2021 GMC YUKON low oil pressure

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 321
Never dispose of engine coolant by putting
it in the trash, or by pouring it on the
ground, or into sewers, streams, or bodies of
water. Have the coolant changed by an
authorized service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant
The coolant surge tank is in the engine
compartment on the driver side of the
vehicle. SeeEngine Compartment Overview
0 312.
The vehicle must be on a level surface when
checking the coolant level.
5.3L V8 Engine Shown, 6.2L V8 Engine Similar Check to see if coolant is visible in the
coolant surge tank. If the coolant inside the
coolant surge tank is boiling, wait until it
cools down. The coolant level should be at
or above the indicated mark. If it is not,
there may be a leak in the cooling system.
If coolant is visible but the coolant level is
not at or above the indicated mark, see the
following sections on how to add coolant to
the coolant surge tank following.
How to Add Coolant to the Coolant
Surge Tank
If the vehicle has a diesel engine, see
“Cooling System”
in the Duramax diesel
supplement for the proper coolant fill
procedure.
{Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 375
Rinse the vehicle well, before washing and
after, to remove all cleaning agents
completely. If they are allowed to dry on
the surface, they could stain.
Dry the finish with a soft, clean chamois or
an all-cotton towel to avoid surface
scratches and water spotting.
Cleaning Underhood Components
Caution
Do not power wash any component
under the hood that has this
e
symbol.
This could cause damage that would not
be covered by the vehicle warranty.
Solvents or aggressive cleaners may harm
underhood components. The usages of these
chemicals should be avoided.
Recommend water only.
A pressure washer may be used, but care
must be utilized. The following criteria must
be followed:
.Water pressure must be kept below
14,000 KPa (2,000 PSI).
.Water temperature must be below 80 °C
(180 °F).
.Spray nozzle with a 40 degree wide angle
spray pattern or wider must be used.
.Nozzle must be kept at least 30 cm (1 ft)
away from all surfaces.
Finish Care
Application of aftermarket clearcoat sealant/
wax materials is not recommended.
If painted surfaces are damaged, see your
dealer to have the damage assessed and
repaired. Foreign materials such as calcium
chloride and other salts, ice melting agents,
road oil and tar, tree sap, bird droppings,
chemicals from industrial chimneys, etc., can
damage the vehicle's finish if they remain
on painted surfaces. Wash the vehicle as
soon as possible. If necessary, use
non-abrasive cleaners that are marked safe
for painted surfaces to remove foreign
matter.
Occasional hand waxing or mild polishing
should be done to remove residue from the
paint finish. See your dealer for approved
cleaning products.
Do not apply waxes or polishes to uncoated
plastic, vinyl, rubber, decals, simulated
wood, or flat paint as damage can occur.
Caution
Machine compounding or aggressive
polishing on a basecoat/clearcoat paint
finish may damage it. Use only
non-abrasive waxes and polishes that are
made for a basecoat/clearcoat paint finish
on the vehicle.
To keep the paint finish looking new, keep
the vehicle garaged or covered whenever
possible.
Protecting Exterior Bright Metal Moldings
Caution
Failure to clean and protect the bright
metal moldings can result in a hazy
white finish or pitting. This damage
would not be covered by the vehicle
warranty.
The bright metal moldings on the vehicle
are aluminum, chrome or stainless steel. To
prevent damage always follow these
cleaning instructions:
.Be sure the molding is cool to the touch
before applying any cleaning solution.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Vehicle Care 379
Use cleaners specifically designed for the
surfaces being cleaned to prevent
permanent damage. Apply all cleaners
directly to the cleaning cloth. Do not spray
cleaners on any switches or controls.
Remove cleaners quickly.
Before using cleaners, read and follow all
safety instructions on the label. While
cleaning the interior, open the doors and
windows to get proper ventilation.
To prevent damage, do not clean the
interior using the following cleaners or
techniques:
.Never use a razor or any other sharp
object to remove soil from any interior
surface.
.Never use a brush with stiff bristles.
.Never rub any surface aggressively or
with too much pressure.
.Do not use laundry detergents or
dishwashing soaps with degreasers. For
liquid cleaners, use approximately
20 drops per 3.8 L (1 gal) of water.
A concentrated soap solution will create
streaks and attract dirt. Do not use
solutions that contain strong or
caustic soap.
.Do not heavily saturate the upholstery
when cleaning.
.Do not use solvents or cleaners containing
solvents.
Interior Glass
To clean, use a terry cloth fabric dampened
with water. Wipe droplets left behind with a
clean dry cloth. If necessary, use a
commercial glass cleaner after cleaning with
plain water.
Caution
To prevent scratching, never use abrasive
cleaners on automotive glass. Abrasive
cleaners or aggressive cleaning may
damage the rear window defogger.
Cleaning the windshield with water during
the first three to six months of ownership
will reduce tendency to fog.
Speaker Covers
Vacuum around a speaker cover gently, so
that the speaker will not be damaged. Clean
spots with water and mild soap.
