2023 GMC SIERRA Owners Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
200 Climate Controls
Changing the mode cancels the automatic
operation and the system goes into manual
mode. Press AUTO to return to automatic
operation.
To change the current mode, select one or
more of the following:
z:Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed.
For best results, clear all snow and ice from
the windshield before defrosting.
@: Press to turn on recirculation. An
indicator light comes on. Air is recirculated
to quickly cool the inside of the vehicle.
It can also be used to help reduce outside
air and odors that enter the vehicle.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning on
or off. An indicator light comes on to show
that the air conditioning is enabled. If the
fan is turned off, the air conditioner will not
run. The A/C light will stay on even if the
outside temperatures are below freezing.
Rear Window Defogger
1REAR : If equipped, press to turn the
rear window defogger on or off. An indicator
light on the button comes on to show that
the rear window defogger is on.
The rear window defogger only works when
the engine is running.The defogger can be
turned off by turning the vehicle off or to
accessory mode.
If equipped with heated outside mirrors,
press
fto turn them on or off. See Heated
Mirrors 039.
Caution
Using a razor blade or sharp object to
clear the inside rear window can damage
the rear window defogger. Repairs would
not be covered by the vehicle warranty.
Do not clear the inside rear window with
sharp objects.
Remote Start Climate Control Operation :
If equipped with remote start, the climate
control system may run when the vehicle is
started remotely. If equipped with heated or
ventilated seats or a heated steering wheel,
these features may come on during a
remote start. See Remote Vehicle Start 022,
Heated and Ventilated Front Seats 056, and
Heated Steering Wheel 0105.
Sensors

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Climate Controls 201
The solar sensor, on top of the instrument
panel near the windshield, monitors the
solar heat.
The climate control system uses the sensor
information to adjust the temperature, fan
speed, recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise the
automatic climate control system may not
work properly.
Afterblow Feature
If equipped, under certain conditions, the
fan may stay on or may turn on and off
several times after you turn off and lock the
vehicle. This is normal.
Air Vents
Use the sliding knobs on the center and side
air vents to change the direction of the
airflow.
Air vents blow warm air on the side
windows in cold weather. If Floor, Defog,
or Defrost modes are selected, a small
amount of air will come from the vents
close to the window.To close the front a/c vents, move the
sliding knobs to the full down position.
To close the rear a/c vents, move the sliding
knobs to the full inboard position.
Operation Tips
.Clear away any ice, snow, or leaves from
air inlets at the base of the windshield
that could block the flow of air into the
vehicle.
.Clear snow off the hood to improve
visibility and help decrease moisture
drawn into the vehicle.
.Keep the path under the front seats clear
of objects to help circulate the air inside
of the vehicle more effectively.
.Use of non-GM approved hood deflectors
can adversely affect the performance of
the system. Check with your dealer
before adding equipment to the outside
of the vehicle.
.Do not attach any devices to the air vent
slats. This will restrict airflow and may
cause damage to the air vents.
Maintenance
Passenger Compartment Air Filter
The filter reduces the dust, pollen, and other
airborne irritants from outside air that is
pulled into the vehicle.
The filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule
0385. To find out
what type of filter to use, see Maintenance
Replacement Parts 0390.
1. Open the lower glove box door
completely.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
202 Climate Controls
2. Push the dampener arm to the left untilit releases the glovebox.
3. Press the sides of the glove box doorinward and rotate the door downward to
remove.
4. Pull lever on left side of the filter doorand slide left, then remove the door.
Remove the old filter.
5. Install the new air filter.
6. Reinstall the filter door.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional assistance is
needed.
Service
All vehicles have a label underhood that
identifies the refrigerant used in the vehicle.
The refrigerant system should only be
serviced by trained and certified technicians.
The air conditioning evaporator should never
be repaired or replaced by one from a
salvage vehicle. It should only be replaced
by a new evaporator to ensure proper and
safe operation.
During service, all refrigerants should be
reclaimed with proper equipment. Venting
refrigerants directly to the atmosphere is
harmful to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite, or other
health-based concerns.
