2021 CHEVROLET TAHOE Check transmission

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
308 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . 309
California Proposition 65 Warning . . . . . 309
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . 309
Accessories and Modifications . . . . . . . . . 309
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 310
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Engine Compartment Overview . . . . . . . . 312
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Engine Oil Life System . . . . . . . . . . . . . . . . . 316
Automatic Transmission Fluid . . . . . . . . . . 317
Engine Air Filter Life System . . . . . . . . . . . 318
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 318
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 319
Engine Overheating . . . . . . . . . . . . . . . . . . . . 322
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Brake Pad Life System . . . . . . . . . . . . . . . . . 325
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Battery - North America . . . . . . . . . . . . . . . 327
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 327
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 Park Brake and P (Park) Mechanism
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Wiper Blade Replacement . . . . . . . . . . . . . 329
Glass Replacement . . . . . . . . . . . . . . . . . . . . 330
Windshield Replacement . . . . . . . . . . . . . . 330
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 331
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 331
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Taillamps, Turn Signal, Stoplamps, and Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . . 331
Electrical System
Electrical System Overload . . . . . . . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . . . . . . . 333
Engine Compartment Fuse Block . . . . . . . 333
Instrument Panel Fuse Block . . . . . . . . . . . 337
Rear Compartment Fuse Block . . . . . . . . . 339
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 342
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Low-Profile Tires . . . . . . . . . . . . . . . . . . . . . . . 342
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . 342
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 343
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 344
Tire Terminology and Definitions . . . . . . 344 Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . . . . . . . 348
Tire Pressure Monitor Operation . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . . 351
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 352
When It Is Time for New Tires . . . . . . . . 353
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 353
Different Size Tires and Wheels . . . . . . . 354
Uniform Tire Quality Grading . . . . . . . . . . 355
Wheel Alignment and Tire Balance . . . . 356
Wheel Replacement . . . . . . . . . . . . . . . . . . . 356
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 357
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 358
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 368
Jump Starting
Jump Starting - North America . . . . . . . . 369
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 372
Recreational Vehicle Towing . . . . . . . . . . . 373
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 376
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 380
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Vehicle Care 317
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
On some vehicles, when the system has
calculated that oil life has been diminished,
a CHANGE ENGINE OIL SOON message comes
on to indicate that an oil change is
necessary. Change the oil as soon as
possible within the next 1 000 km (600 mi).
It is possible that, if driving under the best
conditions, the oil life system might indicate
that an oil change is not necessary for up to
a year. The engine oil and filter must be
changed at least once a year and, at this
time, the system must be reset. For vehicles
without the CHANGE ENGINE OIL SOON
message, an oil change is needed when the
REMAINING OIL LIFE percentage is near 0%.
Your dealer has trained service people who
will perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To reset the
engine oil life system:
1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
0 119.
2. Press the thumbwheel on the steering wheel, or the trip odometer reset stem if
the vehicle does not have DIC controls,
for several seconds. When the
confirmation message displays, select
YES. The oil life will change to 100%.
The oil life system can also be reset as
follows: 1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
0 119.
2. Fully press the accelerator pedal slowly three times within five seconds. 3. If the display changes to 100%, the
system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid
in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See Publication Ordering
Information 0408.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
318 Vehicle Care
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. SeeRecommended Fluids and
Lubricants 0395.
Change the fluid and filter at the scheduled
maintenance intervals listed in Maintenance
Schedule 0386. Be sure to use the
transmission fluid listed in Recommended
Fluids and Lubricants 0395.
Engine Air Filter Life System
If equipped, this feature provides the engine
air filter’s remaining life and best timing for
a change. The timing to change an engine
air filter depends on driving and
environmental conditions.
When to Change the Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing. When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset the Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) 0119.
3. Press the thumbwheel on the steering wheel to move to the Reset/Disable
display area. Select Reset then press the
thumbwheel for several seconds.
4. Press the thumbwheel to confirm the reset.
Engine Air Cleaner/Filter
The engine air cleaner/filter is on the driver
side of the engine compartment. See Engine
Compartment Overview 0312.