Coated Moldings
Coated moldings should be cleaned.
.When lightly soiled, wipe with a sponge
or soft, lint-free cloth dampened with
water.
.When heavily soiled, use warm soapy
water.
Fabric/Carpet/Suede
Start by vacuuming the surface using a soft
brush attachment. If a rotating vacuum
brush attachment is being used, only use it
on the floor carpet. Before cleaning, gently
remove as much of the soil as possible:
.Gently blot liquids with a paper towel.
Continue blotting until no more soil can
be removed.
.For solid soils, remove as much as
possible prior to vacuuming.
To clean: 1. Saturate a clean, lint-free colorfast cloth with water. Microfiber cloth is
recommended to prevent lint transfer to
the fabric or carpet.
2. Remove excess moisture by gently wringing until water does not drip from
the cleaning cloth.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
Service and Maintenance 385
last service. Reset the oil life system when
the oil is changed. SeeEngine Oil Life
System 0316.
Engine Air Filter Change
When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the engine
air filter should be replaced at the earliest
convenience. Reset the engine air filter life
system after the engine air filter is replaced.
See Engine Air Filter Life System 0318.
Extended Idle Use
When the vehicle is used in a way that
requires extended idle time, one hour of use
shall be deemed the same as 53 km (33 mi).
See Driver Information Center (DIC) 0120 for
hourmeter.
Air Conditioning Desiccant (Replace Every
Seven Years)
The air conditioning system requires
maintenance every seven years. This service
requires replacement of the desiccant to
help the longevity and efficient operation of
the air conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required Services
Every 12 000 km/7,500 mi
Rotate the tires, if recommended for the
vehicle, and perform the following services.
See Tire Rotation 0350.
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system.
See Engine Oil 0315 and
Engine Oil Life System 0316.
.If equipped with the engine air filter life
system, check the air filter
life percentage. If necessary, replace the
engine air filter and reset the engine air
filter life system. See Engine Air Filter Life
System 0318. If the vehicle is not
equipped with the engine air filter life
system, inspect the engine air cleaner
filter. See Engine Air Cleaner/Filter 0318.
.Check engine coolant level. See Cooling
System 0319.
.Check windshield washer fluid level. See
Washer Fluid 0324.
.Check tire inflation pressures, including
the spare. See Tire Pressure0344.
.Inspect tire wear. See Tire Inspection
0 349.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior Care
0 374.
.Visually inspect steering, suspension, and
chassis components for damage, including
cracks or tears in the rubber boots, loose
or missing parts, or signs of wear at least
once a year. See Exterior Care0374.
Lubricate the suspension and steering
components at least every other oil
change (if equipped with grease fittings).
.Inspect power steering for proper
attachment, connections, binding, leaks,
cracks, chafing, etc.
.Visually inspect halfshafts and drive
shafts for excessive wear, lubricant leaks,
and/or damage including: tube dents or
cracks, constant velocity joint or universal
joint looseness, cracked or missing boots,
loose or missing boot clamps, center
bearing excessive looseness, loose or
missing fasteners, and axle seal leaks.
.Check restraint system components. See
Safety System Check 059.
.Visually inspect fuel system for damage
or leaks.
.Visually inspect exhaust system and
nearby heat shields for loose or damaged
parts.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
388 Service and Maintenance
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) Or every two years, whichever comes
first. More frequent passenger compartment
air filter replacement may be needed if
driving in areas with heavy traffic, poor air
quality, high dust levels, or environmental
allergens. Passenger compartment air filter
replacement may also be needed if there is
reduced airflow, window fogging, or odors.
Your GM dealer can help determine when to
replace the filter.
(2) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition. (3)
Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 318.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the transfer case fluid.
Contaminated fluid will decrease the life of
the transfer case and/or axles and should be
replaced.
(5) Or every five years, whichever comes
first. See Cooling System 0319. (6)
Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0326.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0329.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0330.
(10) Replace air conditioning desiccant every
seven years.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
390 Service and Maintenance
(2)Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(3) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 318.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the transfer case fluid.
Contaminated fluid will decrease the life of
the transfer case and/or axles and should be
replaced.
(5) Or every five years, whichever comes
first. See Cooling System 0319.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0326.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0329.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0330. (10)
Replace air conditioning desiccant every
seven years.
Special Application Services
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See "Underbody Maintenance"
in Exterior Care 0374.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13690468) - 2021 - crc - 8/14/20
416 Connected Services
PressQ, then ask the Advisor to download
directions to the vehicle’s navigation system,
if equipped. After the call ends, the
navigation screen will provide prompts to
begin driving directions. Routes that are sent
to the navigation screen can only be
canceled through the navigation system.
See www.onstar.com (U.S.) or www.onstar.ca
(Canada).
Connections
The following services help with staying
connected.
For coverage maps, see www.onstar.com
(U.S.) or www.onstar.ca (Canada).
