2023 GMC SIERRA climate control

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 269
.Become familiar with, and follow all state
and local laws that apply to trailer
towing. These requirements vary from
state to state.
.State laws may require the use of
extended side view mirrors. If your
visibility is limited or restricted while
towing, install extended side view mirrors
on your vehicle, even if not required.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to prevent
damage to the engine, axle, or other
parts.
.Perform the first oil change before heavy
towing.
.Do not drive over 800 km/h (50 mph) and
do not make starts at full throttle during
the first 800 km (500 mi) of trailer
towing.
.Tow in D (Drive). Tow/Haul Mode is
recommended for heavier trailers. See
Tow/Haul Mode0234. If the transmission
downshifts too often, a lower gear may
be selected using Manual Mode. See
Manual Mode 0232.
If equipped, the following driver assistance
features should be turned off when towing
a trailer:
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver assistance
features should be turned to alert or off
when towing a trailer, unless equipped with
Super Cruise:
.Automatic Emergency Braking (AEB)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert (LCA),
the LCA detection zones that extend back
from the side of the vehicle do not move
further back when a trailer is towed. Use
caution while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic Alert
(RCTA), use caution while backing up when
towing a trailer, as the RCTA detection zones
that extend out from the back of the vehicle
do not move further back when a trailer is
towed.
{Warning
To prevent serious injury or death from
carbon monoxide (CO), when towing a
trailer: (Continued)
Warning (Continued)
.Do not drive with the liftgate, trunk/
hatch, or rear-most window open.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to a
setting that brings in only outside air.
See“Climate Control Systems” in the
Index.
For more information about carbon
monoxide, see Engine Exhaust 0229.
Towing a trailer requires experience. The
combination of the vehicle and trailer is
longer and not as responsive as the vehicle
itself. Get used to the handling and braking
of the combination by driving on a level
road surface before driving on public roads.
The trailer structure, the tires, and the
brakes must all be rated to carry the
intended cargo. Inadequate trailer
equipment can cause the combination to
operate in an unexpected or unsafe manner.
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment 0276. If the trailer has
electric brakes, start the combination

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
354 Vehicle Care
times as well on the government course
as a tire graded 100. The relative
performance of tires depends upon the
actual conditions of their use, however,
and may depart significantly from the
norm due to variations in driving habits,
service practices and differences in road
characteristics and climate.
Traction
The traction grades, from highest to
lowest, are AA, A, B, and C. Those
grades represent the tire's ability to
stop on wet pavement as measured
under controlled conditions on specified
government test surfaces of asphalt and
concrete. A tire marked C may have
poor traction performance. Warning:
The traction grade assigned to this tire
is based on straight-ahead braking
traction tests, and does not include
acceleration, cornering, hydroplaning,
or peak traction characteristics.Temperature
The temperature grades are A (the
highest), B, and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled conditions
on a specified indoor laboratory test
wheel. Sustained high temperature can
cause the material of the tire to
degenerate and reduce tire life, and
excessive temperature can lead to
sudden tire failure. The grade C
corresponds to a level of performance
which all passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B and A
represent higher levels of performance
on the laboratory test wheel than the
minimum required by law. Warning:
The temperature grade for this tire is
established for a tire that is properly
inflated and not overloaded. Excessive
speed, underinflation, or excessive
loading, either separately or in
combination, can cause heat buildup
and possible tire failure.Wheel Alignment and Tire
Balance
The tires and wheels were aligned and
balanced at the factory to provide the
longest tire life and best overall
performance. Adjustments to wheel
alignment and tire balancing are not
necessary on a regular basis. Consider an
alignment check if there is unusual tire wear
or the vehicle is significantly pulling to one
side or the other. Some slight pull to the
left or right, depending on the crown of the
road and/or other road surface variations
such as troughs or ruts, is normal. If the
vehicle is vibrating when driving on a
smooth road, the tires and wheels may
need to be rebalanced. See your dealer for
proper diagnosis.
Wheel Replacement
Replace any wheel that is bent, cracked,
or badly rusted or corroded. If wheel nuts
keep coming loose, the wheel, wheel bolts,
and wheel nuts should be replaced. If the
wheel leaks air, replace it. Some aluminum
wheels can be repaired. See your dealer if
any of these conditions exist.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
418 Index
Center ConsoleStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Charging System Light . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Check Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Child Restraints Infants and Young Children . . . . . . . . . . . . . 77
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Securing . . . . . . . . . . . . . . . . . . . . . . . . 92, 96, 99
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Child Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . .25
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Cleaning
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Climate Control Systems . . . . . . . . . . . . . . . . . 196
Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 196
Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . 197
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . . 111
Collision Damage Repair . . . . . . . . . . . . . . . . . 402 Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Connections Connected Services . . . . . . . . . . . . . . . . . . . . 413
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Traction and Electronic Stability . . . . . . . 241
Control Light Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . 205
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 151
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Coolant Engine Temperature Gauge . . . . . . . . . . . . . 117
Engine Temperature Warning Light . . . . 125
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Courtesy Transportation Program . . . . . . . . 401
Coverage Explanations . . . . . . . . . . . . . . . . . . . . 171
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Customer Assistance
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Text Telephone (TTY) Users . . . . . . . . . . . . 398
Customer Information Publications Ordering Information . . . . . 404
Customer Satisfaction Procedure . . . . . . . . . 396
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 402
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Data Collection Infotainment System . . . . . . . . . . . . . . . . . . 407
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 406
Database Coverage Explanations . . . . . . . . . . 171
Daytime Running Lamps (DRL) . . . . . . . . . . . . 141
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . 205
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 415
Disabled Vehicle Transporting . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . 204
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Index 419
DoorAjar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 24
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 395
Drive Systems Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 321
Driver Assistance Systems . . . . . . . . . . . . . . . . . . . . 246
Information Center (DIC) . . . . . . . . . . . 128, 130
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Mode Control Light . . . . . . . . . . . . . . . . . . . . 125
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 257
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 204
Characteristics and Towing Tips . . . . . . . . 268
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Distracted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Hill and Mountain Roads . . . . . . . . . . . . . . 212
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 214
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 207
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 207
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 215
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Driving (cont'd)
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Dual Automatic Climate Control System . . . . 197
E
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . . . 264
ElectricParking Brake . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Parking Brake Light . . . . . . . . . . . . . . . . . . . . 122
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . 297
System Overload . . . . . . . . . . . . . . . . . . . . . . 327
Electrical System Engine Compartment Fuse Block . . . . . . . 329
Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Instrument Panel Fuse Block . . . . . . 333, 334
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
Engine
Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 310
Air Filter Life System . . . . . . . . . . . . . . . . . . 309
Check Light (Malfunction Indicator) . . . . 120
Compartment Overview . . . . . . . . . . . . . . . . 305
Coolant Temperature Gauge . . . . . . . . . . . . 117
Coolant Temperature Warning Light . . . 125 Engine (cont'd)
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . 311
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 395
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 308
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . 116
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . 126
Overheated Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . 315
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Power Messages . . . . . . . . . . . . . . . . . . . . . . . 135
Running While Parked . . . . . . . . . . . . . . . . . 230
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 276
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 406
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Extended Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . .37
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . 229
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 64
Exterior
Cargo Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lamp Controls . . . . . . . . . . . . . . . . . . . . . . . . . 139
Lamps Off Reminder . . . . . . . . . . . . . . . . . . . . 141
Lighting Battery Saver . . . . . . . . . . . . . . . . . 147

