check engine light GMC ACADIA 2020 User Guide

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 183
{Warning
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water
can build up under the vehicle's
tires so they actually ride on the
water. This can happen if the road iswet enough and you are going fast
enough. When the vehicle is
hydroplaning, it has little or no
contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.
Allow extra following distance.
. Pass with caution.
. Keep windshield wiping
equipment in good shape.
. Keep the windshield washer fluid
reservoir filled.
. Have good tires with proper
tread depth. See Tires0297.
. Turn off cruise control.
. Activate All-Wheel Drive (AWD)
mode. See Driver Mode Control
0 212.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips include:
.
Keep the vehicle serviced and in
good shape.
. Check all fluid levels, brakes,
tires, cooling system, and
transmission.
. Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 207
may be heard while this test is going
on, and the brake pedal may move
slightly. This is normal.
If there is a problem with ABS, this
warning light stays on. SeeAntilock
Brake System (ABS) Warning Light
0 130.
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 or 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 vehicle has an Electric Parking
Brake (EPB). The EPB can always
be activated, even if the ignition is off. To prevent draining the battery,
avoid repeated cycles of the EPB
system when the engine is not
running.
The system has a
Yor PARK
Electric Parking Brake light, and a
8
Service Parking Brake light or
message. See Electric Parking
Brake Light 0130 and
Service Electric Parking Brake Light
(Uplevel and Midlevel Cluster Only)
0 130.
Before leaving the vehicle, check for
the
Yor PARK light to ensure that
the parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The
Yor PARK light will flash and
then stay on once the EPB is fully
applied. If the
Yor PARK light
flashes continuously, then the EPB
is only partially applied or there is a

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
210 Driving and Operating
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.
If cruise control is being used and
TCS or StabiliTrak/ESC begins to
limit wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road
conditions allow. TCS and
StabiliTrak/ESC will automatically
turn on when cruise control is set.
Both systems come on
automatically when the vehicle is
started and begins to move. The
systems may be heard or felt while
they are operating or while
performing diagnostic checks. This
is normal and does not mean there
is a problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary
to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow.
SeeIf the Vehicle Is Stuck 0185
and “Turning the Systems Off and
On” later in this section.
The indicator light for both systems
is in the instrument cluster. This
light:
.
Will flash when TCS is limiting
wheel spin
. Will flash when StabiliTrak/ESC
is activated
. Will turn on and stay on when
either system is not working
. May flash when ABS is active
If either system fails to turn on or to
activate, a message may display in
the Driver Information Center (DIC),
and
dcomes on and stays on to
indicate that the system is inactive
and is not assisting the driver in
maintaining control. The vehicle is
safe to drive, but driving should be
adjusted accordingly. If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
4. Drive the vehicle.
If
dcomes on and stays on, the
vehicle may need more time to
diagnose the problem. If the
condition persists, see your dealer.
Turning the Systems Off
and On

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
256 Driving and Operating
Electric Trailer
BrakesBlue
Battery Feed Red/Black or
Red/Blue
Brake Apply
Signal White/Blue
Ground Black
Refer to the aftermarket electric
trailer brake controller owner's
manual to determine wire color
coding of the electric trailer brake
controller. The wire colors on the
brake controller may be different
from the vehicle. It may be
necessary to have a technician
connect the 12-volt power to the
engine compartment fuse block. The
electric trailer brake controller
should be installed by your dealer or
a qualified service center.
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, see Driver Mode
Control 0212.
Tow/Haul assists when pulling a
heavy trailer or a large or heavy
load. See Tow/Haul Mode 0206.
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 “Weight of the Trailer” under
Trailer Towing 0250. 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.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak/Electronic
Stability Control (ESC) 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 a
trailer 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