When to Inspect the Engine Air Cleaner/
Filter
If the vehicle is not equipped with the
engine air filter life system see Maintenance
Schedule 0386 for intervals on inspecting
and replacing the engine air cleaner filter.
How to Inspect/Replace the Engine Air
Cleaner/Filter
Do not start the engine or have the engine
running with the engine air cleaner/filter
housing open. Before removing the engine
air cleaner/filter, make sure that the engine
air cleaner/filter housing and nearby
components are free of dirt and debris. Do
not clean the engine air cleaner/filter or
components with water or compressed air.
To inspect or replace the engine air cleaner/
filter:

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Vehicle Care 329
.To check the parking brake's holding
ability: With the engine running and the
transmission in N (Neutral), slowly remove
foot pressure from the regular brake
pedal. Do this until the vehicle is held by
the parking brake only.
.To check the P (Park) mechanism's holding
ability: With the engine running, shift to
P (Park). Then release the parking brake
followed by the regular brake.
Contact your dealer if service is required.
Wiper Blade Replacement
Windshield wiper blades should be inspected
for wear or cracking.
For the proper type and size, see
Maintenance Replacement Parts 0396.
Caution
Allowing the wiper arm to touch the
windshield when no wiper blade is
installed could damage the windshield.
Any damage that occurs would not be
covered by the vehicle warranty. Do not
allow the wiper arm to touch the
windshield.
Front Wiper Blade Replacement
To replace the wiper blade assembly:
1. Pull the windshield wiper assembly away from the windshield.
2. Press the button in the middle of thewiper arm connector, and pull the wiper
blade away from the arm connector.
3. Remove the wiper blade.
4. Reverse Steps 1–3 for wiper blade replacement.
Rear Wiper Blade Replacement
To replace the rear wiper blade: 1. With the rear wiper in the off position,
open the liftglass to access the rear
wiper arm/blade.
The rear wiper blade will not lock in a
vertical position so use care when pulling
it away from the vehicle.
2. Push the release lever (2) to disengagethe hook and push the wiper arm (1) out
of the blade assembly (3).
3. Push the new blade assembly securely in the wiper arm hook until the release
lever clicks into place.
4. Return the wiper arm and blade assembly to the rest position on the
glass.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Vehicle Care 371
If they are, it could cause an unwanted
ground connection. You would not be
able to start your vehicle, and the bad
grounding could damage the electrical
systems.
To avoid the possibility of the vehicles
rolling, set the parking brake firmly on
both vehicles involved in the jump start
procedure. Put an automatic transmission
in P (Park) or a manual transmission in
Neutral before setting the parking brake.
If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear,
not in N (Neutral).
Caution
If any accessories are left on or plugged
in during the jump starting procedure,
they could be damaged. The repairs
would not be covered by the vehicle
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off on both vehicles. Unplug unnecessary accessories plugged
into the accessory power outlets. Turn
off the radio and all the lamps that are not needed. This will avoid sparks and
help save both batteries. And it could
save the radio!
5. Open the hood on the other vehicle and locate the positive (+) and negative (−)
terminal locations on that vehicle.
The positive (+) terminal is under a red
plastic cover at the positive battery post.
To uncover the positive (+) terminal,
open the red plastic cover.
For more information on the location of
the remote positive (+) and remote
negative (−) terminals, see Engine
Compartment Overview 0312.{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
6. Check that the jumper cables do not have loose or missing insulation. If they
do, you could get a shock. The vehicles
could be damaged too.
Before you connect the cables, here are
some basic things you should know.
Positive (+) will go to positive (+) or to a
remote positive (+) terminal if the

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
374 Vehicle Care
Dinghy Towing
Two-Wheel-Drive Vehicles
Caution
If the two-wheel-drive vehicle is towed
with all four wheels on the ground, the
drivetrain components could be damaged.
The repairs would not be covered by the
vehicle warranty.