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Index 425
RestraintsWhere to Put . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Retained Accessory Power (RAP) . . . . . . . . . 227
Reverse Tilt Mirrors . . . . . . . . . . . . . . . . . . . . . . . 40
Roads Driving, Wet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Roadside Assistance Program . . . . . . . . . . . . 399
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Rotation, Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Routing, Engine Drive Belt . . . . . . . . . . . . . . . 395
Running Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Running the Vehicle While Parked . . . . . . . 230
S
Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Safety Defects Reporting Canadian Government . . . . . . . . . . . . . . . . . 405
General Motors . . . . . . . . . . . . . . . . . . . . . . . . 405
U.S. Government . . . . . . . . . . . . . . . . . . . . . . . 404
Safety System Check . . . . . . . . . . . . . . . . . . . . . 64
Satellite Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Scheduling Appointments . . . . . . . . . . . . . . . . 401
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Extender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
How to Wear Seat Belts Properly . . . . . . . 59 Seat Belts (cont'd)
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . 61
Reminders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Replacing after a Crash . . . . . . . . . . . . . . . . . 65
Use During Pregnancy . . . . . . . . . . . . . . . . . . 64
Seats Adjustment, Front . . . . . . . . . . . . . . . . . . . . . . 50
Center Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . 49
Heated and Ventilated, Front . . . . . . . . . . . 56
Heated, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Lumbar Adjustment, Front . . . . . . . . . . . . . . 53
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Power Adjustment, Front . . . . . . . . . . . . . . . . 51
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Reclining Seatbacks . . . . . . . . . . . . . . . . . . . . . 52
Underseat Storage . . . . . . . . . . . . . . . . . . . . . 101
Securing Child Restraints . . . . . . . . . . 92, 96, 99
Security Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Vehicle Alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Accessories and Modifications . . . . . . . . . 302
Climate Control System . . . . . . . . . . . . . . . . 196
Doing Your Own Work . . . . . . . . . . . . . . . . . 303
Electric Parking Brake Light . . . . . . . . . . . . 122 Service (cont'd)
Maintenance Records . . . . . . . . . . . . . . . . . . 391
Maintenance, General Information . . . . . 384
Parts Identification . . . . . . . . . . . . . . . . . . . . . 392
Scheduling Appointments . . . . . . . . . . . . . . 401
Services Special Application . . . . . . . . . . . . . . . . . . . . . 388
Servicing System . . . . . . . . . . . . . . . . . . . . . . . . . 171
Servicing the Airbag . . . . . . . . . . . . . . . . . . . . . . .73
Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
Shift Lock Control Function Check, Automatic Transmission . . . . . . . . . . . . . . . . 322
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
Out of Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . 260
Signals, Turn and Lane-Change . . . . . . . . . . . .143
Snow Plow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Software Updates . . . . . . . . . . . . . . . . . . . . . . . . .154
Special Application Services . . . . . . . . . . . . . . 388
Specifications and Capacities . . . . . . . . . . . . . 393
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Start Assist, Hill . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Start Vehicle, Remote . . . . . . . . . . . . . . . . . . . . . .22
Starting the Engine . . . . . . . . . . . . . . . . . . . . . . 225
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Column Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Fluid, Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 315