Ensuring Security
.Change the default passwords for the
Wi-Fi hotspot and myGMC mobile
application. Make these passwords
different from each other and use a
combination of letters and numbers to
increase the security.
.Change the default name of the SSID
(Service Set Identifier). This is your
network’s name that is visible to other
wireless devices. Choose a unique name
and avoid family names or vehicle
descriptions. Wi-Fi Hotspot (If Equipped)
The vehicle may have a built-in Wi-Fi
hotspot that provides access to the Internet
and web content at 4G LTE speed. Up to
seven mobile devices can be connected.
A data plan is required. Use the in-vehicle
controls only when it is safe to do so.
1. To retrieve Wi-Fi hotspot information, press
=to open the OnStar app on the
infotainment display, then select Wi-Fi
Hotspot. On some vehicles, touch Wi-Fi
or Wi-Fi Settings on the screen.
2. The Wi-Fi settings will display the Wi-Fi hotspot name (SSID), password, and on
some vehicles, the connection type (no
Internet connection, 3G, 4G, 4G LTE), and
signal quality (poor, good, excellent). The
LTE icon shows connection to Wi-Fi. It is
possible that the icon may not illuminate
even though the vehicle has an active
connection.
3. To change the SSID or password, press
Qor call 1-888-4ONSTAR to connect
with an Advisor. On some vehicles, the
SSID and password can be changed in
the Wi-Fi Hotspot menu. After initial set-up, your vehicle’s Wi-Fi
hotspot will connect automatically to your
mobile devices. Manage data usage by
turning Wi-Fi on or off on your mobile
device, using the myGMC mobile app, or by
contacting an OnStar Advisor. On some
vehicles, Wi-Fi can also be managed from
the Wi-Fi Hotspot menu.
MyGMC Mobile App (If Available)
Download the myGMC mobile app to
compatible Apple and Android smartphones.
GMC users can access the following services
from a smartphone:
.Remotely start/stop the vehicle,
if factory-equipped.
.Lock/unlock doors, if equipped with
automatic locks.
.Activate the horn and lamps.
.Check the vehicle’s fuel level, oil life,
or tire pressure, if factory-equipped with
the Tire Pressure Monitor System.
.Send destinations to the vehicle.
.Locate the vehicle on a map (U.S.
market only).
.Turn the vehicle's Wi-Fi hotspot on/off,
manage settings, and monitor data
consumption, if equipped.
.Locate a dealer and schedule service.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13690468) - 2021 - crc - 8/14/20
422 Index
Front Fog LampLight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Front Seats Heated and Ventilated . . . . . . . . . . . . . . . . . . 44
Fuel
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Dynamic Management . . . . . . . . . . . . . . . . . 231
Economy, Driving for Better . . . . . . . . . . . 213
Filling a Portable Fuel Container . . . . . . . 279
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . 278
Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 278
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Low Fuel Warning Light . . . . . . . . . . . . . . . . 118
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 277
Recommended . . . . . . . . . . . . . . . . . . . . . . . . . 277
Top Tier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . . . . 366
Fuses Engine Compartment Fuse Block . . . . . . . 332
Fuses and Circuit Breakers . . . . . . . . . . . . . 331
Instrument Panel Fuse Block . . . . . . . . . . . 335
Rear Compartment Fuse Block . . . . . . . . . 337
G
Garage Door Opener . . . . . . . . . . . . . . . . . . . . . . 131 Garage Door Opener (cont'd)
Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Gauges Engine Coolant Temperature . . . . . . . . . . . 108
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . 107
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 106
Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Warning Lights and Indicators . . . . . . . . . 103
General Information Service and Maintenance . . . . . . . . . . . . . . 383
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Glass Replacement . . . . . . . . . . . . . . . . . . . . . . . 330
Global Positioning System (GPS) . . . . . . . . . .174
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
Guidance Problems with the Route . . . . . . . . . . . . . . . 175
H
Hazard Warning Flashers . . . . . . . . . . . . . . . . . 137
HD Radio Technology . . . . . . . . . . . . . . . . . . . . 149
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Head-up Display . . . . . . . . . . . . . . . . . . . . . . . . . . 122
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Daytime Running Lamps (DRL) . . . . . . . . . 136
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
High-Beam On Light . . . . . . . . . . . . . . . . . . . . 119
High/Low Beam Changer . . . . . . . . . . . . . . 136
Lamps On Reminder . . . . . . . . . . . . . . . . . . . . 119
Heated
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 96
Heated and Ventilated Front Seats . . . . . . . 44
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 207
High-Beam On Light . . . . . . . . . . . . . . . . . . . . . . 119
High-Speed Operation . . . . . . . . . . . . . . . . . . . 345
Hill and Mountain Roads . . . . . . . . . . . . . . . . 220
Hill Descent Control (HDC) . . . . . . . . . . . . . . . 244
Hill Descent Control Light . . . . . . . . . . . . . . . . . 114
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 242
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
How to Wear Seat Belts Properly . . . . . . . . . 54