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Driving and Operating 257
Control (ITBC) system, and the
trailer has an electric brake system,
StabiliTrak/ESC may also apply the
trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak/
ESC warning light will flash on the
instrument cluster. Reduce vehicle
speed by gradually removing your
foot from the accelerator. If trailer
sway continues, StabiliTrak/ESC
can reduce engine torque to help
slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned
off. SeeTraction Control/Electronic
Stability Control 0209.
{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 0253 for trailer ratings
and hitch setup
recommendations.
Trailer Tires
Special Trailer (ST) tires differ from
vehicle tires. Trailer tires are
designed with stiff sidewalls to help
prevent sway and to support heavy
loads. These features can make it
difficult to determine if the trailer tire
pressures are low only based on a
visual inspection.
Always check all trailer tire
pressures before each trip when the
tires are cool. Low trailer tire
pressure is a leading cause of trailer
tire blow-outs.
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
258 Driving and Operating
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. See
Malfunction Indicator Lamp
(Check Engine Light)0127.
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 075 and
Adding Equipment to the
Airbag-Equipped Vehicle 076.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Vehicle Care 259
Vehicle Care
General Information
General Information . . . . . . . . . . 260
California Proposition65 Warning . . . . . . . . . . . . . . . . . 260
California Perchlorate Materials Requirements . . . . . 261
Accessories and Modifications . . . . . . . . . . . . . . . . 261
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 261
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 262
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 264
Engine Oil . . . . . . . . . . . . . . . . . . . . 269
Engine Oil Life System . . . . . . . 271
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 272
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 273
Engine Air Cleaner/Filter . . . . . . 273
Cooling System . . . . . . . . . . . . . . 275
Engine Overheating . . . . . . . . . . 279
Washer Fluid . . . . . . . . . . . . . . . . . 281
Brakes . . . . . . . . . . . . . . . . . . . . . . . 281
Brake Fluid . . . . . . . . . . . . . . . . . . . 282 Battery - North America . . . . . . 283
All-Wheel Drive . . . . . . . . . . . . . . . 284
Starter Switch Check . . . . . . . . . 284
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 285
Wiper Blade Replacement . . . . 285
Windshield Replacement . . . . . 286
Gas Strut(s) . . . . . . . . . . . . . . . . . . 286
Headlamp Aiming
Front Headlamp Aiming . . . . . . 288
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 288
Halogen Bulbs . . . . . . . . . . . . . . . . 288
LED Lighting . . . . . . . . . . . . . . . . . 288
Electrical System
Electrical System Overload . . . 289
Fuses and Circuit Breakers . . . 289
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 290
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 293
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 295
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 297
All-Season Tires . . . . . . . . . . . . . . 298
Winter Tires . . . . . . . . . . . . . . . . . . 299
Summer Tires . . . . . . . . . . . . . . . . 299 Tire Sidewall Labeling . . . . . . . . 300
Tire Designations . . . . . . . . . . . . . 302
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 302
Tire Pressure . . . . . . . . . . . . . . . . . 305
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . 306
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 307
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . 308
Tire Inspection . . . . . . . . . . . . . . . . 312
Tire Rotation . . . . . . . . . . . . . . . . . 312
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . 313
Buying New Tires . . . . . . . . . . . . . 314
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . 315
Uniform Tire Quality Grading . . . . . . . . . . . . . . . . . . . . . 316
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . 317
Wheel Replacement . . . . . . . . . . 318
Tire Chains . . . . . . . . . . . . . . . . . . . 318
If a Tire Goes Flat . . . . . . . . . . . . 319
Tire Sealant and Compressor Kit . . . . . . . . . . . . . 321
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . 327
Tire Changing . . . . . . . . . . . . . . . . 328

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
282 Vehicle Care
{Warning
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
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. See
Capacities and
Specifications 0366.
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 0264 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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13687875) - 2020 - CRC - 10/28/19
Service and Maintenance 359
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 0362 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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13687875) - 2020 - CRC - 10/28/19
Index 393
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 261
Accessory Power . . . . . . . . . . . . . . . 196
Active Fuel Management . . . . . . . 199
Adaptive Cruise Control . . . . . . . . 216
Add-On Electrical Equipment . . . 258
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . 386
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . . . 359
Adjustments Lumbar, Front Seats . . . . . . . . . . . . 45
Air Cleaner/Filter, Engine . . . . . . . 273
Air Conditioning . . . . . . . . . . . 165, 169
Air Filter
Life System . . . . . . . . . . . . . . . . . . . 273
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 172
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 171
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 77
How Does an AirbagRestrain? . . . . . . . . . . . . . . . . . . . . . 69
Passenger Sensing System . . . . 71
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 69 Airbag System (cont'd)
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 70
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 68
Where Are the Airbags? . . . . . . . . 66
Airbags
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 76
Passenger Status Indicator . . . 126
Readiness Light . . . . . . . . . . . . . . 126
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 75
System Check . . . . . . . . . . . . . . . . . . 64
Alarm Vehicle Security . . . . . . . . . . . . . . . . 29
Alert Lane Change . . . . . . . . . . . . . . . . . 238
Side Blind Zone (SBZA) . . . . . . 238
All-Season Tires . . . . . . . . . . . . . . . . 298
All-Wheel Drive . . . . . . . . . . . . 206, 284
Antilock Brake System (ABS) . . . 206 Warning Light . . . . . . . . . . . . . . . . . 130
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 342
Interior . . . . . . . . . . . . . . . . . . . . . . . . 346
Armrest Storage . . . . . . . . . . . . . . . . . 99