2020 GMC SIERRA Brakes

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 141
Electric Parking Brake
Light
MetricEnglish
This light comes on when the
parking brake is applied. If the light
continues flashing after the parking
brake is released, or while driving,
there is a problem with the Electric
Parking Brake system. A message
may also display in the Driver
Information Center (DIC).
If the light does not come on,
or remains flashing, see your dealer.
Service Electric Parking
Brake Light
This light should come on briefly
when starting the vehicle. If it does
not come on, have it fixed so it will
be ready to warn if there is a
problem.
If this light stays on, take the vehicle
to your dealer as soon as possible.
See the information for the Electric
Parking Brake under Electric
Parking Brake 0233. A message
may also display in the Driver
Information Center (DIC).
Antilock Brake System
(ABS) Warning Light
This warning light should come on
briefly when the vehicle is turned
on. If the light does not come on,
have it fixed so it will be ready to
warn if there is a problem.
If the light comes on while driving,
safely stop as soon as it is possible
and turn off the vehicle. Then turn
on the vehicle again to reset the
system.
If the ABS warning light stays on,
or comes on again while driving, the
vehicle needs service. A chime may
also sound when the light stays on.
If the ABS warning light is the only
light on, the vehicle has regular
brakes, but ABS is not functioning.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
142 Instruments and Controls
If both the ABS warning light and
the brake system warning light are
on, ABS is not functioning and there
is a problem with the regular brakes.
See your dealer for service.
SeeBrake System Warning Light
0 140.
Four-Wheel-Drive Light
Auto Mode Shown, Other Modes
Similar
If equipped, the four-wheel-drive
light displays what mode the vehicle
is in. The light will show each mode:
2WD, 4HI, AUTO (all transfer
cases); 4LOW and N (two-speed
transfer case only).
The light will flash when a shift is in
progress. Once the shift is complete
the light will be steady. If the light turns amber, there may
be a malfunction with the
four-wheel-drive system. See your
dealer.
See
Four-Wheel Drive 0227.
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
See Tow/Haul Mode 0226.
Hill Descent Control Light
If equipped, the Hill Descent Control
light comes on when the system is
ready for use. When the light
flashes, the system is active.
See Hill Descent Control (HDC)
0 237.
Lane Departure Warning
(LDW) Light (2500/3500
Series)
If equipped, this light comes on
briefly while starting the vehicle. If it
does not come on, have the vehicle
serviced.
This light is green if LDW is on and
ready to operate.
This light changes to amber and
flashes to indicate that the lane
marking has been crossed without
using a turn signal in that direction.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
152 Instruments and Controls
Brake Pad Life :This displays an
estimate of the remaining life of the
front and rear brake pads.
Messages will display based on
brake pad wear and the state of the
system. Reset the Brake Pad Life
display after replacing the brake
pads. See Brake Pad Life System
0 356.
Fuel Economy : Displays average
fuel economy, the best fuel
economy over the selected
distance, and a bar graph showing
instantaneous fuel economy.
Press the thumbwheel to change
the selected distance. Press and
hold the thumbwheel while this
display is active to reset the best
fuel economy and average fuel
economy. This display can also be
reset by selecting reset in the menu.
Engine Hours (Hourmeter) :
Shows the total number of hours the
engine has run. This display also
shows the engine idle hours.
Transmission Fluid
Temperature : Shows the
temperature of the automatic transmission fluid in either degrees
Celsius (°C) or degrees
Fahrenheit (°F).
Trailer Brake :
On vehicles with the
Integrated Trailer Brake Control
(ITBC) system, the trailer brake
display appears in the DIC.
TRAILER GAIN shows the trailer
gain setting. This setting can be
adjusted from 0.0 to 10.0 with either
a trailer connected or disconnected.
TRAILER OUTPUT shows the
power output to the trailer any time
a trailer with electric brakes is
connected. Output is displayed as a
bar graph. Dotted lines may appear
in the OUTPUT display if a trailer is
not connected.
Off Road : Displays vehicle pitch
and roll information, road wheel
angle, and four-wheel drive (4WD)
status.
Follow Distance : If equipped, the
current follow time to the vehicle
ahead is displayed as a time value
on this page. Driver Assistance :
If equipped,
shows information for Lane Keep
Assist (LKA) and Forward Collision
Alert (FCA).
Info Page Options : Scroll to
choose which info pages appear on
the DIC. Press the thumbwheel to
select or deselect.
Blank Page : Shows no
information.
Head-Up Display (HUD)
{Warning
If the HUD image is too bright or
too high in your field of view, it
may take you more time to see
things you need to see when it is
dark outside. Be sure to keep the
HUD image dim and placed low in
your field of view.
If equipped with HUD, some
information about the operation of
the vehicle is projected onto the
windshield. The image is projected
through the HUD lens on top of the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
156 Instruments and Controls
Vehicle Messages
Messages displayed on the Driver
Information Center (DIC) indicate
the status of the vehicle or some
action that may be needed to
correct a condition. Multiple
messages may appear one after
another.
The messages that do not require
immediate action can be
acknowledged and cleared by
pressing the thumbwheel. The
messages that require immediate
action cannot be cleared until that
action is performed.
All messages should be taken
seriously; clearing the message
does not correct the problem.
If a SERVICE message appears,
see your dealer.
Follow the instructions given in the
messages. The system displays
messages regarding the following
topics:
.Service Messages
. Fluid Levels .
