2021 CHEVROLET TAHOE change time

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
198 Infotainment System
Gracenote" logo are either registered
trademarks or trademarks of Gracenote in
the United States and/or other countries.
Gracenote Terms of Use
This application or device contains software
from Gracenote, Inc. of Emeryville, California
("Gracenote"). The software from Gracenote
(the "Gracenote Software") enables this
application to do disc or file identification
and obtain music-related information,
including name, artist, track, and title
information ("Gracenote Data") from online
servers or embedded databases (collectively,
"Gracenote Servers") and to perform other
functions. You may use Gracenote Data only
by means of the intended End-User
functions of this application or device.
This application or device may contain
content belonging to Gracenote’s providers.
If so, all of the restrictions set forth herein
with respect to Gracenote Data shall also
apply to such content and such content
providers shall be entitled to all of the
benefits and protections set forth herein
that are available to Gracenote.
You agree that you will use Gracenote Data,
the Gracenote Software, and Gracenote
Servers for your own personal
non-commercial use only. You agree not toassign, copy, transfer or transmit the
Gracenote Software or any Gracenote Data
to any third party. YOU AGREE NOT TO USE
OR EXPLOIT GRACENOTE DATA, THE
GRACENOTE SOFTWARE, OR GRACENOTE
SERVERS, EXCEPT AS EXPRESSLY PERMITTED
HEREIN.
You agree that your non-exclusive license to
use the Gracenote Data, the Gracenote
Software, and Gracenote Servers will
terminate if you violate these restrictions.
If your license terminates, you agree to
cease any and all use of the Gracenote Data,
the Gracenote Software, and Gracenote
Servers. Gracenote reserves all rights in
Gracenote Data, the Gracenote Software,
and the Gracenote Servers, including all
ownership rights. Under no circumstances
will Gracenote become liable for any
payment to you for any information that
you provide. You agree that Gracenote may
enforce its rights under this Agreement
against you directly in its own name.
The Gracenote service uses a unique
identifier to track queries for statistical
purposes. The purpose of a randomly
assigned numeric identifier is to allow the
Gracenote service to count queries without
knowing anything about who you are. For
more information, see the web page for the
Gracenote Privacy Policy for the Gracenote
service.
The Gracenote Software and each item of
Gracenote Data are licensed to you "AS IS."
Gracenote makes no representations or
warranties, express or implied, regarding the
accuracy of any Gracenote Data. Gracenote
reserves the right to delete data from the
Gracenote Servers or to change data
categories for any cause that Gracenote
deems sufficient. No warranty is made that
the Gracenote Software or Gracenote Servers
are error-free or that functioning of
Gracenote Software or Gracenote Servers
will be uninterrupted. Gracenote is not
obligated to provide you with new enhanced
or additional data types or categories that
Gracenote may provide in the future and is
free to discontinue its services at any time.
GRACENOTE DISCLAIMS ALL WARRANTIES
EXPRESS OR IMPLIED, INCLUDING, BUT NOT
LIMITED TO, IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, TITLE, AND
NON-INFRINGEMENT. GRACENOTE DOES NOT
WARRANT THE RESULTS THAT WILL BE
OBTAINED BY YOUR USE OF THE GRACENOTE
SOFTWARE OR ANY GRACENOTE SERVER. IN

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
206 Climate Controls
Manual Operation
Fan Control :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. The driver
side or passenger side temperature display
shows the temperature setting increasing or
decreasing.
SYNC : Press to link the passenger and rear
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.
Changing the mode cancels the automatic
operation and the system goes into manual
mode. Press AUTO to return to automatic
operation.
To change the current mode, select one or
more of the following:
z: Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed. For best results, clear all snow and ice from
the windshield before defrosting.
@:
Press to turn on recirculation. An
indicator light comes on. Air is recirculated
to quickly cool the inside of the vehicle.
It can also be used to help reduce outside
air and odors that enter the vehicle.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning on
or off. An indicator light comes on to show
that the air conditioning is enabled. If the
fan is turned off, the air conditioner will not
run. The A/C light will stay on even if the
outside temperatures are below freezing.
