service indicator GMC SIERRA 2020 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 145
Engine Coolant
Temperature Warning
Light
This light comes on briefly while
starting the vehicle.
If it does not, have the vehicle
serviced by your dealer. If the
system is working normally the
indicator light goes off.
Caution
The engine coolant temperature
warning light indicates that the
vehicle has overheated. Driving
with this light on can damage the
engine and it may not be covered
by the vehicle warranty. See
Engine Overheating0351. The engine coolant temperature
warning light comes on when the
engine has overheated.
If this happens, pull over and turn
off the engine as soon as possible.
See
Engine Overheating 0351.
Driver Mode Control Light
This light comes on when Sport
Mode is selected (1500 Series).
This light comes on when Snow/Ice
Mode is selected.
This light comes on when Terrain
Mode is selected (1500 Series).
This light comes on when Off-Road
Mode is selected.
Tire Pressure Light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Instruments and Controls 147
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle
serviced by your dealer. If the
system is working normally, the
indicator light turns off.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. SeeImmobilizer Operation
0 39.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0167.
IntelliBeam Light
This light comes on when the
IntelliBeam system, if equipped, is
enabled. See Exterior Lamp
Controls 0165.
Front Fog Lamp Light
For vehicles with fog lamps, this
light comes on when the fog lamps
are on. The light goes out when the fog
lamps are turned off. See
Fog
Lamps 0170.
Lamps On Reminder
This light comes on when the
exterior lamps are in use, except
when only the Daytime Running
Lamps (DRL) are active. See
Exterior Lamp Controls 0165.
Cruise Control Light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 209
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
015.
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) 0217. 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) with an automatic
transmission, or Neutral with a
manual transmission, and
make sure engine is off. On
vehicles with an automatic
transmission, the shift lever
must be in P (Park) to turn the
ignition off.
5. Set the parking brake. See Electric Parking Brake 0233.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
210 Driving and Operating
{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. For a
manual transmission, set the
parking brake before putting the
ignition in ACC/ACCESSORY.
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 - 4/4/19
212 Driving and Operating
5. Shift to P (Park) with anautomatic transmission, or stay
in Neutral with a manual
transmission.
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 0233.
8. Remove the key.
9. Release the brake pedal.
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) 0217.
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.
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
0 322.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 221
If the vehicle is left with the engine
running, follow the proper steps to
be sure the vehicle will not move.
SeeShifting Into Park 0217 and
Engine Exhaust 0220.
If parking on a hill and pulling a
trailer, see Driving Characteristics
and Towing Tips 0287.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.
See Driver 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 253
Curves in the Road
{Warning
On curves, ACC may not detect a
vehicle ahead in your lane. You
could be startled if the vehicle
accelerates up to the set speed,
especially when following a
vehicle exiting or entering exit
ramps. You could lose control of
the vehicle or crash. Do not use
ACC while driving on an entrance
or exit ramp. Always be ready to
use the brakes if necessary.
{Warning
On curves, ACC may respond to
a vehicle in another lane, or may
not have time to react to a vehicle
in your lane. You could crash into
a vehicle ahead of you, or lose
control of your vehicle. Give extra
attention in curves and be ready(Continued)
Warning (Continued)
to use the brakes if necessary.
Select an appropriate speed while
driving in curves.
ACC may operate differently in a
sharp curve. It may reduce the
vehicle speed if the curve is too
sharp.
When following a vehicle and
entering a curve, ACC may not
detect the vehicle ahead and
accelerate to the set speed. When
this happens, the vehicle ahead
indicator will not appear.
ACC may detect a vehicle that is
not in your lane and apply the
brakes.
ACC may occasionally provide an
alert and/or braking that is
considered unnecessary. It could
respond to vehicles in different
lanes or stationary objects when
entering or exiting a curve. This is
normal operation. The vehicle does
not need service.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
270 Driving and Operating
Tailgating Alert
The vehicle ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The Collision Alert control is on the
steering wheel. Press
[to set the
FCA timing to Far, Medium, or Near.
The first button press shows the
current setting on the DIC.
Additional button presses will
change this setting. The chosen
setting will remain until it is changed
and will affect the timing of both the
Collision Alert and the Tailgating
Alert features. The timing of both
alerts will vary based on vehicle
speed. The faster the vehicle speed,
the farther away the alert will occur.
Consider traffic and weather
conditions when selecting the alert timing. The range of selectable alert
timings may not be appropriate for
all drivers and driving conditions.
If your vehicle is equipped with
Adaptive Cruise Control (ACC),
changing the FCA timing setting
automatically changes the following
gap setting (Far, Medium, or Near).
Following Distance Indicator
The following distance to a moving
vehicle ahead in your path is
indicated in following time in
seconds on the Driver Information
Center (DIC). The minimum
following time is 0.5 seconds away.
