
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/13/22
Driving and Operating 217
near a strong radio antenna signal causing
interference to the Keyless Access system.
SeeRemote Key Operation 015.
To shift out of P (Park), the vehicle must be
on and the brake pedal must be applied.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the vehicle will
turn off, and Retained Accessory Power (RAP)
will remain active. See Retained Accessory
Power (RAP) 0220.
If the vehicle is not in P (Park), the vehicle
will return to accessory mode and display
the message SHIFT TO PARK in the Driver
Information Center (DIC). When the vehicle is
shifted into P (Park), the vehicle will turn off. The vehicle may have an electric steering
column lock. The lock is activated when the
ignition is turned off and driver door is
opened. A sound may be heard as the lock
actuates or releases. The steering column
lock may not release with the wheels turned
off center. If this happens, the vehicle may
not start. Move the steering wheel from left
to right while attempting to start the
vehicle. If this does not work, the vehicle
needs service.
Unless an emergency exists, do not turn the
engine off when the vehicle is moving. This
will cause a loss of power assist in the brake
and steering systems and disable the
airbags.
If the vehicle must be shut off in an
emergency:
1. If the vehicle cannot be pulled over, and must be shut off while driving, press and
hold ENGINE START/STOP button for
longer than two seconds, or press twice
in five seconds.
2. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force. 3. Shift the vehicle to N (Neutral). This can
be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
4. Come to a complete stop, shift to P (Park), and make sure engine is off.
The shift lever must be in P (Park) to
turn the vehicle off.
5. Set the parking brake. See Electric
Parking Brake 0234.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Accessory Mode (Amber Indicator Light) :
This mode allows some electrical accessories
to be used when the engine is off.
With the vehicle off, pressing the ENGINE
START/STOP button one time without the
brake pedal applied will place the vehicle in
accessory mode.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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218 Driving and Operating
The vehicle will switch from accessory mode
to off after five minutes to prevent battery
rundown.
ON/RUN/START (Green Indicator Light) :This
mode is for driving and starting. With the
vehicle off, and the brake pedal applied,
pressing ENGINE START/STOP button once
will turn the ignition on. Once engine
cranking begins, release the button. Engine
cranking will continue until the engine
starts. See Starting the Engine 0218.
Service Mode
This power mode is available for service and
diagnostics, and to verify the proper
operation of the malfunction indicator lamp
as may be required for emission inspection
purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the ENGINE START/STOP button for
more than five seconds will place the vehicle
in Service Mode. The instruments and audio
systems will operate as they do when the
vehicle is on, but the vehicle will not be able
to be driven. The engine will not start in
Service Mode. Press the ENGINE START/STOP
button again to turn the vehicle off.Starting the Engine
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Caution
If you add electrical parts or accessories,
you could change the way the engine
operates. Any resulting damage would
not be covered by the vehicle warranty.
See Add-On Electrical Equipment 0306.
Move the shift lever to P (Park) or
N (Neutral). To restart the engine when the
vehicle is already moving, use
N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could
damage the transmission. Shift to P (Park)
only when the vehicle is stopped.
Starting Procedure
1. The remote key must be in the vehicle. Press ENGINE START/STOP with the brake
pedal applied. When the engine begins
cranking, let go of the button. The driver may observe a minor, and
temporary, brake pedal kickback when
starting the vehicle. This is normal.
The idle speed will go down as the
engine gets warm. Do not race the
engine immediately after starting it.
Operate the engine and transmission
gently to allow the oil to warm up and
lubricate all moving parts.
When the low fuel warning light is on
and the FUEL LEVEL LOW message is
displayed in the Driver Information
Center (DIC), press ENGINE START/STOP
to continue engine cranking.
Caution
Cranking the engine for long periods of
time, by returning the ignition to the
START position immediately after
cranking has ended, can overheat and
damage the cranking motor, and drain
the battery. Wait at least 15 seconds
between each try, to let the cranking
motor cool down.
2. If the engine does not start after five to 10 seconds, especially in very cold
weather (below −18 °C or 0 °F), it could
be flooded with too much gasoline. Try

