2020 GMC SIERRA DENALI stop start

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 213
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. For Key Access vehicles, turnthe ignition key to Start. When
the engine starts, let go of the
key. For Keyless Access
vehicles, the RKE transmitter
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), hold the ignition switch
in the START position 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 pushing the accelerator pedal all the way to
the floor and holding it there
while holding the key in START
or ENGINE START/STOP for
up to a maximum of
15 seconds. Wait at least
15 seconds between each try,
to allow the cranking motor to
cool down. When the engine
starts, let go of the key or
button and accelerator. If the
vehicle starts briefly but then
stops again, do the same thing.
This clears the extra gasoline
from the engine. Do not race
the engine immediately after
starting it. Operate the engine
and transmission gently until
the oil warms up and lubricates
all moving parts.
Stop/Start System
If equipped, the Stop/Start system
will shut off the engine to help
conserve fuel. It has components
designed for the increased number
of starts.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
214 Driving and Operating
{Warning
The automatic engine Stop/Start
feature causes the engine to shut
off while the vehicle is still on. Do
not exit the vehicle before shifting
to P (Park). The vehicle may
restart and move unexpectedly.
Always shift to P (Park), and then
turn the ignition off before exiting
the vehicle.
Auto Engine Stop/Start
When the brakes are applied and
the vehicle is at a complete stop,
the engine may turn off. When
stopped, the tachometer displays
AUTO STOP. See Tachometer
0 131. When the brake pedal is
released or the accelerator pedal is
pressed, the engine will restart.
To maintain vehicle performance,
other conditions may cause the
engine to automatically restart
before the brake pedal is released. Auto Stops may not occur and/or
Auto Starts may occur because:
.
The climate control settings
require the engine to be running
to cool or heat the vehicle
interior.
. The vehicle battery charge
is low.
. The vehicle battery has recently
been disconnected.
. Minimum vehicle speed has not
been reached since the last
Auto Stop.
. The accelerator pedal is
pressed.
. The engine or transmission is
not at the required operating
temperature.
. The outside temperature is not
in the required operating range.
. The vehicle is in any gear other
than D (Drive).
. Tow/Haul Mode or other driver
modes have been selected.
. The vehicle is on a steep hill or
grade. .
The driver door has been
opened or the driver seat belt
has been unbuckled.
. The hood has been opened.
. The Auto Stop has reached the
maximum allowed time.
Auto Stop Disable Switch
If equipped, the automatic engine
Stop/Start feature can be disabled
and enabled by pressing the switch
with the
hsymbol. Auto Stop is
enabled each time you start the
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 221
Automatic
Transmission
If equipped, there is an electronic
shift lever position indicator within
the instrument cluster. This display
comes on when the ignition is in
ACC/ACCESSORY, on or
service mode.
There are several different positions
for the shift lever.
SeeDriver Mode Control 0238 and
“Range Selection Mode” under
Manual Mode 0224.
P : This position locks the rear
wheels. Use P (Park) when starting
the engine because the vehicle
cannot move easily. When parked on a hill, especially
when the vehicle has a heavy load,
you might notice an increase in the
effort to shift out of P (Park). See
“Torque Lock”
underShifting Into
Park 0217.
{Warning
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle
can move suddenly. You or others
could be injured. To be sure the
vehicle will not move, even when
you are on fairly level ground,
always set the parking brake and
move the shift lever to P (Park).
See Shifting Into Park 0217 and
Driving Characteristics and
Towing Tips 0287.
{Warning
If equipped with four-wheel drive,
the vehicle will be free to roll if the
transfer case is in N (Neutral),
even when the shift lever is in
P (Park). You or someone else
could be seriously injured. Be
sure the transfer case is in a drive
gear —2
m, 4m, or 4n—or set the
parking brake before placing the
transfer case in N (Neutral). See
Four-Wheel Drive 0227.
R : Use this gear to back up.
Caution
Shifting to R (Reverse) while the
vehicle is moving forward could
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Shift to
R (Reverse) only after the vehicle
is stopped.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
222 Driving and Operating
To rock the vehicle back and forth to
get out of snow, ice, or sand without
damaging the transmission, seeIf
the Vehicle Is Stuck 0199.
