engine GMC SIERRA 2020 Owner's Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 423
6. Check that the jumper cablesdo not have loose or missing
insulation. If they do, you could
get a shock. The vehicles
could be damaged too.
Before you connect the cables,
here are some basic things you
should know. Positive (+) will
go to positive (+) or to a remote
positive (+) terminal if the
vehicle has one. Negative (−)
will go to a heavy, unpainted
metal engine part or to a
remote negative (−) terminal if
the vehicle has one.
Do not connect positive (+) to
negative (−) or you will get a
short that would damage the
battery and maybe other parts
too. And do not connect the
negative (−) cable to the
negative (−) terminal on the
dead battery because this can
cause sparks.
7. Connect one end of the red positive (+) cable to the remote
positive (+) terminal of the
vehicle with the discharged
battery. 8. Do not let the other end touch
metal. Connect it to the
positive (+) terminal of the
good battery. Use a remote
positive (+) terminal if the
vehicle has one.
9. Connect one end of the black negative (−) cable to the
negative (−) terminal of the
good battery. Use a remote
negative (−) terminal if the
vehicle has one.
Do not let the other end touch
anything until the next step.
10. Connect the other end of the negative (−) cable to the
remote negative (−) terminal to
the discharged battery.
11. Start the vehicle with the good battery and run the engine for a
while.
12. Try to start the vehicle that had the dead battery. If it will not
start after a few tries, it
probably needs service.Caution
If the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle
and removing the jumper cables,
allow it to idle for several minutes.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
426 Vehicle Care
Two-wheel-drive vehicles and
vehicles with a single-speed transfer
case should not be towed with all
four wheels on the ground.
Dinghy Towing (Vehicles with a
Two-Speed Transfer Case)
Only dinghy tow four-wheel-drive
vehicles with a two-speed transfer
case that have an N (Neutral) and a
4
n(Four-Wheel Drive Low) setting.
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can allow the vehicle
to move even if the transmission
is in P (Park). You or others could
be injured. Set the parking brake
and use wheel blocks before
shifting the transfer case to
N (Neutral).
To dinghy tow: 1. Position the vehicle being towed behind the tow vehicle,
facing forward and on a level
surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive 0227. 5. With the engine running,
release the parking brake and
verify that the transfer case is
in N (Neutral) by shifting the
transmission to D (Drive) and
then to R (Reverse). There
should be no movement while
shifting the transmission.
6. Shift the transmission to D (Drive).
7. If equipped with an ignition key, turn the ignition to ACC/
ACCESSORY. If equipped with
Keyless Access, turn the
engine off. Disregard the Shift
to P (Park) DIC message. See
Ignition Positions (Keyless
Access) 0208 or
Ignition Positions (Key Access)
0 210.
{Warning
To avoid death, serious injury,
or property damage, before
dinghy towing the vehicle, always
disconnect and secure the
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 427
Warning (Continued)
negative battery cable and cover
the negative battery post and
cable with a non-conductive
material. If the battery is left
connected or the battery cable
contacts the post, the Electric
Parking Brake may activate
during towing, which could cause
a crash.
8. Disconnect the negative (–) battery cable. See “Negative
Battery Cable Disconnection”
in Battery - North America
0 358.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked,
vehicle damage may occur.
10. Move the steering wheel to make sure the steering column
is unlocked.
11. If the vehicle has an ignition key, keep it in the towed
vehicle in ACC/ACCESSORY
to prevent the steering column
from locking. If the vehicle is
equipped with Keyless Access,
keep the RKE transmitter
outside of the vehicle and
manually lock the doors.
Access the vehicle by using
the key in the door lock. See
Door Locks 025.
Disconnecting the Towed Vehicle
Before disconnecting from the tow
vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks. 2. Re-connect the negative (–)
battery. See Battery - North
America 0358.
3. Turn on the ignition with the engine off. For vehicles with a
key, turn the ignition to ON/
RUN with the engine off. If the
vehicle is equipped with
Keyless Access, with your foot
off the brake pedal, press and
hold ENGINE START/STOP for
five seconds until the green
light comes on in the button.
See Ignition Positions (Keyless
Access) 0208 or
Ignition Positions (Key Access)
0 210.
4. Set the parking brake. See Electric Parking Brake 0233.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m
(Two-Wheel Drive High). When
the shift to 2
m(Two-Wheel
Drive High) is complete, the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
428 Vehicle Care
light in the instrument cluster
will stop flashing and stay lit.
SeeFour-Wheel-Drive Light
0 142.
8. Start the engine. Check that the vehicle is in 2
m
(Two-Wheel Drive High) by
starting the engine and shifting
the transmission to D (Drive)
and then to R (Reverse). There
should be movement of the
vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the
ignition.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets. The outside temperature
display will default to 0 °C (32 °
F) but will reset with normal
usage.
Dolly TowingCaution
Do not tow this vehicle with two
wheels on the ground, or vehicle
damage could occur. This
damage would not be covered by
the vehicle warranty.
