check engine GMC YUKON 2020 Service Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
378 Service and Maintenance
The Tire Rotation and Required
Services are the responsibility of the
vehicle owner. It is recommended to
have your dealer perform these
services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to
keep the vehicle in good working
condition, improves fuel economy,
and reduces vehicle emissions.
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more
frequent checks and services. The
Additional Required Services -
Normal are for vehicles that:
.Carry passengers and cargo
within recommended limits on
the Tire and Loading Information
label. See Vehicle Load Limits
0 196.
. Are driven on reasonable road
surfaces within legal driving
limits. .
Use the recommended fuel. See
Recommended Fuel (L83 5.3L
V8 Engine) 0254 or
Recommended Fuel (L86 6.2L
V8 Engine) 0254.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Normal chart.
The Additional Required Services -
Severe are for vehicles that are:
. Mainly driven in heavy city traffic
in hot weather.
. Mainly driven in hilly or
mountainous terrain.
. Frequently towing a trailer.
. Used for high speed or
competitive driving.
. Used for taxi, police, or delivery
service.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Severe chart.{Warning
Performing maintenance work can
be dangerous and can cause
serious injury. Perform
maintenance work only if the
required information, proper tools,
and equipment are available.
If they are not, see your dealer to
have a trained technician do the
work. See Doing Your Own
Service Work 0283.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Service and Maintenance 379
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil 0289.
Once a Month
. Check the tire inflation
pressures, including the spare.
See Tire Pressure 0333.
. Inspect the tires for wear. See
Tire Inspection 0340.
. Check the windshield washer
fluid level. See Washer Fluid
0 302.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system may not
indicate the need for vehicle service
for up to a year. The engine oil and filter must be changed at least once
a year and the oil life system must
be reset. Your trained dealer
technician can perform this work.
If the engine oil life system is reset
accidentally, service the vehicle
within 5 000 km/3,000 mi since the
last service. Reset the oil life
system when the oil is changed.
See
Engine Oil Life System 0291.
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)
0144 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 0340.
. Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil 0289 and
Engine Oil Life System 0291.
. Check engine coolant level. See
Cooling System 0297.
. Check windshield washer fluid
level. See Washer Fluid 0302.
. Check tire inflation pressures,
including the spare. See Tire
Pressure 0333.
. Inspect tire wear. See Tire
Inspection 0340.
. Visually check for fluid leaks.
. Inspect engine air cleaner filter.
See Engine Air Cleaner/Filter
0 296.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Service and Maintenance 381
Maintenance Schedule
Additional Required
Services - Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
Inspect evaporative control system. (2)@ @@
Replace engine air cleaner filter. (3)@@@
Change transfer case fluid, if equipped with
4WD. (4)@
Replace spark plugs. Inspect spark plug wires.@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas
struts. (9)@ @
Replace air conditioning desiccant. (10)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
382 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 0296.
(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
0 297.
(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 0304.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0309.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0310.
(10) Replace air conditioning
desiccant every seven years.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Service and Maintenance 383
Maintenance Schedule
Additional Required
Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed.@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
Inspect evaporative control system. (2)@ @@
Replace engine air cleaner filter. (3)@@@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with
4WD. (4)@@@
Replace spark plugs. Inspect spark plug wires.@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas
struts. (9)@ @
Replace air conditioning desiccant. (10)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
384 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services - Severe
(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.
Engine Air Cleaner/Filter 0296.
(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
0 297.
(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 0304.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0309.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0310.
(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
0 367.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Service and Maintenance 385
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 0388 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
394 Technical Data
ApplicationCapacities
Metric English
Wheel Nut Torque 190 Y140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck fluid level after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
5.3L V8 C0.95–1.10mm (0.037–
0.043 in)
6.2L V8 J0.95–1.10mm (0.037–
0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage
the spark plug.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Customer Information 405
original GM parts. Remember,
recycled parts will not be covered by
the GM vehicle warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits,
your insurance company may
initially value the repair using
aftermarket parts. Discuss this with
the repair professional, and insist on
Genuine GM parts. Remember,
if the vehicle is leased, you may be
obligated to have the vehicle
repaired with Genuine GM parts,
even if your insurance coverage
does not pay the full cost.
If another party's insurance
company is paying for the repairs,
you are not obligated to accept a
repair valuation based on that
insurance company's collision policy
repair limits, as you have no
contractual limits with that company.
In such cases, you can have control
of the repair and parts choices as
long as the cost stays within
reasonable limits.Publication Ordering
Information
Service Manuals
Service manuals have the diagnosis
and repair information on the
engine, transmission, axle,
suspension, brakes, electrical
system, steering system, body, etc.
Customer Literature
Owner’s manuals are written
specifically for owners and are
intended to provide basic
operational information about the
vehicle. The owner ’s manual
includes the Maintenance Schedule
for all models.
Customer literature publications
available for purchase include
owner ’s manuals, warranty
manuals, infotainment manuals, and
portfolios. Portfolios include an
owner ’s manual, warranty manual,
infotainment manual, if applicable,
and zip lock bag or pouch.
Current and Past Models
Service manuals and customer
literature are available for many
current and past model year GM
vehicles.
To order, call 1-800-551-4123
Monday–Friday, 8:00 a.m.–6:00 p.m.
eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see
Helm, Inc. at: www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.
Radio Frequency
Statement
This vehicle has systems that
operate on a radio frequency that
complies with Part 15/Part 18 of the
Federal Communications
Commission (FCC) rules and with

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13566587) - 2020 - CRC - 4/15/19
Index 421
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 283
Accessory Power . . . . . . . . . . . . . . . 209
Active Fuel Management . . . . . . . 211
Adaptive Cruise Control . . . . . . . . 232
Add-On Electrical Equipment . . . 280
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . 412
Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . . . 385
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . . 201
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 49
Air Cleaner/Filter, Engine . . . . . . . 296
Air Conditioning . . . . . . . . . . . 175, 179
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 181
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 180
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 85
How Does an AirbagRestrain? . . . . . . . . . . . . . . . . . . . . . 78
Passenger Sensing System . . . . 80
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 78 Airbag System (cont'd)
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 78
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 77
Where Are the Airbags? . . . . . . . . 75
Airbags Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 84
Passenger Status Indicator . . . 135
Readiness Light . . . . . . . . . . . . . . 134
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 84
System Check . . . . . . . . . . . . . . . . . . 73
Alarm Vehicle Security . . . . . . . . . . . . . . . . 33
Alert Lane Change . . . . . . . . . . . . . . . . . 250
Side Blind Zone (SBZA) . . . . . . 249
All-Season Tires . . . . . . . . . . . . . . . . 327
All-Terrain Tires . . . . . . . . . . . . . . . . . 328
Antilock Brake System (ABS) . . . 224 Warning Light . . . . . . . . . . . . . . . . . 138
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 367
Interior . . . . . . . . . . . . . . . . . . . . . . . . 372
Armrest Storage . . . . . . . . . . . . . . . . 110