Two-wheel-drive vehicles should not be
towed with all four wheels on the ground. Four-Wheel-Drive Vehicles
Only dinghy tow four-wheel-drive vehicles
with a two speed transfer case that has an
N (Neutral) and a 4
nsetting.
{Warning
Shifting a four-wheel-drive vehicle's
transfer case into N (Neutral) can cause
the vehicle to roll even if the
transmission is in P (Park). You or others
could be injured. Set the parking brake
before shifting the transfer case to
N (Neutral).To dinghy tow:
1. Position the vehicle being towed behind the tow vehicle, facing forward and on a
level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into N (Neutral)” under
Four-Wheel Drive 0236 for the proper
procedure. Check that the vehicle is in
N (Neutral) by shifting the transmission
to R (Reverse) and then to D (Drive).
There should be no movement of the
vehicle while shifting.
5. Shift the transmission to P (Park).Caution
Failure to tow the vehicle with the
transmission in P (Park) can cause
damage to the transmission.
6. Turn off the engine.
7. Place the vehicle in ACC/ACCESSORY mode by pressing the start button
without stepping on the brake pedal.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
Vehicle Care 375
8. Release the parking brake only when youare confident it is secured to tow vehicle
and will not roll.
Before going on to the next step, be
sure to take the mechanical key with
you. It will be needed to re-enter the
vehicle after the power is disconnected.
See “Drive Door Key Lock Cylinder
Access” underDoor Locks 015.
9. Disconnect the negative battery cable at the battery and secure the nut and bolt.
Cover the negative battery post with a
non-conductive material to prevent any
contact with the negative battery
terminal.
Caution
Failure to disconnect the negative battery
cable or to have it contact the terminals
can cause damage to the vehicle.
10. Move the steering wheel to make sure the steering column is unlocked.
Caution
If the steering column is locked, vehicle
damage may occur. 11. Rock the vehicle to make sure the
parking brake is not set and transfer case
is in N (Neutral).
Caution
Towing the vehicle with the parking
brake set can damage it. Always release
the parking brake prior to towing the
vehicle.
Disconnecting the Towed Vehicle
Before disconnecting the towed vehicle: 1. Park on a level surface.
2. Connect the battery.
3. Apply the brake pedal.
{Warning
The vehicle can roll when the brake pedal
is released. Always apply and hold the
brake pedal when setting the parking
brake. Make sure the parking brake is
fully engaged before releasing the brake
pedal.
4. Start the engine and shift the transfer case out of N (Neutral) to 2
m. See “Shifting out of N (Neutral)”
under
Four-Wheel Drive 0236. See your dealer
if the transfer case cannot be shifted out
of N (Neutral).
5. Check that the vehicle is in 2
mby
shifting the transmission to R (Reverse)
and then to D (Drive). There should be
movement of the vehicle while shifting.
6. Shift the transmission to P (Park) and turn off the vehicle.
7. Set the parking brake.
8. Release the parking brake.
9. Disconnect the vehicle from the tow vehicle.
10. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13690484) - 2021 - crc - 8/17/20
388 Service and Maintenance
.Check restraint system components. See
Safety System Check058.
.Visually inspect fuel system for damage
or leaks.
.Visually inspect exhaust system and
nearby heat shields for loose or damaged
parts.
.Lubricate body components. See Exterior
Care 0376.
.Check parking brake and automatic
transmission park mechanism. See Park
Brake and P (Park) Mechanism Check
0 328.
.Check accelerator pedal for damage, high
effort, or binding. Replace if needed.
.Visually inspect gas strut for signs of
wear, cracks, or other damage. Check the
hold open ability of the strut. If the hold
open is low, service the gas strut. See Gas
Strut(s) 0330.
.Inspect sunroof track and seal,
if equipped. See Sunroof034.
.Verify spare tire key lock operation and
lubricate as needed. See Tire Changing
0 358.
.Visually inspect the spare tire to ensure
that it is tightly stowed under the vehicle.
Push, pull, and try to turn the tire. If the
spare tire moves, tighten as necessary.
See Tire Changing 0358.