Vehicle Security
. Brakes
. Steering
. Ride Control Systems
. Driver Assistance Systems
. Cruise Control
. Lighting and Bulb Replacement
. Wiper/Washer Systems
. Doors and Windows
. Seat Belts
. Airbag Systems
. Engine and Transmission
. Tire Pressure
. Battery
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays when the
vehicle's propulsion power is
reduced. A reduction in propulsion
power can affect the vehicle's ability
to accelerate. If this message is on,
but there is no observed reduction in performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
while this message is on, but
maximum acceleration and speed
may be reduced. Anytime this
message stays on, or displays
repeatedly, the vehicle should be
taken to your dealer for service as
soon as possible.
Under certain operating conditions,
propulsion will be disabled. Try
restarting after the vehicle has been
off for 30 seconds.
Vehicle Speed Messages
SPEED LIMITED TO XXX KM/
H (MPH)
This message shows that the
vehicle speed has been limited to
the speed displayed. The limited
speed is a protection for various
propulsion and vehicle systems,
such as lubrication, thermal, brakes,
suspension, Teen Driver if
equipped, or tires.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 185
Driving and
Operating
Driving Information
Driving for Better FuelEconomy . . . . . . . . . . . . . . . . . . . . 186
Distracted Driving . . . . . . . . . . . . 187
Defensive Driving . . . . . . . . . . . . . 187
Drunk Driving . . . . . . . . . . . . . . . . . 188
Control of a Vehicle . . . . . . . . . . . 188
Braking . . . . . . . . . . . . . . . . . . . . . . . 188
Steering . . . . . . . . . . . . . . . . . . . . . . 188
Off-Road Recovery . . . . . . . . . . . 190
Loss of Control . . . . . . . . . . . . . . . 190
Off-Road Driving . . . . . . . . . . . . . 191
Driving on Wet Roads . . . . . . . . 196
Hill and Mountain Roads . . . . . 197
Winter Driving . . . . . . . . . . . . . . . . 197
If the Vehicle Is Stuck . . . . . . . . 199
Vehicle Load Limits . . . . . . . . . . . 200
Truck-Camper Loading Information . . . . . . . . . . . . . . . . . . 206
Starting and Operating
New Vehicle Break-In . . . . . . . . . 208
Ignition Positions (KeylessAccess) . . . . . . . . . . . . . . . . . . . . . 208 Ignition Positions (Key
Access) . . . . . . . . . . . . . . . . . . . . . 210
Starting the Engine . . . . . . . . . . . 212
Stop/Start System . . . . . . . . . . . . 213
Engine Heater . . . . . . . . . . . . . . . . 215
Retained Accessory Power (RAP) . . . . . . . . . . . . . . . . 217
Shifting Into Park . . . . . . . . . . . . . 217
Shifting out of Park . . . . . . . . . . . 218
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 219
Active Fuel Management . . . . . 219
Extended Parking . . . . . . . . . . . . 219
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 220
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . . 220
Automatic Transmission
Automatic Transmission . . . . . . 221
Manual Mode . . . . . . . . . . . . . . . . . 224
Tow/Haul Mode . . . . . . . . . . . . . . . 226
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . 227
Brakes
Electric Brake Boost . . . . . . . . . . 232
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 232
Electric Parking Brake . . . . . . . . 233 Brake Assist . . . . . . . . . . . . . . . . . . 234
Hill Start Assist (HSA) . . . . . . . . 235
Ride Control Systems
Traction Control/Electronic
Stability Control . . . . . . . . . . . . . 235
Hill Descent Control (HDC) . . . 237
Driver Mode Control . . . . . . . . . . 238
Limited-Slip Differential . . . . . . . 242
Locking Rear Axle . . . . . . . . . . . . 243
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 243
Adaptive Cruise Control (1500 Series) . . . . . . . . . . . . . . . . . . . . . . 245
Driver Assistance Systems
Driver Assistance Systems . . . 256
Assistance Systems forParking or Backing . . . . . . . . . . 257
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . 268
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . 268
Automatic Emergency Braking (AEB) . . . . . . . . . . . . . . . 270
Front Pedestrian Braking (FPB) System (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 272
Side Blind Zone Alert (SBZA) . . . . . . . . . . . . . . . . 274

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
188 Driving and Operating
.Allow enough following distance
between you and the driver in
front of you.
. Focus on the task of driving.
Drunk Driving
Death and injury associated with
drinking and driving is a global
tragedy.
{Warning
Drinking and then driving is very
dangerous. Your reflexes,
perceptions, attentiveness, and
judgment can be affected by even
a small amount of alcohol. You
can have a serious —or even
fatal —collision if you drive after
drinking.
Do not drink and drive or ride with
a driver who has been drinking.
Ride home in a cab; or if you are
with a group, designate a driver
who will not drink.
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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 191
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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 193
Warning (Continued)
cause a rollover. You could be
injured or killed. Do not drive on
steep hills.
Before driving on a hill, assess the
steepness, traction, and
obstructions. If the terrain ahead
cannot be seen, get out of the
vehicle and walk the hill before
driving further.
When driving on hills:
. Use a low gear and keep a firm
grip on the steering wheel.
. Maintain a slow speed.
. When possible, drive straight up
or down the hill.
. Slow down when approaching
the top of the hill.
. Use headlamps even during the
day to make the vehicle more
visible.
{Warning
Driving to the top of a hill at high
speed can cause a crash. There
could be a drop-off, embankment,
cliff, or even another vehicle. You
could be seriously injured or
killed. As you near the top of a
hill, slow down and stay alert.
. Never go downhill forward or
backward with either the
transmission or transfer case in
N (Neutral). The brakes could
overheat and you could lose
control.
{Warning
If the vehicle has the two-speed
automatic transfer case, shifting
the transfer case to N (Neutral)
can cause your vehicle to roll
even if the transmission is in
P (Park). This is because the
N (Neutral) position on the
(Continued)
Warning (Continued)
transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
. When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
{Warning
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
(Continued)