . . . . 144
Exterior Lamp Controls . . . . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . . . .147

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
454 Index
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
LightingEntry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Illumination Control . . . . . . . . . . . . . . . . . . . 145
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . . . . . . 114
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Brake System Warning . . . . . . . . . . . . . . . . . 117
Charging System . . . . . . . . . . . . . . . . . . . . . . . 115
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 123
Door Ajar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Mode Control . . . . . . . . . . . . . . . . . . . . 121
Electric Parking Brake . . . . . . . . . . . . . . . . . . . 117
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . 122
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Four-Wheel-Drive . . . . . . . . . . . . . . . . . . . . . . . 118
Front Fog Lamp . . . . . . . . . . . . . . . . . . . . . . . . 123
High-Beam On . . . . . . . . . . . . . . . . . . . . . . . . . 123 Lights (cont'd)
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Hill Descent Control . . . . . . . . . . . . . . . . . . . . 119
Lane Keep Assist . . . . . . . . . . . . . . . . . . . . . . . . 119
Low Fuel Warning . . . . . . . . . . . . . . . . . . . . . 122
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Service Electric Parking Brake . . . . . . . . . . . 118
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . . 119
Traction Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Limited-Slip Differential . . . . . . . . . . . . . . . . . . 254
Lock
Steering Column . . . . . . . . . . . . . . . . . . . . . . . . 32
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . 254
Locks Automatic Door . . . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Power Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Low Fuel Warning Light . . . . . . . . . . . . . . . . . . 122
Lower Anchors and Tethers for Children (LATCH System) . . . . . . . . . . . . . . . . .77
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . . . . 48 Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Maintenance Schedule . . . . . . . . . . . . . . . . . . . 409 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Transfer Case . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Malfunction Indicator Lamp . . . . . . . . . . . . . . . 115
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .241
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . . . .41
Map Data Updates . . . . . . . . . . . . . . . . . . . . . . . . 175
Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Media
Avoiding Untrusted Devices . . . . . . . . . . . . 158
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Messages Engine Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Vehicle Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Mirror Rear Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Mirrors Automatic Dimming . . . . . . . . . . . . . . . . . . . . 37
Automatic Dimming Rearview . . . . . . . . . . 38
Blind Spot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 455
Mirrors (cont'd)Convex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Folding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Manual Rearview . . . . . . . . . . . . . . . . . . . . . . . 38
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Tilt in Reverse . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Trailer Tow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Mirrors, Interior Rearview . . . . . . . . . . . . . . . . . 38
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 Driver Control . . . . . . . . . . . . . . . . . . . . . . . . . 251
Monitor System, Tire Pressure . . . . . . . . . . . 368
Multi-band Antenna . . . . . . . . . . . . . . . . . . . . . .158
N
Navigation Connected Services . . . . . . . . . . . . . . . . . . . . 445
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Using the System . . . . . . . . . . . . . . . . . . . . . . 163
Navigation Symbols . . . . . . . . . . . . . . . . . . . . . 166
New Vehicle Break-In . . . . . . . . . . . . . . . . . . . . 228
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Oil
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Engine Oil Life System . . . . . . . . . . . . . . . . . 332
Engine Oil Pressure Gauge . . . . . . . . . . . . . . 111
Pressure Light . . . . . . . . . . . . . . . . . . . . . . . . . 122
Older Children, Restraints . . . . . . . . . . . . . . . . . . 71
Online Owner Center . . . . . . . . . . . . . . . . . . . . 430
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439
OnStar Additional Information . . . . . . . . . . . 441
OnStar Emergency . . . . . . . . . . . . . . . . . . . . . . . 441
OnStar Overview . . . . . . . . . . . . . . . . . . . . . . . . . 440
OnStar Security . . . . . . . . . . . . . . . . . . . . . . . . . . 441
OnStar System . . . . . . . . . . . . . . . . . . . . . . 162, 173
Operating Mode Overheated Engine Protection . . . . . . . . . 340
Operation
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . 340
Overheating, Engine . . . . . . . . . . . . . . . . . . . . . 338
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Instrument Panel . . . . . . . . . . . . . . . . . . . . . . . . 4
P
ParkShifting Into . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Shifting Out of . . . . . . . . . . . . . . . . . . . . . . . . 237
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Parking
Brake and P (Park) MechanismCheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Over Things That Burn . . . . . . . . . . . . . . . . . 237
Parking or Backing Assistance Systems . . . . . . . . . . . . . . . . . . . . 266
Passenger Airbag Status Indicator . . . . . . . . . 114
Passenger Compartment Air Filter . . . . . . . 209
Passenger Sensing System . . . . . . . . . . . . . . . . 66
Pedestrian Ahead Indicator . . . . . . . . . . . . . . . 119
Perchlorate Materials Requirements, California . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Personalization
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Phone Apple CarPlay and Android Auto . . . . . . . 185
Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . . 180, 181
Pickup Conversion to Chassis Cab . . . . . . . . 320
Port
USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Positioning Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174