Rear Window Defogger
1REAR : If equipped, press to turn the
rear window defogger on or off. An indicator
light on the button comes on to show that
the rear window defogger is on.
The rear window defogger only works when
the engine is running. The defogger turns
off if the ignition is turned off or to ACC/
ACCESSORY.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
228 Driving and Operating
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 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 button again to turn the
ignition off.
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.
SeeAdd-On Electrical Equipment 0306. Shift the vehicle into P (Park) or N (Neutral).
To restart the engine when the vehicle is
already moving, use N (Neutral) only.
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. The remote key 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 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), press the ENGINE START/
STOP position to continue engine
cranking.
Caution
Cranking the engine for long periods of
time, by trying to start the engine
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
pressing 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 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.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
240 Driving and Operating
The actual 4x4 shift request is only made
after the button is released. The 4x4 graphic
will remain flashing until the shift request
has completed.
A DIC message displays. Once the 4x4 shift
has completed, the DIC message disappears,
the 4x4 graphic stops flashing, and the
current setting is indicated.
Brakes
Electric Brake Boost
Vehicles equipped with electric brake boost
have hydraulic brake circuits that are
electronically controlled when the brake
pedal is applied during normal operation.
The system performs routine tests and turns
off within a few minutes after the vehicle is
turned off. Noise may be heard during this
time. If the brake pedal is pressed during
the tests or when the electric brake boost
system is off, a noticeable change in pedal
force and travel may be felt. This is normal.
Antilock Brake System (ABS)
The Antilock Brake System (ABS) helps
prevent a braking skid and maintain steering
while braking hard.
If there is a problem with ABS, this warning
light stays on. SeeAntilock Brake System
(ABS) Warning Light 0112.
ABS does not change the time needed to
get a foot on the brake pedal and does not
always decrease stopping distance. If you
get too close to the vehicle ahead, there will
not be enough time to apply the brakes if
that vehicle suddenly slows or stops. Always
leave enough room ahead to stop, even
with ABS.
Using ABS
Do not pump the brakes. Just hold the brake
pedal down firmly. Hearing and feeling ABS
operate is normal.
Braking in Emergencies
ABS allows steering and braking at the same
time. In many emergencies, steering can
help even more than braking.
Electric Parking Brake
The Electric Parking Brake (EPB) can always
be applied, even if the vehicle is off. In case
of insufficient electrical power, the EPB
cannot be applied or released. To prevent
draining the battery, avoid unnecessary
repeated cycles of the EPB.
The system has a red parking brake status
light and an amber service parking brake
warning light. See Electric Parking Brake
Light 0112 and
Service Electric Parking Brake Light 0112.
There are also parking brake-related Driver
Information Center (DIC) messages.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
250 Driving and Operating
Aerodynamic Height is 20 mm (0.75 in)
lower than Normal Height. This ride height
lowers the vehicle at higher vehicle speeds
to improve aerodynamics.
The vehicle will lower to Aerodynamic
Height when vehicle speed exceeds
105 km/h (65 mph) for a period of time. The
vehicle will raise to Normal Height when the
vehicle slows to less than 48 km/h
(30 mph).
Aerodynamic Height is automatically
disabled when a trailer is connected to the
vehicle or Tow/Haul Driver Mode is active.
Suspension Modes
The air suspension has two special modes
located in the infotainment screen under
Settings/Vehicle/Suspension. When either is
active, the following amber icon will be
illuminated in the instrument cluster.
SeeFour Corner Air Suspension Light 0116. Service Mode
Service Mode will disable all air suspension
operation including raising and lowering the
vehicle and operation of the air compressor.
This mode is useful when the vehicle is
being towed on a flat bed or when any
work under the vehicle is being performed.