The air conditioning system requires periodic
maintenance. See Maintenance Schedule
0 385.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 203
Driving and Operating
Driving Information
Driving for Better Fuel Economy . . . . . . 204
Distracted Driving . . . . . . . . . . . . . . . . . . . . . 204
Defensive Driving . . . . . . . . . . . . . . . . . . . . . 205
Impaired Driving . . . . . . . . . . . . . . . . . . . . . . 205
Control of a Vehicle . . . . . . . . . . . . . . . . . . . 205
Braking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 207
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 207
Off-Road Driving . . . . . . . . . . . . . . . . . . . . . . 208
Driving on Wet Roads . . . . . . . . . . . . . . . . . . 211
Hill and Mountain Roads . . . . . . . . . . . . . . 212
Winter Driving . . . . . . . . . . . . . . . . . . . . . . . . . 212
If the Vehicle Is Stuck . . . . . . . . . . . . . . . . . 214
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 215
Truck-Camper Loading Information . . . . . 219
Starting and Operating
New Vehicle Break-In . . . . . . . . . . . . . . . . . . 221
Ignition Positions (Key Access) . . . . . . . . . 221
Ignition Positions (Keyless Access) . . . . . 223
Starting the Engine . . . . . . . . . . . . . . . . . . . . 225
Engine Heater . . . . . . . . . . . . . . . . . . . . . . . . . 226
Retained Accessory Power (RAP) . . . . . . . 227
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . 227
Shifting out of Park . . . . . . . . . . . . . . . . . . . 228Parking over Things That Burn . . . . . . . . 229
Extended Parking . . . . . . . . . . . . . . . . . . . . . . 229
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . . . . . . . . . . . 229
Running the Vehicle While Parked . . . . . 230
Automatic Transmission
Automatic Transmission . . . . . . . . . . . . . . . 230
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . 232
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . 234
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 234
Brakes
Antilock Brake System (ABS) . . . . . . . . . . 238
Electric Parking Brake . . . . . . . . . . . . . . . . . 239
Brake Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . 240
Ride Control Systems
Traction Control/Electronic Stability
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Hill Descent Control (HDC) . . . . . . . . . . . . . 242
Driver Mode Control . . . . . . . . . . . . . . . . . . . 243
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . 244
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 244
Driver Assistance Systems
Driver Assistance Systems . . . . . . . . . . . . . 246
Assistance Systems for Parking or Backing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Rear Vision Camera (RVC) . . . . . . . . . . . . . 248
Surround Vision System . . . . . . . . . . . . . . . 249
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Rear Cross Traffic Alert (RCTA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Assistance Systems for Driving . . . . . . . . 257
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Automatic Emergency Braking (AEB) . . . . . . . . . . . . . . . . . . . . . . . . 259
Side Blind Zone Alert (SBZA) . . . . . . . . . . 260
Lane Change Alert (LCA) . . . . . . . . . . . . . . . 261
Lane Departure Warning (LDW) . . . . . . . 262
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Recommended Fuel . . . . . . . . . . . . . . . . . . . . 263
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 264
Fuels in Foreign Countries . . . . . . . . . . . . . 264
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . 264
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . 264
Filling the Tank (Pickup Models) . . . . . . . 265
Filling the Tank (Chassis Cab and Box Delete Models) . . . . . . . . . . . . . . . . . . . . . . 266
Filling a Portable Fuel Container . . . . . . 268

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
204 Driving and Operating
Trailer Towing
General Towing Information . . . . . . . . . . 268
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . . . . . 268
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . 272
Towing Equipment . . . . . . . . . . . . . . . . . . . . 276
Trailer Sway Control (TSC) . . . . . . . . . . . . . 285
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . 287
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . 297
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Pickup Conversion to Chassis Cab . . . . . 300
Driving Information
Driving for Better Fuel Economy
Driving habits can affect fuel mileage. Here
are some driving tips to get the best fuel
economy possible:
.Set the climate controls to the desired
temperature after the engine is started,
or turn them off when not required.
.Avoid fast starts and accelerate smoothly.
.Brake gradually and avoid abrupt stops.
.Avoid idling the engine for long periods
of time.
.When road and weather conditions are
appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a single trip.
.Replace the vehicle's tires with the same
TPC Spec number molded into the tire's
sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and can
take your focus from the task of driving.
Exercise good judgment and do not let other
activities divert your attention away from
the road. Many local governments have
enacted laws regarding driver distraction.
Become familiar with the local laws in
your area.
To avoid distracted driving, keep your eyes
on the road, keep your hands on the
steering wheel, and focus your attention on
driving.
.Do not use a phone in demanding driving
situations. Use a hands-free method to
place or receive necessary phone calls.
.Watch the road. Do not read, take notes,
or look up information on phones or
other electronic devices.
.Designate a front seat passenger to
handle potential distractions.
.Become familiar with vehicle features
before driving, such as programming
favorite radio stations and adjusting
climate control and seat settings. Program
all trip information into any navigation
device prior to driving.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 205
.Wait until the vehicle is parked to
retrieve items that have fallen to the
floor.
.Stop or park the vehicle to tend to
children.
.Keep pets in an appropriate carrier or
restraint.
.Avoid stressful conversations while
driving, whether with a passenger or on a
cell phone.
{Warning
Taking your eyes off the road too long or
too often could cause a crash resulting in
injury or death. Focus your attention on
driving.
Refer to the infotainment section for more
information on using that system and the
navigation system, if equipped, including
pairing and using a cell phone.
Defensive Driving
Defensive driving means “always expect the
unexpected.” The first step in driving
defensively is to wear the seat belt. See
Seat Belts 058.
.Assume that other road users
(pedestrians, bicyclists, and other drivers)
are going to be careless and make
mistakes. Anticipate what they may do
and be ready.
.Allow enough following distance between
you and the driver in front of you.
.Focus on the task of driving.
Impaired Driving
Death and injury associated with impaired
driving is a global tragedy.
