2020 GMC SIERRA DENALI maintenance

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
444 Service and Maintenance
Additional Required ServicesMaintenance Schedule
Additional Required
Services - Normal
12 000 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. Check
engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
If the vehicle is not equipped with the engine air
filter life system, replace engine air cleaner
filter. (2)@ @@
Inspect evaporative control system. (3)@@@
Replace spark plugs. Inspect spark plug wires.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires.
(2.7L L4 Turbo Engine Only)@ @
For GVW under 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@
For GVW over 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Service and Maintenance 445
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
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate
dampener. (9)@ @
Replace air conditioning desiccant. (10)
Footnotes—Maintenance
Schedule Additional Required
Services - Normal
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter
replacement may also be needed if
you notice reduced airflow, windows
fogging up, or odors. Your local GM Service location can help you
determine when it is the right time to
replace your filter.
(2)
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 0344.
(3) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition. (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 fluid. Contaminated
fluid will decrease the life of the
transfer case and/or drive axles and
should be replaced.
(5) Or every five years, whichever
comes first. See Cooling System
0 346.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
446 Service and Maintenance
(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 0357.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0364.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0365.
(10) Replace air conditioning
desiccant every seven years.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Service and Maintenance 447
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. Check
engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
If the vehicle is not equipped with the engine air
filter life system, replace engine air cleaner
filter. (2)@ @@
Inspect evaporative control system. (3)@@@
Replace spark plugs. Inspect spark plug wires.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires.
(2.7L L4 Turbo Engine Only)@ @
Change automatic transmission fluid and filter.@@@
For GVW under 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@@@
For GVW over 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@@@@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate
dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
448 Service and Maintenance
Footnotes—Maintenance
Schedule Additional Required
Services - Severe
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter
replacement may also be needed if
you notice reduced airflow, windows
fogging up, or odors. Your local GM
Service location can help you
determine when it is the right time to
replace your filter.
(2) 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 0344.
(3) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition. (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 fluid. Contaminated
fluid will decrease the life of the
transfer case and/or drive axles and
should be replaced.
(5) Or every five years, whichever
comes first. See Cooling System
0 346.
(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 0357.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0364.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0365.
(10) Replace air conditioning
desiccant every seven years.Special Application
Services
. Vehicles with Dual Wheels:
Check dual wheel nut torque at
160, 1 600, and 10 000 km (100,
1,000, and 6,000 mi) of driving.
Repeat this service whenever a
tire/wheel is serviced or
removed.
. Severe Commercial Use
Vehicles Only: Lubricate chassis
components every oil change.
. Have underbody flushing service
performed. See “Underbody
Maintenance” inExterior Care
0 429.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Service and Maintenance 449
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 0452 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 Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
450 Service and Maintenance
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
. With a multi-point inspection,
your dealer can check the lamps
and note any concerns.
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
. Signs of wear may include
steering wheel vibration, bounce/
sway while braking, longer
stopping distance, or uneven
tire wear.
. As part of the multi-point
inspection, trained dealer
technicians can visually inspect
the shocks and struts for signs of leaking, blown seals,
or damage, and can advise
when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money and fuel,
and can reduce the risk of tire
failure.
. Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord
or fabric showing through the
rubber; cracks or cuts in the
tread or sidewall; or a bulge or
split in the tire.
. Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also
provide tire/wheel balancing
services to ensure smooth
vehicle operation at all speeds.
Your dealer sells and services
name brand tires. Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle’s interior and
exterior, see
Interior Care 0435 and
Exterior Care 0429.
Wheel Alignment
Wheel alignment is critical for
ensuring that the tires deliver
optimal wear and performance.
. Signs that the alignment may
need to be adjusted include
pulling, improper vehicle
handling, or unusual tire wear.
. Your dealer has the required
equipment to ensure proper
wheel alignment.
Windshield
For safety, appearance, and the
best viewing, keep the windshield
clean and clear.
. Signs of damage include
scratches, cracks, and chips.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Service and Maintenance 451
.Trained dealer technicians can
inspect the windshield and
recommend proper replacement
if needed.
Wiper Blades
Wiper blades need to be cleaned
and kept in good condition to
provide a clear view.
. Signs of wear include streaking,
skipping across the windshield,
and worn or split rubber.
. Trained dealer technicians can
check the wiper blades and
replace them when needed.