check engine light CHEVROLET SUBURBAN 2020 User Guide

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/15/19
Instruments and Controls 143
A Driver Information Center (DIC)
tire pressure message may also
display. Stop as soon as possible,
and inflate the tires to the pressure
value shown on the Tire and
Loading Information label. SeeTire
Pressure 0337.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light
will come on at every ignition cycle.
See Tire Pressure Monitor
Operation 0340.
Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working.
It also comes on when the fuel tank
is low on fuel. The light turns off
when fuel is added. If it does not,
have the vehicle serviced.
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. See
Immobilizer Operation
(Key Access) 035 or
Immobilizer Operation (Keyless
Access) 035.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0169.
IntelliBeam Light
This light comes on when the
IntelliBeam system, if equipped, is
enabled.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/24/19
276 Driving and Operating
Trailer Lamps
Always check all trailer lamps are
working at the beginning of each
trip, and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals should will illuminate to
indicate the vehicle is turning,
changing lanes, or stopping. When
towing a trailer, the arrows on the
instrument cluster will illuminate
even if the trailer is not properly
connected or the bulbs are
burned out.
Tow/Haul Mode
For instructions on how to enter
Tow/Haul mode, seeTow/Haul
Mode 0221.
Tow/Haul assists when pulling a
heavy trailer or a large or
heavy load.
Tow/Haul Mode is designed to be
most effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross Combined Weight Rating (GCWR).
See
“Maximum Trailer Weight”
under Trailer Towing 0267.
Tow/Haul Mode is most useful when
towing a heavy trailer or carrying a
large or heavy load:
. through rolling terrain
. in stop-and-go traffic
. in busy parking lots
Operating the vehicle in Tow/Haul
Mode when lightly loaded or not
towing will not cause damage;
however, it is not recommended and
may result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy.Integrated Trailer Brake
Control System
The vehicle may have an Integrated
Trailer Brake Control (ITBC) system
for use with electric trailer brakes or
most electric over hydraulic trailer
brake systems. These instructions
apply to both types of electric trailer
brakes.
This symbol is on the Trailer Brake
Control Panel on vehicles with an
ITBC system. The power output to
the trailer brakes is proportional to
the amount of vehicle braking. This
available power output to the trailer
brakes can be adjusted to a wide
range of trailering situations.
The ITBC system is integrated with
the vehicle’ s brake, anti-lock brake,
and StabiliTrak systems. In trailering
conditions that cause the vehicle’s
anti-lock brake or StabiliTrak
systems to activate, power sent to
the trailer's brakes will be
automatically adjusted to minimize
trailer wheel lock-up. This does not
imply that the trailer has StabiliTrak.
If the vehicle’s brake, anti-lock
brake, or StabiliTrak systems are
not functioning properly, the ITBC
system may not function fully or at