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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222 Driving and Operating
If the vehicle has an uncharged or low
voltage battery, try charging or jump
starting the battery. SeeJump Starting -
North America 0376.
To shift out of P (Park): 1. Apply the brake pedal.
2. Release the parking brake if it is applied. See Electric Parking Brake 0234.
3. Pull the shift lever toward you, then move it to the desired position, and
release.
If the vehicle still cannot be shifted out of
P (Park): 1. Ease the pressure on, or release the shift lever.
2. While holding the brake pedal, push the shift lever all the way into P (Park).
3. Pull the shift lever toward you, then move it to the desired position, and
release.
If equipped, the Buckle to Drive feature may
prevent shifting from P (Park). See Buckle To
Drive 058.
If there is still a problem shifting, have the
vehicle serviced soon.Parking over Things That Burn
{Warning
Things that can burn could touch hot
exhaust parts under the vehicle and
ignite. Do not park over papers, leaves,
dry grass, or other things that can burn.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running, be
sure it will not move and there is adequate
ventilation.
See Shifting Into Park 0220 and
Engine Exhaust 0222.
If the vehicle is left parked and running with
the remote key outside the vehicle, it will
continue to run for up to 15 minutes.
If the vehicle is left parked and running with
the remote key inside the vehicle, it will
continue to run for up to 30 minutes.
The vehicle could turn off sooner if it is
parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is taken
out of P (Park) while it is running. When the vehicle was produced, it came
with the auto-shutdown feature enabled.
If you are not the primary owner of your
vehicle, please note that this feature may
have been disabled by a previous owner.
The vehicle owners can have this feature
re-enabled at owner cost at any GM service
center.
Engine Exhaust
{
Warning
Engine exhaust contains carbon monoxide
(CO), which cannot be seen or smelled.
Exposure to CO can cause
unconsciousness and even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with poor
ventilation (parking garages, tunnels,
deep snow that may block underbody
airflow or tail pipes).
.The exhaust smells or sounds strange
or different.
.The exhaust system leaks due to
corrosion or damage. (Continued)

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Vehicle Care 311
Caution
When adding accessories or other
equipment after the purchase of your
vehicle, ensure you are not exceeding the
vehicle axle weight ratings or overall
weight ratings. Overloading the vehicle
may cause damage. Repairs would not be
covered by the vehicle warranty. Do not
overload the vehicle. SeeVehicle Load
Limits 0210 and
Trailer Towing 0280 for those specific
weight ratings.
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts. GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 073.
Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work. If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see
Publication Ordering
Information 0413.
This vehicle has an airbag system. Before
attempting to do your own service work,
see Servicing the Airbag-Equipped Vehicle
0 73.
If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See Remote Vehicle Start 021.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 400.
Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.

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314 Vehicle Care
1. Remote Negative (–) Location. SeeJump
Starting - North America 0376.
2. Positive (+) Terminal (Under Cover). See Jump Starting - North America 0376.
3. Battery - North America 0327.
4. Engine Air Cleaner/Filter 0318.
5. Engine Oil Dipstick. See “Checking Engine
Oil” under Engine Oil 0314.
6. Engine Cooling Fan (Out of View). See Cooling System 0319.
7. Power Steering Fluid Reservoir. See Power Steering Fluid 0323.
8. Engine Oil Fill Cap. See “When to Add
Engine Oil” underEngine Oil 0314.
9. Auxiliary Battery. Battery - North
America 0327.
10. Brake Fluid Reservoir. See Brake Fluid
0 326.
11. Engine Compartment Fuse Block 0337.
12. Coolant Surge Tank and Pressure Cap. SeeCooling System 0319.
13. Windshield Washer Fluid Reservoir. See “Adding Washer Fluid” underWasher
Fluid 0324.
If the vehicle has a diesel engine, see the
Duramax diesel supplement.Engine Oil
For diesel engine vehicles, see “Engine Oil”
in the Duramax diesel supplement.
To ensure proper engine performance and
long life, careful attention must be paid to
engine oil. Following these simple, but
important steps will help protect your
investment:
.Use engine oil approved to the proper
specification and of the proper viscosity
grade. See “Selecting the Right Engine
Oil” in this section.
.Check the engine oil level regularly and
maintain the proper oil level. See
“Checking Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the appropriate
time. SeeEngine Oil Life System 0316.
.Always dispose of engine oil properly. See
“What to Do with Used Oil” in this
section.
Checking Engine Oil
Check the engine oil level regularly, every
650 km (400 mi), especially prior to a long
trip. The engine oil dipstick handle is a loop.
See Engine Compartment Overview 0313 for
the location.
{Warning
The engine oil dipstick handle may be
hot; it could burn you. Use a towel or
glove to touch the dipstick handle.
If a low oil Driver Information Center (DIC)
message displays, check the oil level.
Follow these guidelines:
.To get an accurate reading, park the
vehicle on level ground. Check the engine
oil level after the engine has been off for
at least two hours. Checking the engine
oil level on steep grades or too soon after
engine shutoff can result in incorrect
readings. Accuracy improves when
checking a cold engine prior to starting.
Remove the dipstick and check the level.
.If unable to wait two hours, the engine
must be off for at least 15 minutes if the
engine is warm, or at least 30 minutes if
the engine is not warm. Pull out the
dipstick, wipe it with a clean paper towel
or cloth, then push it back in all the way.
Remove it again, keeping the tip down,
and check the level.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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378 Vehicle Care
Caution (Continued)
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off on both vehicles. Unplug unnecessary accessories plugged
into the accessory power outlets. Turn
off the radio and all the lamps that are
not needed. This will avoid sparks and
help save both batteries. And it could
save the radio!
5. Open the hood on the other vehicle and locate the positive (+) and negative (−)
terminal locations on that vehicle.
{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
6. Check that the jumper cables do not have loose or missing insulation. If they
do, you could get a shock. The vehicles
could be damaged too.
Before you connect the cables, here are
some basic things you should know.
Positive (+) will go to positive (+) or to a
remote positive (+) terminal if the vehicle has one. Negative (–) will go to a
heavy, unpainted metal engine part or to
a remote negative (–) terminal if the
vehicle has one.
Do not connect positive (+) to negative
(–) or you will get a short that would
damage the battery and maybe other
parts too. And do not connect the
negative (–) cable to the negative (–)
terminal on the dead battery because
this can cause sparks.
7. Connect one end of the red positive (+) cable to the discharged battery
positive (+) terminal.
8. Do not let the other end touch metal. Connect it to the good battery
positive (+) terminal. Use a remote
positive (+) terminal if the vehicle
has one.
9. Connect one end of the black negative (–) cable to the good battery negative
(–) terminal. Use a remote negative (–)
terminal if the vehicle has one.
Do not let the other end touch anything
until the next step.
10. Connect the other end of the negative (–) cable to the discharged battery
negative (–) grounding point.

