2021 GMC ACADIA check engine

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
218 Driving and Operating
able to release the EPB using the EPB
switch. It should automatically release when
the vehicle is shifted out of P (Park).
Leaving the Vehicle with the Engine
Running
{Warning
It can be dangerous to leave the vehicle
with the engine running. It could
overheat and catch fire.
It is dangerous to get out of the vehicle
if the vehicle is not in P (Park) with the
parking brake 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 shift
the vehicle to P (Park). SeeShifting Into
Park 0217. If you are towing a trailer,
see Driving Characteristics and Towing
Tips 0256. If you have to leave the vehicle with the
engine running, the vehicle must be in
P (Park) with the parking brake set.
Confirm that the vehicle is in P (Park).
Torque Lock
Torque lock is when the weight of the
vehicle puts too much force on the parking
pawl in the transmission. This happens when
parking on a hill and shifting the
transmission into P (Park) is not done
properly and then it is difficult to shift out
of P (Park). To prevent torque lock, set the
parking brake and then shift into P (Park). To
find out how, see
“Shifting Into Park” listed
previously.
On certain steep grades, the transmission
will automatically set the parking brake to
prevent torque lock.
If torque lock does occur, the vehicle may
need to be pushed uphill by another vehicle
to relieve the parking pawl pressure, so you
can shift out of P (Park).
Shifting out of Park
This vehicle is equipped with an electronic
transmission. If the vehicle has an
uncharged battery or a battery with low
voltage, try charging or jump starting the
battery. See Jump Starting - North America
0 332.
To shift out of P (Park): 1. Ensure the engine is running.
2. Apply the brake pedal.
3. Press or pull the desired shift switch on the center stack.
The P indicator will turn white and the gear
indicator will turn red when the vehicle is
no longer in P (Park).
If the vehicle cannot shift from P (Park), a
Driver Information Center (DIC) message will
be displayed. Check that the ignitionis on,
the engine is running, and the brake pedal
is applied when you are attempting to shift
out of P (Park). If all of these are met but
the vehicle will not shift out of P (Park), see
your dealer for service.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 227
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 0209 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
d
comes 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
Caution
Do not repeatedly brake or accelerate
heavily when TCS is off. The vehicle
driveline could be damaged.
To turn off only TCS, press and release
g.
The Traction Off light
idisplays in the
instrument cluster and a DIC message may
display.
To turn TCS on again, press and release
g.
The Traction Off light
idisplayed in the
instrument cluster will turn off.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
258 Driving and Operating
Before driving, inspect all trailer hitch parts
and attachments, safety chains, electrical
connectors, lamps, tires, and mirrors. See
Towing Equipment0262. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer
brake controller to check the trailer brakes
work. During the trip, occasionally check
that the cargo and trailer are secure and
that the lamps and any trailer brakes are
working.
Towing with a Stability Control System
When towing, the stability control system
might be heard. The system reacts to
vehicle movement caused by the trailer,
which mainly occurs during cornering. This is
normal when towing heavier trailers.
Following Distance
Stay at least twice as far behind the vehicle
ahead as you would when driving without a
trailer. This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination of the
vehicle and trailer will not accelerate as
quickly and is much longer than the vehicle
alone. It is necessary to go much farther
beyond the passed vehicle before returning
to the lane. Pass on level roadways. Avoid
passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel with
one hand. To move the trailer to the left,
move that hand to the left. To move the
trailer to the right, move that hand to the
right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Caution
Turn more slowly and make wider arcs
when towing a trailer to prevent damage
to your vehicle. Making very sharp turns
could cause the trailer to contact the
vehicle. Make wider turns than normal when towing,
so the trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency.
The vehicle can tow in D (Drive). Shift the
transmission to a lower gear if the
transmission shifts too often under heavy
loads and/or hilly conditions.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, preferably on level ground, with the
transmission in P (Park) for a few minutes
before turning the engine off. If the
overheat warning comes on, see
Engine
Overheating 0285.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 259
Viewing Systems
If equipped, the viewing systems on the
vehicle can improve visibility while hitching,
backing, and driving with a trailer. See
Driver Assistance Systems0239 and
Assistance Systems for Parking or Backing
0 241.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.
