2018 GMC SIERRA Maintenance

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . 2
In Brief . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Keys, Doors, and Windows . . . . . 34
Seats and Restraints . . . . . . . . . . . 57
Storage . . . . . . . . . . . . . . . . . . . . . . . 124
Instruments and Controls . . . . . . 128
Lighting . . . . . . . . . . . . . . . . . . . . . . . 176
Infotainment System . . . . . . . . . . 186
Climate Controls . . . . . . . . . . . . . . 224
Driving and Operating . . . . . . . . . 234
Vehicle Care . . . . . . . . . . . . . . . . . . 341
Service and Maintenance . . . . . 446
Technical Data . . . . . . . . . . . . . . . . 460
Customer Information . . . . . . . . . 465
Reporting Safety Defects . . . . . . 476
OnStar . . . . . . . . . . . . . . . . . . . . . . . . 479
Index . . . . . . . . . . . . . . . . . . . . 491

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
In Brief 5
In Brief
Instrument Panel
Instrument Panel . . . . . . . . . . . . . . . . 6
Initial Drive Information
Initial Drive Information . . . . . . . . . . 8
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . . 8
Remote Vehicle Start . . . . . . . . . . . 9
Door Locks . . . . . . . . . . . . . . . . . . . . . 9
Windows . . . . . . . . . . . . . . . . . . . . . . . 10
Seat Adjustment . . . . . . . . . . . . . . . 11
Memory Features . . . . . . . . . . . . . . 13
Heated and Ventilated Seats . . . 13
Head Restraint Adjustment . . . . 14
Seat Belts . . . . . . . . . . . . . . . . . . . . . 14
Passenger Sensing System . . . 14
Mirror Adjustment . . . . . . . . . . . . . . 15
Steering Wheel Adjustment . . . . 16
Throttle and Brake Pedal Adjustment . . . . . . . . . . . . . . . . . . . 17
Interior Lighting . . . . . . . . . . . . . . . . 17
Exterior Lighting . . . . . . . . . . . . . . . 18
Windshield Wiper/Washer . . . . . . 19
Climate Controls . . . . . . . . . . . . . . . 20
Transmission . . . . . . . . . . . . . . . . . . 22
Four-Wheel Drive . . . . . . . . . . . . . . 23
Vehicle Features
Infotainment System . . . . . . . . . . . 24
Radio(s) . . . . . . . . . . . . . . . . . . . . . . . 24
Satellite Radio . . . . . . . . . . . . . . . . . 25
Portable Audio Devices . . . . . . . . 25
Bluetooth . . . . . . . . . . . . . . . . . . . . . . 25
Steering Wheel Controls . . . . . . . 26
Cruise Control . . . . . . . . . . . . . . . . . 26
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . 27
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . 27
Forward Automatic Braking (FAB) . . . . . . . . . . . . . . . . 27
Lane Departure Warning (LDW) . . . . . . . . . . . . . . . 28
Lane Keep Assist (LKA) . . . . . . . 28
Rear Vision Camera (RVC) . . . . 28
Parking Assist . . . . . . . . . . . . . . . . . 28
Power Outlets . . . . . . . . . . . . . . . . . 28
Universal Remote System . . . . . 29
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 29
Performance and Maintenance
Traction Control/Electronic Stability Control . . . . . . . . . . . . . . 30
Tire Pressure Monitor . . . . . . . . . . 31
Fuel (Gasoline - Except L86 6.2L Engine) . . . . . . . . . . . . . 31 Fuel (Gasoline - L86 6.2L
Engine) . . . . . . . . . . . . . . . . . . . . . . . 32
Fuel (Diesel) . . . . . . . . . . . . . . . . . . . 32
E85 or FlexFuel . . . . . . . . . . . . . . . . 32
Engine Oil Life System . . . . . . . . 32
Driving for Better Fuel Economy . . . . . . . . . . . . . . . . . . . . . 33
Roadside Assistance Program . . . . . . . . . . . . . . . . . . . . . . 33

