2020 GMC SIERRA DENALI airbag off

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Instruments and Controls 137
Warning (Continued)
away. SeeAirbag Readiness
Light 0135 for more information,
including important safety
information.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
It should go out when the engine is
started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging
system. Have it checked by your
dealer. Driving while this light is on
could drain the battery. When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction Indicator
Lamp (Check Engine
Light)
This light is part of the vehicle’s
emission control on-board
diagnostic system. If this light is on
while the engine is running, a
malfunction has been detected and
the vehicle may require service. The
light should come on to show that it
is working when the ignition is on
and the engine is not running. See
Ignition Positions (Keyless Access)
0
208 or
Ignition Positions (Key Access)
0 210.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when
it comes on may prevent damage.
Caution
If the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not
run smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 209
to the Keyless Access system. See
Remote Keyless Entry (RKE)
System Operation (Key Access)
013 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 16.
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. If the vehicle is in P (Park), the
ignition will turn off, and Retained
Accessory Power (RAP) will remain
active. See
Retained Accessory
Power (RAP) 0216.
If the vehicle is not in P (Park), the
ignition will return to ACC/
ACCESSORY 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
210 Driving and Operating
5. Set the parking brake. SeeElectric Parking Brake 0233.
{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.
ACC/ACCESSORY (Amber
Indicator Light) : This mode allows
some electrical accessories to be
used when the engine is off.
With the ignition off, pressing the
ENGINE START/STOP button one
time without the brake pedal applied
will place the ignition system in
ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY 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 0212.
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 ignition 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
ignition off.
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 Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 211
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 0233. 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) 0216.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
322 Driving and Operating
If Tow/Haul Mode is off and this
setting is on for a Trailer Profile,
each time the ignition is turned on a
reminder will appear to turn on Tow/
Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this
setting is on for a Trailer Profile, the
reminder will not appear when the
Trailer Profile is active.Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction
Indicator Lamp (Check Engine
Light) 0137. A device connected
to the DLC —such as an
aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 082 and
Adding Equipment to the
Airbag-Equipped Vehicle 082.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
330 Vehicle Care
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
0 471.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 082. 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 025.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0456.
Caution
Even small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine
stop/start, turn the vehicle off
before opening the hood. If the
(Continued)
Warning (Continued)
vehicle is on, the engine will start
when the hood is opened. You or
others could be injured.
{Warning
Components under the hood can
get hot from running the engine.
To help avoid the risk of burning
unprotected skin, never touch
these components until they have
cooled, and always use a glove or
towel to avoid direct skin contact.
Clear any snow from the hood
before opening.
To open the hood: 1. Pull the hood release lever with the
isymbol. It is on the
lower left side of the instrument
panel.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
470 Customer Information
Insuring the Vehicle
Protect your investment in the GM
vehicle with comprehensive and
collision insurance coverage. There
are significant differences in the
quality of coverage afforded by
various insurance policy terms.
Many insurance policies provide
reduced protection to the GM
vehicle by limiting compensation for
damage repairs through the use of
aftermarket collision parts. Some
insurance companies will not
specify aftermarket collision parts.
When purchasing insurance, we
recommend that you ensure that the
vehicle will be repaired with GM
original equipment collision parts.
If such insurance coverage is not
available from your current
insurance carrier, consider switching
to another insurance carrier.
If the vehicle is leased, the leasing
company may require you to have
insurance that ensures repairs with
Genuine GM Original Equipment
Manufacturer (OEM) parts or
Genuine Manufacturer replacementparts. Read the lease carefully, as
you may be charged at the end of
the lease for poor quality repairs.
If a Crash Occurs
If there has been an injury, call
emergency services for help. Do not
leave the scene of a crash until all
matters have been taken care of.
Move the vehicle only if its position
puts you in danger, or you are
instructed to move it by a police
officer.
Give only the necessary information
to police and other parties involved
in the crash.
For emergency towing see
Roadside Assistance Program
0
466.
Gather the following information:
. Driver name, address, and
telephone number
. Driver license number
. Owner name, address, and
telephone number
. Vehicle license plate number .