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/24/19
280 Driving and Operating
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
towing. If the vehicle is towing atrailer and the TSC detects that
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If equipped
with the Integrated Trailer Brake
Control (ITBC) system, and the
trailer has an electric brake system,
StabiliTrak may also apply the trailer
brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on the
instrument cluster. Reduce vehicle
speed by gradually removing your
foot from the accelerator. If trailer
sway continues, StabiliTrak can
reduce engine torque to help slow
the vehicle. TSC will not function if
StabiliTrak is turned off. See
Traction Control/Electronic Stability
Control
0229.
{Warning
Trailer sway can result in a crash
and in serious injury or death,
even if the vehicle is equipped
with TSC.
If the trailer begins to sway,
reduce vehicle speed by
gradually removing your foot from
the accelerator. Then pull over to
check the trailer and vehicle to
help correct possible causes,
including an improperly or
overloaded trailer, unrestrained
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. See Towing
Equipment 0272 for trailer ratings
and hitch setup
recommendations.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/24/19
282 Driving and Operating
Trailer tires deteriorate over time.
The trailer tire sidewall will show the
week and year the tire was
manufactured. Many trailer tire
manufacturers recommend
replacing tires more than six
years old.
Overloading is another leading
cause of trailer tire blow-outs. Never
load your trailer with more weight
than the tires are designed to
support. The load rating is located
on the trailer tire sidewall.
Always know the maximum speed
rating for the trailer tires before
driving. This may be significantly
lower than the vehicle tire speed
rating. The speed rating may be on
the trailer tire sidewall. If the speed
rating is not shown, the default
trailer tire speed rating is 105 km/h
(65 mph).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 085 and
Adding Equipment to the
Airbag-Equipped Vehicle 085.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/15/19
Vehicle Care 283
Vehicle Care
General Information
General Information . . . . . . . . . . 284
California Proposition65 Warning . . . . . . . . . . . . . . . . . 285
California Perchlorate Materials Requirements . . . . . 285
Accessories and Modifications . . . . . . . . . . . . . . . . 285
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 286
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 286
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 288
Engine Oil . . . . . . . . . . . . . . . . . . . . 293
Engine Oil Life System . . . . . . . 295
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 296
Automatic Transmission Fluid (10-Speed Transmission) . . . 299
Engine Air Cleaner/Filter . . . . . . 300
Cooling System . . . . . . . . . . . . . . 301
Engine Overheating . . . . . . . . . . 305
Engine Fan . . . . . . . . . . . . . . . . . . . 306
Washer Fluid . . . . . . . . . . . . . . . . . 306
Brakes . . . . . . . . . . . . . . . . . . . . . . . 307 Brake Fluid . . . . . . . . . . . . . . . . . . . 308
Battery - North America . . . . . . 309
Four-Wheel Drive . . . . . . . . . . . . . 310
Front Axle . . . . . . . . . . . . . . . . . . . . 310
Rear Axle . . . . . . . . . . . . . . . . . . . . . 311
Starter Switch Check . . . . . . . . . 311
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 311
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 311
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 312
Wiper Blade Replacement . . . . 312
Glass Replacement . . . . . . . . . . 313
Windshield Replacement . . . . . 313
Gas Strut(s) . . . . . . . . . . . . . . . . . . 314
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 315
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 315
Halogen Bulbs . . . . . . . . . . . . . . . . 315
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 315
LED Lighting . . . . . . . . . . . . . . . . . 315
Headlamps . . . . . . . . . . . . . . . . . . . 316
Fog Lamps . . . . . . . . . . . . . . . . . . . 316
Front Turn Signal Lamps . . . . . 316 Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 317
License Plate Lamp . . . . . . . . . . 318
Electrical System
Electrical System Overload . . . 319
Fuses and Circuit Breakers . . . 319
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 320
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 324
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 327
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 329
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 330
All-Season Tires . . . . . . . . . . . . . . 331
Winter Tires . . . . . . . . . . . . . . . . . . 331
Low-Profile Tires . . . . . . . . . . . . . 332
All-Terrain Tires . . . . . . . . . . . . . . . 332
Tire Sidewall Labeling . . . . . . . . 332
Tire Designations . . . . . . . . . . . . . 333
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 334
Tire Pressure . . . . . . . . . . . . . . . . . 337
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 338

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/15/19
308 Vehicle Care
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. SeeCapacities and
Specifications 0397.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change in many other ways if the wrong
replacement brake parts are
installed or if parts are improperly
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with GM approved DOT 3
brake fluid as indicated on the
reservoir cap. See
Engine
Compartment Overview 0288 for
the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a
level surface, the brake fluid level
should be between the minimum
and maximum marks on the brake
fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down: .
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.
. A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged. (Continued)

