lock GMC SIERRA 2023 Repair Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
196 Climate Controls
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . . . . . . . . . 196
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Maintenance
Passenger Compartment Air Filter . . . . . 201
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Climate Control Systems
The heating, cooling, and ventilation in the vehicle can be controlled with this system.
1. Fan Control
2. MAX Defrost
3. Air Delivery Mode Controls
4. A/C (Air Conditioning)
5. TEMP (Temperature Control)
6. Recirculation
7. Rear Window Defogger (If Equipped) or Heated Mirrors (If Equipped)9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Turn the
knob all the way counterclockwise to turn
the fan off.
TEMP : Turn clockwise or counterclockwise
to increase or decrease the temperature
inside the vehicle.
Air Delivery Mode Controls : Press
z,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Climate Controls 199
The fan, air delivery mode, air conditioning,
driver and passenger temperatures, and Sync
settings can be controlled by touching
CLIMATE on the infotainment Home Page or
the climate button in the climate control
display application tray. A selection can then
be made on the front climate control page
displayed.
Climate Control Status Display
The climate control status display appears
briefly when the center stack climate
controls are adjusted.Automatic Operation
The system automatically controls the fan
speed, air delivery, air conditioning, and
recirculation in order to heat or cool the
vehicle to the desired temperature.
When AUTO is lit, all four functions operate
automatically. Each function can also be
manually set and the selected setting is
displayed. Functions not manually set will
continue to be automatically controlled,
even if the AUTO indicator is not lit.
For automatic operation:
1. Press AUTO.
2. Set the temperature. Allow the system time to stabilize. Adjust the temperature
as needed for best comfort.
To improve fuel efficiency and to cool the
vehicle faster, recirculation may be
automatically selected in warm weather.
The recirculation light will not come on
when automatically controlled. See@
under “Manual Operation” for more details.
Manual Operation
9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Press the
knob to turn the fan off. When off is selected, a small amount of air may still
come out of the outlets depending on
vehicle speed. If any buttons are pressed or
knobs are turned, the climate control system
will turn on and operate at the current
setting.
Press AUTO to return to automatic
operation.
Driver and Passenger Temperature Control :
The temperature can be adjusted separately
for the driver and passenger.
Turn the knob clockwise or counterclockwise
to increase or decrease the driver or
passenger temperature setting. On some
models, the driver side or passenger side
temperature display shows the temperature
setting increasing or decreasing.
SYNC :
Press to link the passenger
temperature setting to the driver setting.
The SYNC indicator light will turn on. When
the passenger setting is adjusted, the SYNC
indicator light will turn off.
Air Delivery Mode Control : Press
z,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.

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
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
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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 213
For Slippery Road Driving:
.Accelerate gently. Accelerating too quickly
causes the wheels to spin and makes the
surface under the tires slick.
.Turn on Traction Control. SeeTraction
Control/Electronic Stability Control 0241.
.The Antilock Brake System (ABS) improves
vehicle stability during hard stops, but
the brakes should be applied sooner than
when on dry pavement. See Antilock
Brake System (ABS) 0238.
.Allow greater following distance and
watch for slippery spots. Icy patches can
occur on otherwise clear roads in shaded
areas. The surface of a curve or an
overpass can remain icy when the
surrounding roads are clear. Avoid sudden
steering maneuvers and braking while
on ice.
.Turn off cruise control.
Cold Weather Mode
In very low temperatures, a cold weather
message may display on the Driver
Information Center (DIC). The engine speed,
transmission shift patterns, and cabin fan
speed may operate differently to enable the vehicle to warm up quicker. You can
manually override the cabin fan speed in
cold weather mode.
Blizzard Conditions
Stop the vehicle in a safe place and signal
for help. Stay with the vehicle unless there
is help nearby. If possible, use Roadside
Assistance. See
Roadside Assistance Program
0 399. To get help and keep everyone in
the vehicle safe:
.Turn on the hazard warning flashers.
.Tie a red cloth to an outside mirror.
{Warning
Snow can trap engine exhaust under the
vehicle. This may cause exhaust gases to
get inside. Engine exhaust contains
carbon monoxide (CO), which cannot be
seen or smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in snow:
.Clear snow from the base of the
vehicle, especially any blocking the
exhaust pipe.
(Continued)
Warning (Continued)
.Open a window about 5 cm (2 in) on
the vehicle side that is away from the
wind, to bring in fresh air.
.Fully open the air outlets on or under
the instrument panel.
.Adjust the climate control system to
circulate the air inside the vehicle and
set the fan speed to the highest
setting. See“Climate Control Systems.”
For more information about CO, see
Engine Exhaust 0229.
To save fuel, run the engine for short
periods to warm the vehicle and then shut
the engine off and partially close the
window. Moving about to keep warm also
helps.
If it takes time for help to arrive, when
running the engine, push the accelerator
pedal slightly so the engine runs faster than
the idle speed. This keeps the battery
charged to restart the vehicle and to signal
for help with the headlamps. Do this as
little as possible, to save fuel.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 221
“Certification/Tire Label”underVehicle
Load Limits 0215. If weight ratings are
exceeded, move or remove items to
bring all weights below the ratings.
See your dealer for more information
on curb weights, cargo weights, Cargo
Weight Rating, and the correct center of
gravity zone.