{Warning
Drinking alcohol or taking drugs and then
driving is very dangerous. Your reflexes,
perceptions, attentiveness, and judgment
can be affected by even a small amount
of alcohol or drugs. You can have a
serious —or even fatal —collision if you
drive after drinking or taking drugs.
Do not drive while under the influence of
alcohol or drugs, or ride with a driver
who has been drinking or is impaired by
drugs. Find alternate transportation
home; or if you are with a group,
designate a driver who will remain sober.
Control of a Vehicle
Braking, steering, and accelerating are
important factors in helping to control a
vehicle while driving.
Braking
Braking action involves perception time and
reaction time. Deciding to push the brake
pedal is perception time. Actually doing it is
reaction time.
Average driver reaction time is about
three-quarters of a second. In that time, a
vehicle moving at 100 km/h (60 mph) travels
20 m (66 ft), which could be a lot of
distance in an emergency.
Helpful braking tips to keep in mind include:
.Keep enough distance between you and
the vehicle in front of you.
.Avoid needless heavy braking.
.Keep pace with traffic.
If the engine ever stops or a brake fault
occurs, the brakes may lose power assist.
More effort will be required to stop the
vehicle. It may take longer to stop.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
206 Driving and Operating
Steering
Caution
To avoid damage to the steering system,
do not drive over curbs, parking barriers,
or similar objects at speeds greater than
3 km/h (1 mph). Use care when driving
over other objects such as lane dividers
and speed bumps. Damage caused by
misuse of the vehicle is not covered by
the vehicle warranty.
Hydraulic Power Steering (2500/3500
Series)
(2500/3500 Series–All Regular Cab, Double
Cab/Crew Cab with Base Interior)
The power steering system may require
maintenance. See Power Steering Fluid 0315.
If power steering assist is lost because the
engine stops or the system malfunctions,
the vehicle can be steered but may require
increased effort. See your dealer.
(2500/3500 Series –Double Cab/Crew Cab
with Uplevel Interior)
The vehicle has a power steering system
that varies the amount of effort required to
steer the vehicle. Less steering effort is
required at slower speeds. At faster speeds,
the required steering effort increases. The
system helps the steering wheel return to
center at low speeds. Pressing the Tow/Haul
mode button adjusts steering effort for
driving conditions described in Tow/Haul
Mode 0234.
The power steering system may require
maintenance. See Power Steering Fluid 0315. If power steering assist is lost because the
engine stops or the system malfunctions,
the vehicle can be steered but may require
increased effort. See your dealer.
{Warning
Do not hold the brake pedal and press
the accelerator pedal at the same time.
Damage may occur to the power steering
and power brake systems which could
lead to reduced performance, up to and
including loss of steering and brake
assist.
Caution
Do not hold the steering wheel at full
rotation for more than 15 seconds and/or
at an elevated RPM. Damage may occur
to the power steering system and there
may be loss of power steering assist.
Curve Tips
.Take curves at a reasonable speed.
.Reduce speed before entering a curve.
.Maintain a reasonable steady speed
through the curve.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 207
.Wait until the vehicle is out of the curve
before accelerating gently into the
straightaway.
Steering in Emergencies
.There are some situations when steering
around a problem may be more effective
than braking.
.Holding both sides of the steering wheel
allows you to turn 180 degrees without
removing a hand.
.Antilock Brake System (ABS) allows
steering while braking.
Off-Road Recovery
The vehicle's right wheels can drop off the
edge of a road onto the shoulder while
driving. Follow these tips:1. Ease off the accelerator and then, if there is nothing in the way, steer the
vehicle so that it straddles the edge of
the pavement.
2. Turn the steering wheel about one-eighth of a turn, until the right front
tire contacts the pavement edge.
3. Turn the steering wheel to go straight down the roadway.
Loss of Control
Skidding
There are three types of skids that
correspond to the vehicle's three control
systems:
.Braking Skid —wheels are not rolling.
.Steering or Cornering Skid —too much
speed or steering in a curve causes tires
to slip and lose cornering force.
.Acceleration Skid —too much throttle
causes the driving wheels to spin. Defensive drivers avoid most skids by taking
reasonable care suited to existing conditions,
and by not overdriving those conditions. But
skids are always possible.
If the vehicle starts to slide, follow these
suggestions:
.Ease your foot off the accelerator pedal
and steer the way you want the vehicle
to go. The vehicle may straighten out. Be
ready for a second skid if it occurs.
.Slow down and adjust your driving
according to weather conditions. Stopping
distance can be longer and vehicle control
can be affected when traction is reduced
by water, snow, ice, gravel, or other
material on the road. Learn to recognize
warning clues
—such as enough water,
ice, or packed snow on the road to make
a mirrored surface —and slow down
when you have any doubt.
.Try to avoid sudden steering, acceleration,
or braking, including reducing vehicle
speed by shifting to a lower gear. Any
sudden changes could cause the tires to
slide.
Remember: Antilock brakes help avoid only
the braking skid.