GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
196 Climate Controls
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
closest to the window.
To close the front A/C vents, move the
sliding knobs to the full down position for
vertical slats or away from you for
horizontal slats.
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 airflow.
.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 system performance.
Check with your dealer before adding
equipment to the outside of the vehicle.
.Do not attach any devices to the air vent
slats. Doing so restricts 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 Schedule0394. To find out
what type of filter to use, see Maintenance
Replacement Parts 0399.
1. Open the lower glove box door
completely.
2. Push the dampener arm to the left untilit releases the glove box.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Climate Controls 197
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
0 394.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 199
Trailer Towing
General Towing Information . . . . . . . . . . . 276
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . . . . . 276
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . 280
Towing Equipment . . . . . . . . . . . . . . . . . . . . 284
Trailer Sway Control (TSC) . . . . . . . . . . . . . 294
Trailering App . . . . . . . . . . . . . . . . . . . . . . . . . 296
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . 306
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Pickup Conversion to Chassis Cab . . . . . 308
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-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 201
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
0 323.
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 0227.
The power steering system may require
maintenance. See Power Steering Fluid
0 323. 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-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 203
Off-Road Driving
Four-wheel-drive vehicles can be used for
off-road driving. Vehicles without four-wheel
drive and vehicles not equipped with All
Terrain (AT) or On-Off Road (OOR) tires must
not be driven off-road except on a level,
solid surface. For contact information about
the original equipment tires, see the
warranty manual.
One of the best ways for successful off-road
driving is to control the speed.
{Warning
When driving off-road, bouncing and
quick changes in direction can easily
throw you out of position. This could
cause you to lose control and crash. You
and your passengers should always wear
seat belts.
Before Driving Off-Road
.Have all necessary maintenance and
service work completed.
.Fuel the vehicle, fill fluid levels, and check
inflation pressure in all tires, including the
spare, if equipped.
.Read all the information about
four-wheel-drive vehicles in this manual.
.Remove any underbody air deflector,
if equipped. Re-attach the air deflector
after off-road driving.
.Know the local laws that apply to off-road
driving.
To gain more ground clearance if needed, it
may be necessary to remove the front fascia
lower air dam, if equipped. However, driving
without the air dam reduces fuel economy.
Caution
Operating the vehicle for extended
periods without the front fascia lower air
dam installed can cause improper airflow
to the engine. Reattach the front fascia
air dam after off-road driving.
Loading the Vehicle for Off-Road Driving
{Warning
.Unsecured cargo on the load floor can
be tossed about when driving over
rough terrain. You or your passengers
can be struck by flying objects. Secure
the cargo properly. (Continued)
Warning (Continued)
.Keep cargo in the cargo area as far
forward and as low as possible. The
heaviest things should be on the floor,
forward of the rear axle.
.Heavy loads on the roof raise the
vehicle's center of gravity, making it
more likely to roll over. You can be
seriously or fatally injured if the
vehicle rolls over. Put heavy loads
inside the cargo area, not on the roof.
For more information about loading the
vehicle, see Vehicle Load Limits 0210 and
Tires 0345.
Environmental Concerns
.Always use established trails, roads, and
areas that have been set aside for public
off-road recreational driving and obey all
posted regulations.
.Do not damage shrubs, flowers, trees,
or grasses or disturb wildlife.
.Do not park over things that burn. See
Parking over Things That Burn 0222.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
206 Driving and Operating
{Warning
Driving on frozen lakes, ponds, or rivers
can be dangerous. Ice conditions vary
greatly and the vehicle could fall through
the ice; you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only
shallow water, it can still wash away the
ground from under your tires. Traction
could be lost, and the vehicle could roll
over. Do not drive through rushing water.
Caution
Do not drive through standing water if it
is deep enough to cover the wheel hubs,
axles, or exhaust pipe. Deep water can
damage the axle and other vehicle parts.If the standing water is not too deep, drive
through it slowly. At faster speeds, water
can get into the engine and cause it to stall.
Stalling can occur if the exhaust pipe is
under water. Do not turn off the ignition
when driving through water. If the exhaust
pipe is under water, the engine will not
start. When going through water, the brakes
get wet and it may take longer to stop. See
“Driving on Wet Roads”
later in this section.