Service Mode is automatically enabled when
the vehicle is put on a hoist or a floor jack
is used to raise a corner. Service Mode may
temporarily enable during intense off-road
situations to prevent damaging air
suspension activity. Service Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Alignment Mode
Alignment Mode will optimize the vehicle
height to provide the most accurate wheel
alignment. This mode should be enabled
once the vehicle is driven onto the
alignment station.
To enable Alignment Mode, ensure the
vehicle is at Normal Height and shift the
vehicle to Neutral. Alignment Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Air Suspension Operation with Door(s) or
Hood Open
The air suspension will temporarily suspend
all height changes while the hood or any
door is open.
System Over-Temperature
If the air suspension is under heavy use, the
system may temporarily suspend all height
changes to allow compressor cooldown.
When this occurs and a height change is
requested, a
‘Leveling System Unavailable’
message will be displayed in the instrument
cluster.
Suspension Lowered for Stability
In the event of a loss of Electronic Stability
Control, the air suspension will lower the
vehicle at higher speeds to provide increased
stability. This will be accompanied by a
‘Vehicle Lowering for Stability’ message in
the instrument cluster.
Excessive Vehicle Loading
If the air suspension detects excessive
vehicle loading, it will not raise above
Normal Height.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Driving and Operating 253
Adaptive Cruise Control
(Advanced)
If equipped with Adaptive Cruise Control
(ACC), it allows for selecting the cruise
control set speed and following gap. Read
this entire section before using this system.
ACC uses a camera and radar sensor(s) to
detect other vehicles. SeeRadio Frequency
Statement 0409.
The following gap is the following time (or
distance) between your vehicle and a vehicle
detected directly ahead in your path,
moving in the same direction. If no vehicle
is detected in your path, ACC works like
regular cruise control.
If a vehicle is detected in your path, ACC can
apply acceleration or limited, moderate
braking to maintain the selected following
gap. To disengage ACC, apply the brake.
If ACC is controlling the vehicle speed when
the Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control (ESC)
system activates, ACC may automatically
disengage. See Traction Control/Electronic
Stability Control 0242. When road
conditions allow ACC to be safely used, ACC
can be turned back on. Disabling the TCS or StabiliTrak/ESC system
will disengage and prevent engagement
of ACC.
ACC can reduce the need for you to
frequently brake and accelerate, especially
when used on expressways, freeways, and
interstate highways. When used on other
roads, you may need to take over the
control of braking or acceleration more
often.
{Warning
ACC has limited braking ability and may
not have time to slow the vehicle down
enough to avoid a collision with another
vehicle you are following. This can occur
when vehicles suddenly slow or stop
ahead, or enter your lane. Also see
“Alerting the Driver”
later in this section.
Complete attention is always required
while driving and you should be ready to
take action and apply the brakes. See
Defensive Driving 0214.
{Warning
ACC will not detect or brake for children,
pedestrians, animals, or other objects.
Do not use ACC when:
.On winding and hilly roads or when
the camera sensor is blocked by snow,
ice, or dirt. The system may not
detect a vehicle ahead. Keep the
windshield and headlamps clean.
.When visibility is poor due to rain,
snow, fog, dirt, insect residue, or dust;
when other foreign objects obscure
the camera’s view; or when the
vehicle in front or oncoming traffic
causes additional environmental
obstructions, such as road spray. ACC
performance is limited under these
conditions.
.On slippery roads where fast changes
in tire traction can cause excessive
wheel slip
.With extremely heavy cargo loaded in
the cargo area or rear seat
.When towing a trailer

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
256 Driving and Operating
The set speed can also be increased while
the vehicle is stopped.
.If stopped with the brake pedal applied,
press RES+ until the desired set speed is
displayed.
.If ACC is holding the vehicle at a stop and
there is another vehicle directly ahead,
pressing RES+ will increase the set speed.
.Pressing RES+ when there is no longer a
vehicle ahead or the vehicle ahead is
pulling away and the brake is not applied
with cause the ACC to resume.
When it is determined that there is no
vehicle ahead or the vehicle ahead is beyond
the selected following gap, then the vehicle
speed will increase to the set speed.