When parking your vehicle and your trailer
on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the wheels into
the curb if facing downhill or into traffic
if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, gradually release the brake pedal to
allow the chocks to absorb the load of
the trailer. 4. Reapply the brake pedal. Then apply the
parking brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal:
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0346. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically that all nuts and bolts on
the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0285.
Trailer Towing
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity for
your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades, outside
temperature, dimensions of the front of the
trailer, and how frequently the vehicle is
used to tow a trailer.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
264 Driving and Operating
1. Left Turn/Brake
2. Tail Lamps
3. Reverse Lamps
4. Battery feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
If the vehicle is not equipped with a trailer
connector on the trailer hitch, a 7-wire
trailering harness is tied to the vehicles
frame. The harness requires the installation
of a trailer connector, which is available
through your dealer.Use only a round, seven-wire connector with
flat blade terminals meeting SAE J2863
specifications for proper electrical
connectivity.
The seven-wire harness contains the
following trailer circuits:
Stop/Turn
Signal Left Yellow/Gray
Stop/Turn Signal
Right Green/Violet
Tail/Parking Lamps Gray/Brown
Reverse Lamps White/Green
Battery Feed Red/Green
Ground Black
Electric Trailer Brake Blue Electric Brake Control Wiring Provisions
If equipped, (4) blunt-cut wires are located
near the driver's feet for an aftermarket
electric trailer brake controller as part of the
trailer wiring package. The harness contains
the following circuits:
Electric Trailer
Brakes Blue
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.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Driving and Operating 265
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, seeDriver Mode Control 0228.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load. See Tow/
Haul Mode 0224.
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 0259.
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
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. See
Traction Control/Electronic Stability Control
0
226.
{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 0262 for trailer
ratings and hitch setup recommendations.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
266 Driving and Operating
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.
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 onthe 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) 0107
. 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 063 and
Adding Equipment to the Airbag-Equipped
Vehicle 063.

GMC Acadia/Acadia Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-14608671) - 2021 - CRC - 10/26/20
Vehicle Care 267
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 268
California Proposition 65 Warning . . . . . 268
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . 268
Accessories and Modifications . . . . . . . . . 268
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 269
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Engine Compartment Overview . . . . . . . . 271
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Engine Oil Life System . . . . . . . . . . . . . . . . 278
Automatic Transmission Fluid . . . . . . . . . 279
Engine Air Filter Life System . . . . . . . . . . 279
Engine Air Cleaner/Filter . . . . . . . . . . . . . . 279
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 281
Engine Overheating . . . . . . . . . . . . . . . . . . . 285
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Battery - North America . . . . . . . . . . . . . . . 288
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . 289
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Wiper Blade Replacement . . . . . . . . . . . . . 290
Windshield Replacement . . . . . . . . . . . . . . 290
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 292
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 292
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 292
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Electrical System
Electrical System Overload . . . . . . . . . . . . 292
Fuses and Circuit Breakers . . . . . . . . . . . . . 293
Engine Compartment Fuse Block . . . . . . 293
Instrument Panel Fuse Block . . . . . . . . . . 296
Rear Compartment Fuse Block . . . . . . . . . 298
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 301
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
Summer Tires . . . . . . . . . . . . . . . . . . . . . . . . . 302
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . 302
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 302
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 304
Tire Terminology and Definitions . . . . . 304
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Tire Pressure Monitor System . . . . . . . . . 309
Tire Pressure Monitor Operation . . . . . . . 310
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . . 313
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 When It Is Time for New Tires . . . . . . . . . 314
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 315
Different Size Tires and Wheels . . . . . . . . 316
Uniform Tire Quality Grading . . . . . . . . . . 316
Wheel Alignment and Tire Balance . . . . 318
Wheel Replacement . . . . . . . . . . . . . . . . . . . 318
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 319
Tire Sealant and Compressor Kit . . . . . . 320
Storing the Tire Sealant and
Compressor Kit . . . . . . . . . . . . . . . . . . . . . . 326
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 326
Compact Spare Tire . . . . . . . . . . . . . . . . . . . . 331
Jump Starting
Jump Starting - North America . . . . . . . . 332
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . . 334
Recreational Vehicle Towing . . . . . . . . . . . 335
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343