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13566622) - 2020 - CRC - 4/15/19
Vehicle Care 365
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
0
288.
{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.
(Continued)
Warning (Continued)
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-13566622) - 2020 - CRC - 4/15/19
Service and Maintenance 389
Additional
Maintenance and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional
maintenance services may be
required.
It is recommended that your dealer
perform these services—their
trained dealer technicians know
your vehicle best. Your dealer can
also perform a thorough
assessment with a multi-point
inspection to recommend when your
vehicle may need attention.
The following list is intended to
explain the services and conditions
to look for that may indicate
services are required.
Battery
The 12-volt battery supplies power
to start the engine and operate any
additional electrical accessories. .
To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of
cracking or splitting.
. Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary.
Brakes
Brakes stop the vehicle and are
crucial to safe driving.
. Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping. .
Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants 0392 for GM approved
fluids.
. Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled.
Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13566622) - 2020 - CRC - 4/24/19
Index 425
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 285
Accessory Power . . . . . . . . . . . . . . . 212
Active Fuel Management . . . . . . . 214
Adaptive Cruise Control . . . . . . . . 235
Add-On Electrical Equipment . . . 282
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . 416
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . . . 389
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . . 204
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 48
Air Cleaner/Filter, Engine . . . . . . . 300
Air Conditioning . . . . . . . . . . . 178, 182
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 184
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 183
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 86
How Does an AirbagRestrain? . . . . . . . . . . . . . . . . . . . . . 79
Passenger Sensing System . . . . 81
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 79 What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 79
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 78
Where Are the Airbags? . . . . . . . . 76
Airbags Adding Equipment to the
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . 85
Passenger Status Indicator . . . 136
Readiness Light . . . . . . . . . . . . . . 136
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 85
System Check . . . . . . . . . . . . . . . . . . 74
Alarm Vehicle Security . . . . . . . . . . . . . . . . 33
Alert
Lane Change . . . . . . . . . . . . . . . . . 252
Side Blind Zone (SBZA) . . . . . . 252
All-Season Tires . . . . . . . . . . . . . . . . 331
All-Terrain Tires . . . . . . . . . . . . . . . . . 332
Antilock Brake System (ABS) . . . 227 Warning Light . . . . . . . . . . . . . . . . . 140
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 371

Chevrolet Tahoe/Suburban Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13566622) - 2020 - CRC - 4/24/19
426 Index
Interior . . . . . . . . . . . . . . . . . . . . . . . . 376
Armrest Storage . . . . . . . . . . . . . . . . 111
Assistance Program,
Roadside . . . . . . . . . . . . . . . . . . . . . . 404
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . . . 248
Assistance Systems for
Parking and Backing . . . . . . . . . . 244
Automatic Door Locks . . . . . . . . . . . . . . . . . . . . . 25
Emergency Braking (AEB) . . . . 250
Headlamp System . . . . . . . . . . . . 170
Level Control . . . . . . . . . . . . . . . . . 232
Transmission . . . . . . . . . . . . . . . . . 216
Transmission Fluid . . . . . . 296, 299
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 219
Shift Lock Control FunctionCheck . . . . . . . . . . . . . . . . . . . . . . . .311
Auxiliary Roof Mounted Lamp . . . . . . . . . . 172
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 310
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 311
B
Battery Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . 176 Load Management . . . . . . . . . . . . 175
Power Protection . . . . . . . . . . . . . 176
Battery - North America . . . . 309, 363
Blade Replacement, Wiper . . . . . 312
Blind Spot Mirrors . . . . . . . . . . . . . . . 38
Brake Pedal and Adjustable
Throttle . . . . . . . . . . . . . . . . . . . . . . 204
System Warning Light . . . . . . . . 139
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 307 Antilock . . . . . . . . . . . . . . . . . . . . . . . 227
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 228
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Parking . . . . . . . . . . . . . . . . . . . . . . . 228
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 189 Automatic
Emergency (AEB) . . . . . . . . . . . 250
Break-In, New Vehicle . . . . . . . . . . 204
Bulb Replacement Fog Lamps . . . . . . . . . . . . . . . . . . . 316
Front Turn Signal Lamps . . . . . 316
Halogen Bulbs . . . . . . . . . . . . . . . . 315
Headlamp Aiming . . . . . . . . . . . . . 315
Headlamps . . . . . . . . . . . . . . 315, 316
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . . . 315
License Plate Lamps . . . . . . . . . 318 Taillamps, Turn Signal,
Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 317
Buying New Tires . . . . . . . . . . . . . . . 346
C
Calibration . . . . . . . . . . . . . . . . . . . . . . 120
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . 285
California Proposition
65 Warning . . . . . . . . . .285, 309, 363,
Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 397
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 215
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . 27
Winter Driving . . . . . . . . . . . . . . . . 197
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . .113
Caution, Danger, and Warning . . . . 2
Center Console Storage . . . . . . . . 112
Center Seat . . . . . . . . . . . . . . . . . . . . . 47
Chains, Tire . . . . . . . . . . . . . . . . . . . . 350