Reducing Speed While ACC Is at a Set Speed
If ACC is already activated, do one of the
following:
.Use the brake to get to the desired lower
speed. Release the brake and press SET–.
The vehicle will now cruise at the lower
speed.
.Press and hold SET– until the desired
lower speed is reached, then release it.
.To decrease the vehicle speed in smaller
increments, press SET− down briefly. For
each press, the vehicle goes about 1 km/h
or (1 mph) slower.
.To decrease the vehicle speed in larger
increments, hold SET−. While holding SET
−, the vehicle speed decreases to the next
5 km/h (5 mph) step, then continues to
decrease by 5 km/h (5 mph) at a time.
The set speed can also be decreased while
the vehicle is stopped.
.If stopped with the brake applied, press
or hold SET− until the desired set speed is
displayed.
Selecting the Follow Distance Gap
When a slower moving vehicle is detected
ahead within the selected following gap,
ACC will adjust the vehicle's speed and
attempt to maintain the follow distance gap
selected.
Press
[on the steering wheel to adjust
the following gap. Each press cycles the gap
button through three settings: Far, Medium,
or Near.
When pressed, the current gap setting
displays briefly on the instrument cluster
and HUD (if equipped). The gap setting will
be maintained until it is changed. Since each gap setting corresponds to a
following time (Far, Medium, or Near), the
following distance will vary based on vehicle
speed. The faster the vehicle speed, the
further back your vehicle will follow a
vehicle detected ahead. Consider traffic and
weather conditions when selecting the
following gap. The range of selectable gaps
may not be appropriate for all drivers and
driving conditions.
Changing the gap setting automatically
changes the alert timing sensitivity (Far,
Medium, or Near) for the Forward Collision
Alert (FCA) feature. See
Forward Collision
Alert (FCA) System 0267.
Alerting the Driver
With Head-Up Display

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Driving and Operating 257
Without Head-Up Display
If ACC is engaged, driver action may be
required when ACC cannot apply sufficient
braking because of approaching a vehicle
too rapidly.
When this condition occurs, the collision
alert symbol will flash on the windshield.
Either eight beeps will sound from the front,
or both sides of the Safety Alert Seat (if
equipped) will pulse five times. See
“Collision/Detection Systems” underVehicle
Personalization 0124
See Defensive Driving 0214.
Approaching and Following a Vehicle
The vehicle ahead indicator is in the
instrument cluster and HUD, if equipped.
It only displays when a vehicle is detected
in your vehicle’s path moving in the same
direction. If this symbol is not displaying,
ACC will not respond to or brake for vehicles
ahead.
ACC automatically slows the vehicle down
and adjusts vehicle speed to follow a
detected vehicle ahead at the selected
following gap. The vehicle speed increases or
decreases to follow a detected vehicle in
front of your vehicle when that vehicle is
traveling slower than your vehicle set speed.
It may apply limited braking, if necessary.
When braking is active, the brake lamps will
come on. The automatic braking may feel or
sound different than if the brakes were
applied manually. This is normal.
Passing a Vehicle While Using ACC
If the set speed is high enough, and the left
turn signal is used to pass a vehicle ahead
in the selected following gap, ACC may
assist by gradually accelerating the vehicle
prior to the lane change.{Warning
When using ACC to pass a vehicle or
perform a lane change, the following
distance to the vehicle being passed may
be reduced. ACC may not apply sufficient
acceleration or braking when passing a
vehicle or performing a lane change.
Always be ready to manually accelerate
or brake to complete the pass or lane
change.
Stationary or Very Slow-Moving Objects
{Warning
ACC may not detect and react to stopped
or slow-moving vehicles ahead of you. For
example, the system may not brake for a
vehicle it has never detected moving. This
can occur in stop-and-go traffic or when a
vehicle suddenly appears due to a vehicle
ahead changing lanes. Your vehicle may
not stop and could cause a crash. Use
caution when using ACC. Your complete
attention is always required while driving
and you should be ready to take action
and apply the brakes.