After Off-Road Driving
Remove any brush or debris that has
collected on the underbody or chassis,
or under the hood. These accumulations can
be a fire hazard. Reinstall underbody air
deflector and air dam if removed.
After operation in mud or sand, have the
brake linings cleaned and checked. These
substances can cause glazing and uneven
braking. Check the body structure, driveline,
steering, suspension, wheels, tires, and
exhaust system for damage and check the
fuel lines and cooling system for any
leakage.
More frequent maintenance service is
required. See theMaintenance Schedule
0 394.
Driving on Wet Roads
Rain and wet roads can reduce vehicle
traction and affect your ability to stop and
accelerate. Always drive slower in these
types of driving conditions and avoid driving
through large puddles and deep-standing or
flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick stop
and could cause pulling to one side. You
could lose control of the vehicle.
After driving through a large puddle of
water or a car/vehicle wash, lightly apply
the brake pedal until the brakes work
normally.
Flowing or rushing water creates strong
forces. Driving through flowing water
could cause the vehicle to be carried
away. If this happens, you and other
vehicle occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive through
flowing water.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
280 Driving and Operating
5. Gradually release the brake pedal toallow the chocks to absorb the load of
the trailer.
6. Reapply the brake pedal. Then, apply the parking brake and shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer out of the water: 1. Press and hold the brake pedal.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the sloped part of the boat
ramp, the vehicle can be shifted from
four-wheel-drive high. Shift into the drive
mode that is appropriate for the road
conditions.Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0394. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically to see that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0321.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, and
durability. Successful, safe trailering takes
correct equipment, and it has to be used
properly.
The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Driving and Operating 297
If equipped this feature allows profiles for
connected trailers to be created to view
status, to store and track trailer usage
information, and to set up towing assist
features.
The Trailering App welcome page appears
when the Trailering App is opened for the
first time from the infotainment home
screen.
When a trailer is electrically connected and
a trailer profile has not been created, there
will be an option to create a profile, use a
guest profile, or select Accessory/No trailer.
When a trailer is electrically connected and
after a Trailer Profile has been created, the
trailer detection pop-up appears with a list
of all of the custom Trailer Profiles made on
the vehicle. To load an existing Trailer
Profile, select one of the Trailer Profiles
listed, or load the Guest Trailer Profile by
selecting GUEST TRAILER. Touching
Accessory/No trailer will select Accessory/No
trailer as the active Trailer Profile and will
dismiss the pop- up. Shifting the vehicle
from P (Park) will select Guest Trailer as the
active Trailer Profile and will dismiss the
pop-up.Create a Trailer Profile
Touch Add Trailer on the trailer detection
pop-up or touch + Add Trailer in the
Trailering App.
Follow the on-screen instructions to set up
profile.
After a profile is created, set up for
additional features may become available,
such as Tow/Haul Mode reminder, Trailer
Tire Pressure Monitoring System (TTPMS),
maintenance reminders, or towing assist.
Import a Trailer Profile
Touch Import on the trailer detection pop-up
or touch Import in the Trailering App.
Follow the on-screen instructions to import a
profile.
After a profile is imported, it can be selected
from the trailer list. The Tow/Haul Mode
reminder, Brake Gain Setting, and Trailer
Tire Pressure sensor learning, if equipped, do
not import.
Trailer Feature Setup
Tow/Haul Mode Reminder
To turn the Tow/Haul Mode Reminder
setting on, touch Yes. To turn it off,
touch No.Trailer Tire Pressure Setup
If the Trailer TTPMS is detected, touch the
Tire Pressure Monitoring icon to set up tire
pressure monitoring.
The trailer tire pressure sensors can transmit
up to 7 m (23 feet) from the hitch receiver of
the vehicle.
A trailer must be electrically connected to
the vehicle before starting the
sensor-to-vehicle learn process.
After selecting Start from the Learn Sensors
screen, use the Tool Method or the Manual
Method (described below) to learn each tire
sensor, during which the current tire number
will be highlighted.
Each sensor has a maximum of two minutes
to learn. After a sensor is learned, a
checkmark appears next to the tire, the
vehicle horn sounds, the vehicle brake lamps
flash, and all working trailer lamps flash.
It then moves to the next sensor.
Touch Stop to cancel the process.
The recommended tire pressure must be
entered for the trailer tires. This allows the
vehicle to alert when the tire pressure is
high or low.