If there is no vehicle detected
ahead, or the vehicle ahead is out of
sensor range, dashes will be
displayed.
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, this may correct
the issue:
.
Clean the outside of the
windshield in front of the
rearview mirror.
. Clean the entire front of the
vehicle.
. Clean the headlamps.
Automatic Emergency
Braking (AEB)
If the vehicle has Forward Collision
Alert (FCA), it also has AEB (1500
series only), which includes
Intelligent Brake Assist (IBA). When
the system detects a vehicle ahead
in your path that is traveling in the
same direction that you may be
about to crash into, it can provide a
boost to braking or automatically
brake the vehicle. This can help
avoid or lessen the severity of
crashes when driving in a forward
gear. Depending on the situation,
the vehicle may automatically brake

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
272 Driving and Operating
{Warning
IBA may increase vehicle braking
in situations when it may not be
necessary. You could block the
flow of traffic. If this occurs, take
your foot off the brake pedal and
then apply the brakes as needed.
AEB and IBA can be disabled. See
“Collision/Detection Systems” under
Vehicle Personalization 0157.
{Warning
Using AEB or IBA while towing a
trailer could cause you to lose
control of the vehicle and crash.
Turn the system to Alert or Off
when towing a trailer.
A system unavailable message may
display if:
. The front of the vehicle or
windshield is not clean.
. Heavy rain or snow is interfering
with object detection. .
There is a problem with the
StabiliTrak/Electronic Stability
Control (ESC) system.
The AEB system does not need
service.
Front Pedestrian Braking
(FPB) System (1500
Series)
If equipped, the FPB system may
help avoid or reduce the harm
caused by front-end crashes with
nearby pedestrians when driving in
a forward gear. FPB displays an
amber indicator,
~, when a nearby
pedestrian is detected ahead. When
approaching a detected pedestrian
too quickly, FPB provides a red
flashing alert on the windshield and
rapidly beeps or pulses the driver
seat. FPB can provide a boost to
braking or automatically brake the
vehicle. This system includes
Intelligent Brake Assist (IBA), and
the Automatic Emergency Braking
(AEB) system may also respond to
pedestrians. See Automatic
Emergency Braking (AEB) 0270. The FPB system can detect and
alert to pedestrians in a forward
gear at speeds between 8 km/h
(5 mph) and 80 km/h (50 mph).
During daytime driving, the system
detects pedestrians up to a distance
of approximately 40 m (131 ft).
During nighttime driving, system
performance is very limited.
{Warning
FPB does not provide an alert or
automatically brake the vehicle,
unless it detects a pedestrian.
FPB may not detect pedestrians,
including children:
. When the pedestrian is not
directly ahead, fully visible,
or standing upright, or when
part of a group.
. Due to poor visibility,
including nighttime
conditions, fog, rain,
or snow.
. If the FPB sensor is blocked
by dirt, snow, or ice.
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 279
Warning (Continued)
bad weather conditions or on
roads with unclear lane markings,
such as construction zones.
{Warning
Using LKA while towing a trailer
or on slippery roads could cause
loss of control of the vehicle and
a crash. Turn the system off.
How the System Works
LKA uses a camera sensor installed
on the windshield ahead of the
rearview mirror to detect lane
markings. It may provide brief
steering assist if it detects an
unintended lane departure. It may
further provide an audible alert or
the driver seat may pulse indicating
that a lane marking has been
crossed.To turn LKA on and off, press
A
on the center stack. If equipped, the
indicator light on the button comes
on when LKA is on and turns off
when LKA is disabled.
When on,
Ais white, if equipped,
indicating that the system is not
ready to assist.
Ais green if LKA
is ready to assist. LKA may assist
by gently turning the steering wheel
if the vehicle approaches a detected
lane marking.
Ais amber when
assisting. It may also provide a
Lane Departure Warning (LDW)
alert by flashing
Aamber if the
vehicle crosses a detected lane
marking. Additionally, there may be
three beeps, or the driver seat may
pulse three times, on the right or
left, depending on the lane
departure direction.
Take Steering
The LKA system does not
continuously steer the vehicle.
If LKA does not detect active driver
steering, an alert and chime may be
provided. Steer the vehicle to dismiss. LKA may become
temporarily unavailable after
repeated take steering alerts.
When the System Does Not
Seem to Work Properly
The system performance may be
affected by:
.
Close vehicles ahead.
. Sudden lighting changes, such
as when driving through tunnels.
. Banked roads.
. Roads with poor lane markings,
such as two-lane roads.
A system unavailable message may
display if the camera is blocked.
The LKA system does not need
service.
A camera blocked message may
display if the camera is blocked.
Some driver assistance systems
may have reduced performance or
not work at all. An LKA or LDW
unavailable message may display if
the systems are temporarily
unavailable. This message could be
due to a blocked camera. The LKA