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
30 In Brief
To express-close the sunroof, fully
press and release
K. Press the
switch again to stop the movement.
Open/Close (Manual Mode) : To
open the sunroof, press and hold
I. Release the switch to stop the
movement. Press and hold
Kto
close the sunroof. Release the
switch to stop the movement.
Tilt Switch
Vent : From the closed position,
press
Jto vent the sunroof. Press
Kto close the vent. When the sunroof is opened, an air
deflector will automatically raise.
The air deflector will retract when
the sunroof is closed.
The sunroof also has a sunshade,
which can be pulled forward to block
sun rays. The sunshade must be
opened and closed manually.
If an object is in the path of the
sunroof while it is closing, the
automatic reversal system will
detect the object and stop the
sunroof.
See
Sunroof 055.
Performance and
Maintenance
Traction Control/
Electronic Stability
Control
The vehicle has a Traction Control
System (TCS) that limits wheel spin
and the StabiliTrak system that
assists with directional control of the
vehicle in difficult driving conditions.
Both systems come on
automatically when the vehicle is
started and begins to move.
.
To turn off TCS, press and
release
gon the center stack.
The traction off light
idisplays
in the instrument cluster. The
appropriate Driver Information
Center (DIC) message displays.
. To turn off both TCS and
StabiliTrak, press and hold
g
untiliandgilluminate in the
instrument cluster and the
appropriate DIC message
displays.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
In Brief 31
.Press and releasegagain to
turn on both systems.
StabiliTrak will automatically turn on
if the vehicle exceeds 56 km/h
(35 mph). Traction control will
remain off.
See Traction Control/Electronic
Stability Control 0282.
Tire Pressure Monitor
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The low tire pressure warning light
alerts to a significant loss in
pressure of one of the vehicle's
tires. If the warning light comes on,
stop as soon as possible and inflate
the tires to the recommended
pressure shown on the Tire and Loading Information label. See
Vehicle Load Limits
0248. The
warning light will remain on until the
tire pressure is corrected.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
may be an early indicator that the
tire pressures are getting low and
the tires need to be inflated to the
proper pressure.
The TPMS does not replace normal
monthly tire maintenance. Maintain
the correct tire pressures.
See Tire Pressure Monitor System
0 399.
Tire Fill Alert (If Equipped)
This feature provides visual and
audible alerts outside the vehicle to
help when inflating an underinflated
tire to the recommended cold tire
pressure. See “Tire Fill Alert (If
Equipped)” underTire Pressure
Monitor Operation 0400.
Fuel (Gasoline - Except
L86 6.2L Engine)
Regular Fuel
Use only unleaded gasoline rated
87 octane or higher in your vehicle.
Do not use gasoline with an octane
rating lower as it may result in
vehicle damage and lower fuel
economy. See Fuel0299.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
In Brief 33
2. Fully press the acceleratorpedal slowly three times within
five seconds.
3. If the display changes to 100%, the system is reset.
See Engine Oil Life System 0353.
Driving for Better Fuel
Economy
Driving habits can affect fuel
mileage. Here are some driving tips
to get the best fuel economy
possible.
.
Avoid fast starts and accelerate
smoothly.
. Brake gradually and avoid
abrupt stops.
. Avoid idling the engine for long
periods of time.
. When road and weather
conditions are appropriate, use
cruise control.
. Always follow posted speed
limits or drive more slowly when
conditions require. .
Keep vehicle tires properly
inflated.
. Combine several trips into a
single trip.
. Replace the vehicle's tires with
the same TPC Spec number
molded into the tire's sidewall
near the size.
. Follow recommended scheduled
maintenance.
Roadside Assistance
Program
U.S.: 1-888-881-3302
TTY Users (U.S. Only):
1-888-889-2438
Canada: 1-800-268-6800
New GMC owners are automatically
enrolled in the Roadside Assistance
Program.
See Roadside Assistance Program
0 469.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 91
trim, overhead console, front
sensors, side impact sensors,
or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
In addition, the vehicle may have a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger’s seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with
GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly turning off the passenger airbag(s).
See
Passenger Sensing System
0 86.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0409 for additional
important information.
If a snow plow is added to the
vehicle, the airbags should still work
properly. The airbag systems were
designed to work properly under a
wide range of conditions, including
snow plowing with vehicles that
have the optional snow plow prep
package (RPO VYU). Do not
change or defeat the snow plow's
“tripping mechanism.” If you do, it
can damage the snow plow and the
vehicle, and may cause an airbag
deployment.
If you have to modify your vehicle
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other reason, call Customer Assistance.
See
Customer Assistance Offices
0 467.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light 0147.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag
may not work properly. Do not
open or break the airbag
coverings. If there are any
opened or broken airbag
coverings, have the airbag
covering and/or airbag module
replaced. For the location of the
airbags, see Where Are the
Airbags? 078. See your dealer
for service.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
144 Instruments and Controls
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check
the oil level as soon as possible.
Add oil if required, but if the oil
level is within the operating range
and the oil pressure is still low,
have the vehicle serviced. Always
follow the maintenance schedule
for changing engine oil.
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
Engine Coolant
Temperature Gauge
Metric, Standard Theme Shown
English, Standard Theme Shown
This gauge shows the engine
coolant temperature. Under normal
driving conditions the gauge will
read approximately 100 °C (210 °F)
or less. If the gauge pointer is near
125 °C (260 °F), the engine is
too hot.
It means that the engine coolant has
overheated. If the vehicle has been
operating under normal driving
conditions, pull off the road, stop the
vehicle, and turn off the engine as
soon as possible.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
150 Instruments and Controls
system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction Indicator
Lamp (Check Engine
Light)
This light is part of the vehicle’s
emission control on-board
diagnostic system. If this light is on
while the engine is running, a
malfunction has been detected and
the vehicle may require service. The
light should come on to show that it
is working when the ignition is on
and the engine is not running. See
Ignition Positions0256.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when
it comes on may prevent damage.
Caution
If the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not
run smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty.
Caution
Modifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not
meet the original tire
specifications, can cause this light
to come on. This could lead to
costly repairs not covered by the
vehicle warranty. This could also
affect the vehicle’s ability to pass
an Emissions Inspection/
Maintenance test. See
Accessories and Modifications
0343.
If the light is flashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service
may be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.