Starting and Operating
New Vehicle Break-In
Caution
The vehicle does not need an elaborate
break-in. But it will perform better in the
long run if you follow these guidelines:
.Do not drive at any one constant
speed, fast or slow, for the first
800 km (500 mi). Do not make
full-throttle starts. Avoid downshifting
to brake or slow the vehicle.
.Avoid making hard stops for the first
300 km (200 mi) or so. During this
time the new brake linings are not yet
broken in. Hard stops with new linings
(Continued)
Caution (Continued)
can mean premature wear and earlier
replacement. Follow this breaking-in
guideline every time you get new
brake linings.
.Do not tow a trailer during break-in.
See Trailer Towing 0272 for the trailer
towing capabilities of the vehicle and
more information.
Following break-in, engine speed and load
can be gradually increased.
On new vehicles, the various mechanical and
electrical systems experience a “break-in”
period during the first 6,400 km
(4,000 miles) of routine driving. As the
vehicle is driven, the mechanical systems
adjust to provide optimal fuel economy and
transmission shift performance.
Electrical systems will adapt and calibrate
during the break-in period. A one-time
occurrence of clicks and similar vehicle
noises is normal during this process.
Normal driving charges the vehicle’s battery
to achieve the best operation of the vehicle,
including fuel economy.
Ignition Positions (Key Access)
0. Stopping the Engine/LOCK/OFF
1. ACC/ACCESSORY
2. ON/RUN
3. START
The ignition switch has four positions.
To shift out of P (Park), the ignition must be
ON/RUN and the brake pedal must be
applied.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
222 Driving and Operating
0 (Stopping the Engine/LOCK/OFF) :This
position turns off the vehicle. It also locks
the ignition, the transmission, and the
steering column, if equipped with a locking
steering column.
To turn off the vehicle:
1. Make sure that the vehicle is stopped.
2. Shift to P (Park).
3. Continue to hold the brake pedal, then set the parking brake. See Electric
Parking Brake 0239.
4. Push the key all the way in toward the steering column, then turn the key to
LOCK/OFF. 5. Remove the key.
6. Release the brake pedal.
See your dealer if the key can be removed
in any other position.
Retained Accessory Power (RAP) will remain
active. See Retained Accessory Power (RAP)
0 227.
A warning chime will sound when the driver
door is opened and the key is in the
ignition.
If equipped with a locking steering column,
the steering can bind with the front wheels
turned off center, which may prevent key
rotation out of LOCK/OFF. If this happens,
move the steering wheel from right to left
while turning the key to ACC/ACCESSORY.
If this does not work, then the vehicle needs
service.
{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, turn off the
vehicle only in an emergency. In an emergency, if the vehicle cannot be
pulled over and must be turned off while
driving:
1. Push the key all the way in toward the steering column, then turn the key to
ACC/ACCESSORY.
2. Brake using 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.
Continue braking and steer the vehicle to
a safe location.
4. Come to a complete stop.
5. Shift to P (Park).
6. Push the key all the way in toward the steering column (1), then turn the
ignition to LOCK/OFF (2).
7. Set the parking brake. See Electric
Parking Brake 0239.
8. Remove the key.
9. Release the brake pedal.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 223
Caution
Use the correct key, make sure it is all
the way in—or pushed all the way in
toward the steering column when turning
off the vehicle —and turn it only with
your hand.
1 (ACC/ACCESSORY) : This position allows
features such as the infotainment system to
operate while the vehicle is off. It also
unlocks the steering column, if equipped
with a locking steering column. Use this
position if the vehicle must be pushed or
towed. See Retained Accessory Power (RAP)
0 227.
From ON/RUN, push the key all the way in
toward the steering column, then turn the
key to ACC/ACCESSORY.
If the key is left in ACC/ACCESSORY with the
engine off, the battery could drain and the
vehicle may not start.
A warning chime will sound when the driver
door is opened and the key is in the
ignition.
2 (ON/RUN) : This position can be used to
operate the electrical accessories and to
display some instrument cluster warning
and indicator lights. This position can also be used for service and diagnostics, and to
verify the proper operation of the
malfunction indicator lamp as may be
required for emission inspection purposes.
The switch stays in this position when the
engine is running. The transmission is also
unlocked in this position.
If the key is left in ON/RUN with the engine
off, the battery could drain and the vehicle
may not start.
3 (START) :
This is the position that starts
the engine. When the engine starts, release
the key. The ignition returns to ON/RUN for
driving.
Ignition Positions (Keyless Access)
Vehicles equipped with Keyless Access have
pushbutton starting.
The remote key must be in the vehicle for
the system to operate. If the pushbutton
start is not working, the vehicle may be
near a strong radio antenna signal causing
interference to the Keyless Access system.
See Remote Keyless Entry (RKE) System
Operation (Key Access) 012 or
Remote Keyless Entry (RKE) System
Operation (Keyless Access) 014.
To shift out of P (Park), the ignition must be
on or in Service Mode, 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.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
224 Driving and Operating
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power (RAP)
will remain active. SeeRetained Accessory
Power (RAP) 0227.
If the vehicle is not in P (Park), the ignition
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 ignition system 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 ignition off.
5. Set the parking brake. See Electric
Parking Brake 0239.
{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 ignition off, pressing the button
once without the brake pedal applied will
place the ignition system in accessory mode.
The ignition 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
ignition 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 0225.
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