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382 Vehicle Care
{Warning
To avoid death, serious injury,
or property damage, before dinghy
towing the vehicle, always disconnect and
secure the negative battery cable and
cover the negative battery post and cable
with a non-conductive material. If the
battery is left connected or the battery
cable contacts the post, the Electric
Parking Brake may activate during
towing, which could cause a crash.
8. Disconnect the negative (–) battery cable. See “Negative Battery Cable
Disconnection” inBattery - North
America 0327.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked, vehicle
damage may occur.
10. Move the steering wheel to make sure the steering column is unlocked.
11. Keep the remote key outside of the vehicle and manually lock the doors.
Access the vehicle by using the key in
the door lock. See Door Locks022. Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle:
1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Reconnect the negative (–) battery. See Battery - North America 0327.
3. Turn on the vehicle. With your foot off the brake pedal, press and hold ENGINE
START/STOP for five seconds until the
green light comes on in the button. See
Ignition Positions 0216.
4. Set the parking brake. See Electric
Parking Brake 0234.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0125.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting. 9. Shift the transmission to P (Park) and
turn off the vehicle.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets.
The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.
Dolly Towing

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Customer Information 409
In the U.S., anyone driving the vehicle is
covered. In Canada, a person driving the
vehicle without permission from the owner
is not covered.
Roadside Assistance is not a part of the New
Vehicle Limited Warranty. General Motors
North America and GMC reserve the right to
make any changes or discontinue the
Roadside Assistance program at any time
without notification.
General Motors North America and GMC
reserve the right to limit services or
payment to an owner or driver if they
decide the claims are made too often, or the
same type of claim is made many times.
Services Provided
.Emergency Fuel Delivery:Delivery of
enough fuel for the vehicle to get to the
nearest service station.
.Lock-Out Service: Service to unlock the
vehicle if you are locked out. A remote
unlock may be available if you have
OnStar. For security reasons, the driver
must present identification before this
service is given.
.Emergency Tow from a Public Road or
Highway: Tow to the nearest GMC dealer
for warranty service, or if the vehicle was
in a crash and cannot be driven.
Assistance is not given when the vehicle
is stuck in the sand, mud, or snow.
.Flat Tire Change: Service to change a flat
tire with the spare tire. The spare tire,
if equipped, must be in good condition
and properly inflated. It is the owner's
responsibility for the repair or
replacement of the tire if it is not covered
by the warranty.
.Battery Jump Start: Service to jump start
a dead battery.
.Trip Interruption Benefits and Assistance:
If your trip is interrupted due to a
warranty event, incidental expenses may
be reimbursed within the Powertrain
warranty period. Items considered are
reasonable and customary hotel, meals,
rental car, or a vehicle being delivered
back to the customer, up to 500 miles.
Services Not Included in Roadside
Assistance
.Impound towing caused by violation of
any laws
.Legal fines
.Mounting, dismounting, or changing of
snow tires, chains, or other traction
devices
Service is not provided if a vehicle is in an
area that is not accessible to the service
vehicle or is not a regularly traveled or
maintained public road, which includes ice
and winter roads. Off-road use is not
covered.
Services Specific to Canadian-Purchased
Vehicles
.Fuel Delivery: Reimbursement is up to
7 liters. Diesel fuel delivery may be
restricted. Propane and other fuels are
not provided through this service.
.Lock-Out Service: Vehicle registration is
required.