Dolly towing this vehicle is not
allowed with either the front or the
rear tires on the ground for
two-wheel drive or four-wheel drive,
regardless of transfer case.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
434 Vehicle Care
Brake System
Visually inspect brake lines and
hoses for proper hook-up, binding,
leaks, cracks, chafing, etc. Inspect
disc brake pads for wear and rotors
for surface condition. Inspect drum
brake linings/shoes for wear or
cracks. Inspect all other brake parts.
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
attachment, connections, binding,
cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
2500/3500 Series vehicles, at least
every engine oil change lubricate
the upper and lower control arm ball
joints. Control arm ball joints on
1500 series vehicles are
maintenance-free.2500/3500 Series vehicles equipped
with steering linkage, at least every
engine oil change lubricate the tie
rod ball joints, idler arm pivot shaft
bearings, idler arm socket, and
pitman arm socket.
Caution
Lubrication of applicable
suspension points should not be
done unless the temperature is
−12 °C (10 °F) or higher,
or damage could result.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any
corrosive materials from the
underbody. Take care to thoroughly
clean any areas where mud and
other debris can collect. If equipped
with power assist steps, extend
them and then use a high pressure
wash to clean all joints and gaps.
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 axles and
should be replaced.
Sheet Metal Damage
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
440 Service and Maintenance
Service and
Maintenance
General Information
General Information . . . . . . . . . . 440
Maintenance Schedule
Maintenance Schedule . . . . . . . 442
Special Application Services
Special ApplicationServices . . . . . . . . . . . . . . . . . . . . 449
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . . 450
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . 453
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . 455
Maintenance Records
Maintenance Records . . . . . . . . 457
General Information
This maintenance section applies to
vehicles with a gasoline engine. For
diesel engine vehicles, see
"Maintenance Schedule" in the
Duramax diesel supplement.
Your vehicle is an important
investment. This section describes
the required maintenance for the
vehicle. Follow this schedule to help
protect against major repair
expenses resulting from neglect or
inadequate maintenance. It may
also help to maintain the value of
the vehicle if it is sold. It is the
responsibility of the owner to have
all required maintenance performed.
Your dealer has trained technicians
who can perform required
maintenance using genuine
replacement parts. They have
up-to-date tools and equipment for
fast and accurate diagnostics. Many
dealers have extended evening and
Saturday hours, courtesy
transportation, and online
scheduling to assist with service
needs. Your dealer recognizes the
importance of providing
competitively priced maintenance
and repair services. With trained
technicians, the dealer is the place
for routine maintenance such as oil
changes and tire rotations and
additional maintenance items like
tires, brakes, batteries, and wiper
blades.
Caution
Damage caused by improper
maintenance can lead to costly
repairs and may not be covered
by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids,
and lubricants are important to
keep the vehicle in good working
condition.
Do not have chemical flushes that
are not approved by GM
performed on the vehicle. The
use of flushes, solvents, cleaners,
or lubricants that are not
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Service and Maintenance 441
Caution (Continued)
approved by GM could damage
the vehicle, requiring expensive
repairs that are not covered by
the vehicle warranty.
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
0 200.
. Are driven on reasonable road
surfaces within legal driving
limits.
. Use the recommended fuel. See
Recommended Fuel (Except
6.2L V8 Engine) 0280 or
Recommended Fuel (6.2L
V8 Engine) 0281. 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
442 Service and Maintenance
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. SeeDoing Your Own
Service Work 0330.
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.
Check the engine oil level. See
Engine Oil 0339.
Once a Month
. Check the tire inflation
pressures, including the spare.
See Tire Pressure 0387.
. Inspect the tires for wear. See
Tire Inspection 0396.
. Check the windshield washer
fluid level. See Washer Fluid
0 354.
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 0341.
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 0343.
Passenger Compartment Air
Filter
The passenger compartment air
filter removes dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Service and Maintenance 443
The filter should be replaced as part
of routine scheduled maintenance.
Inspect the passenger compartment
air filter every 36 000 km/
22,500 miles or two years,
whichever comes first. Replace if
necessary. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, areas with poor air quality,
or areas with high dust levels.
Replacement may also be needed if
there is a reduction in air flow,
excessive window fogging, or odors.
Power Take Off (PTO) and
Extended Idle Use
When the vehicle is used with the
PTO equipment or 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)
(Base Level)0148 or
Driver Information Center (DIC)
(Midlevel and Uplevel) 0149 for
hourmeter, if equipped.
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 0396.
. Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil 0339 and
Engine Oil Life System 0341.
. 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 0343. If the
vehicle is not equipped with the
engine air filter life system,
inspect the engine air cleaner
filter. See Engine Air Cleaner/
Filter 0344.
. Check engine coolant level. See
Cooling System 0346.
. Check windshield washer fluid
level. See Washer Fluid 0354.
. Check tire inflation pressures,
including the spare. See Tire
Pressure 0387.
. Inspect tire wear. See Tire
Inspection 0396.
. Visually check for fluid leaks.
. Inspect brake system. See
Exterior Care 0429.
. 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 Care
0 429. If equipped with grease

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Service and Maintenance 445
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)@