N : In this position, the engine does
not connect with the wheels. To
restart the engine when the vehicle
is already moving, use
N (Neutral) only.
Also, use N (Neutral) when the
vehicle is being towed.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift
into a drive gear while the engine
is running at high speed.
Caution
Shifting out of P (Park) or
N (Neutral) with the engine
running at high speed may
damage the transmission. The
repairs would not be covered by
the vehicle warranty. Be sure the
engine is not running at high
speed when shifting the vehicle.
Caution
A transmission or engine oil hot
message may display if the
automatic transmission fluid or
engine oil is too hot. Driving
under this condition can damage
the vehicle. Stop and idle the
engine to cool the engine oil or
automatic transmission fluid.
These messages will clear when
the engine oil or transmission
fluid has cooled sufficiently. D :
This position is for normal
driving. It provides the best fuel
economy. If more power is needed
for passing, press the accelerator
pedal down.
. When going less than about
55 km/h (35 mph), push the
accelerator pedal about
halfway down.
. When going about 55 km/h
(35 mph) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts
down to the next gear and has
more power.
Use D (Drive) and Tow/Haul Mode
when towing a trailer, carrying a
heavy load, driving on steep hills,
or driving off-road. Shift the
transmission to a lower gear if the
transmission shifts too often.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “Skidding”under
Loss of Control 0190.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 227
Tow/Haul Mode
The Tow/Haul Mode adjusts the
transmission shift pattern to reduce
shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, when towing, or when
hauling heavy loads. SeeDriver
Mode Control 0238 to activate Tow/
Haul Mode.
For vehicles without Driver Mode
Control, press the Tow/Haul button
on the center stack. If equipped, the Stop/Start system
will become unavailable when Tow/
Haul Mode is active.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See
Manual Mode 0224. Tow/Haul
Mode Grade Braking assists in
maintaining desired vehicle speeds
when driving on downhill grades by
using the engine and transmission
to slow the vehicle.
See Towing Equipment 0296.
Drive Systems
Four-Wheel Drive
If equipped, four-wheel drive
engages the front axle for extra
traction.
Read the appropriate section for
transfer case operation before
using.
Caution
Do not drive on clean, dry
pavement in 4
mand 4n(if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle’s powertrain.
Driving on clean, dry pavement in
4
mor 4nmay:
. Cause a vibration to be felt in
the steering system.
. Cause tires to wear faster.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Driving and Operating 231
Shifting Into N (Neutral)
To shift into N (Neutral):1. Start the vehicle.
2. Shift the transmission to N (Neutral).
3. Shift the transfer case to 2
m.
4. Apply the parking brake and/or brake pedal.
5. Press 2
mfive times in
10 seconds until the N (Neutral)
graphic starts flashing in the
instrument cluster. When the
shift is complete, the graphic
stops flashing. If the parking
brake and/or brake pedal is not
applied within 20 seconds, the
transfer case will remain in the
original state.
6. If the transmission is not shifted into N (Neutral) or the
vehicle has not slowed to
5 km/h (3 mph) within
20 seconds, the transfer case
will remain in its original state.
This will be indicated in the
instrument cluster. Shifting Out of N (Neutral)
To shift out of N (Neutral):
1. Turn the ignition on with the engine off. See Ignition
Positions (Keyless Access)
0 208 or
Ignition Positions (Key Access)
0 210.
2. Set the parking brake. See Electric Parking Brake 0233.
3. Shift the transmission to N (Neutral).
4. Shift the transfer case to 2
m.
Transfer case shifts out of
N (Neutral) can only be made
into 2
m. When the shift to 2mis
complete, the graphic in the
instrument cluster will stop
flashing. If the transfer case
cannot complete a shift, the
graphic will return to the
previously selected setting. Single Speed Transfer Case
If equipped, the transfer case
controls are used to shift into and
out of four-wheel drive.
To shift the transfer case, press the
desired button. The graphic in the
instrument cluster will flash while a
shift is in progress. The graphic
displayed will change to indicate the
setting requested.
When the shift is complete the
graphic will stop flashing. The DIC
message turns off once the shift is
complete. If the transfer case