Vehicle make, model, and
model year
. Vehicle Identification
Number (VIN)
. Insurance company and policy
number
. General description of the
damage to the other vehicle
Choose a reputable repair facility
that uses quality replacement parts.
See “Collision Parts” earlier in this
section.
If the airbag has inflated, see What
Will You See after an Airbag
Inflates? 076.
Managing the Vehicle Damage
Repair Process
In the event that the vehicle requires
damage repairs, GM recommends
that you take an active role in its
repair. If you have a pre-determined
repair facility of choice, take the
vehicle there, or have it towed there.
Specify to the facility that any
required replacement collision parts
be original equipment parts, either
new Genuine GM parts or recycled

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
Index 493
Lamps (cont'd)On Reminder . . . . . . . . . . . . . . . . . 146
Reading . . . . . . . . . . . . . . . . . . . . . . 173
Lane Change Alert (LCA) . . . . . . . 274
Lane Departure
Warning (LDW) . . . . . . . . . . . . . . . . 276
Lane Departure Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Lane Keep Assist (LKA) . . . . . . . . 278
Lane Keep Assist Light . . . . . . . . . 142
Lap-Shoulder Belt . . . . . . . . . . . . . . . 67
LATCH System
Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . 104
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . 91
LED Lighting . . . . . . . . . . . . . . . . . . . . 367
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . 173
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Illumination Control . . . . . . . . . . . 172
LED . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Task . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Lights Airbag Readiness . . . . . . . . . . . . . 135
Antilock Brake System(ABS) Warning . . . . . . . . . . . . . . 140
Brake System Warning . . . . . . . 139 Lights (cont'd)
Charging System . . . . . . . . . . . . . 137
Check Engine (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 137
Cruise Control . . . . . . . . . . . . . . . . 146
Door Ajar . . . . . . . . . . . . . . . . . . . . . 147
Driver Mode Control . . . . . . . . . . 144
Electric Parking Brake . . . . . . . . 140
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . 143
Engine Coolant Temperature Warning . . . . . . . 144
Engine Oil Pressure . . . . . . . . . . 145
Flash-to-Pass . . . . . . . . . . . . . . . . . 168
Four-Wheel-Drive . . . . . . . . . . . . . 141
Front Fog Lamp . . . . . . . . . . . . . . 146
High-Beam On . . . . . . . . . . . . . . . . 146
High/Low Beam Changer . . . . . 167
Hill Descent Control . . . . . . . . . . 141
Lane Departure Warning . . . . . . 141
Lane Keep Assist . . . . . . . . . . . . . 142
Low Fuel Warning . . . . . . . . . . . . 145
Seat Belt Reminders . . . . . . . . . . 135
Security . . . . . . . . . . . . . . . . . . . . . . 146
Service Electric Parking Brake . . . . . . . . . . . . . . . . . . . . . . . 140
Tire Pressure . . . . . . . . . . . . . . . . . 144
Tow/Haul Mode . . . . . . . . . . . . . . . 141 Lights (cont'd)
Traction Off . . . . . . . . . . . . . . . . . . . 142
Limited-Slip Differential . . . . . . . . . 242
Lock Steering Column . . . . . . . . . . . . . . . . 37
Locking Rear Axle . . . . . . . . . . . . . . 242
Locks Automatic Door . . . . . . . . . . . . . . . . . 27
Delayed Locking . . . . . . . . . . . . . . . . 27
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Lockout Protection . . . . . . . . . . . . . . 28
Power Door . . . . . . . . . . . . . . . . . . . . . 27
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Loss of Control . . . . . . . . . . . . . . . . . 190
Low Fuel Warning Light . . . . . . . . . 145
Low-Profile Tires . . . . . . . . . . . . . . . . 380
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . . . 91
Lumbar Adjustment . . . . . . . . . . . . . . 56 Front Seats . . . . . . . . . . . . . . . . . . . . . 56
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . 456
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . 449
Maintenance Schedule . . . . . . . . . 441