ECU GMC SIERRA 2018 Service Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 119
If the vehicle does not have a rear
seat that will accommodate a
rear-facing child restraint, a
rear-facing child restraint should not
be installed in the vehicle, even if
the airbag is off.
If a child restraint uses a top tether,
seeLower Anchors and Tethers for
Children (LATCH System) 099 for
top tether anchor locations.
Do not secure a child restraint in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top strap
must be anchored.
In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.
When using the lap-shoulder belt to
secure the child restraint in this
position, follow the instructions that
came with the child restraint and the
following instructions: 1. Move the seat as far back as it
will go before securing the
forward-facing child restraint.
Move the seat upward or the
seatback to an upright position,
if needed, to get a tight
installation of the child
restraint.
When the airbag off switch (if
equipped) has turned off the
front outboard passenger
frontal airbag, the off indicator
in the airbag off light should
light and stay lit when you start
the vehicle. See Airbag On-Off
Light 0147.
2. Put the child restraint on the seat.
3. Pick up the latch plate, and run the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how.
Tilt the latch plate to adjust the
belt, if needed.
4. Push the latch plate into the
buckle until it clicks.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
120 Seats and Restraints
Position the release button on
the buckle, away from the child
restraint system, so that the
seat belt could be quickly
unbuckled if necessary.
5. Pull the shoulder belt all theway out of the retractor to set
the lock. When the retractor
lock is set, the belt can be
tightened but not pulled out of
the retractor.
6. To tighten the belt, push downon the child restraint, pull the
shoulder portion of the belt to
tighten the lap portion of the
belt, and feed the shoulder belt
back into the retractor. When
installing a forward-facing child
restraint, it may be helpful to
use your knee to push down on
the child restraint as you
tighten the belt.
Try to pull the belt out of the
retractor to make sure the
retractor is locked. If the
retractor is not locked, repeat
Steps 5 and 6. 7. If the vehicle does not have a
rear seat and the child restraint
manufacturer recommends
using a top tether anchor,
attach the top tether to the top
tether anchor. Refer to the
instructions that came with the
child restraint and to Lower
Anchors and Tethers for
Children (LATCH System) 099.
8. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.
If you turned the airbag off with the
switch (if equipped), turn on the
front outboard passenger airbag

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 121
when you remove the child restraint
from the vehicle unless the person
who will be sitting there is a member
of a passenger airbag risk group.
SeeAirbag On-Off Switch 084 for
more information, including
important safety information.
Heavy-Duty Crew Cab Only
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint 098.
Never put a rear-facing child
restraint in the front. This is because
the risk to the rear-facing child is so
great if the airbag deploys.
{Warning
A child in a rear-facing child
restraint can be seriously injured
or killed if the passenger airbag
inflates. This is because the back
of the rear-facing child restraint
would be very close to the (Continued)
Warning (Continued)
inflating airbag. Secure
rear-facing child restraints in a
rear seat.
A child in a forward-facing child
restraint can be seriously injured
or killed if the front outboard
passenger airbag inflates and the
passenger seat is in a forward
position. If you secure a
forward-facing child restraint in
the front outboard passenger
seat, always move the seat as far
back as it will go. It is better to
secure the child restraint in a
rear seat.
If a child restraint uses a top tether,
see Lower Anchors and Tethers for
Children (LATCH System) 099 for
top tether anchor locations.
Do not secure a child restraint in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if the instructions that come with the
child restraint say that the top strap
must be anchored.
In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.
When using the lap-shoulder belt to
secure the child restraint in this
position, follow the instructions that
came with the child restraint and the
following instructions:
1. Move the seat as far back as it will go before securing the
forward-facing child restraint.
Move the seat upward or the
seatback to an upright position,
if needed, to get a tight
installation of the child
restraint.
2. Put the child restraint on the seat.
3. Pick up the latch plate, and run the lap and shoulder portions
of the vehicle's seat belt
through or around the restraint.
The child restraint instructions
will show you how.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Seats and Restraints 123
7. If your child restraint has a toptether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) 099 for more
information on using the top
tether anchors.
8. Before placing a child in the child restraint, make sure it is
securely held in place. To
check, grasp the child restraint
at the seat belt path and
attempt to move it side to side
and back and forth. When the
child restraint is properly
installed, there should be no
more than 2.5 cm (1 in) of
movement.
To remove the child restraint,
unbuckle the vehicle seat belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
128 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . 129
Steering Wheel Controls . . . . . . 129
Heated Steering Wheel . . . . . . . 130
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Windshield Wiper/Washer . . . . 130
Compass . . . . . . . . . . . . . . . . . . . . . 131
Clock . . . . . . . . . . . . . . . . . . . . . . . . . 132
Power Outlets . . . . . . . . . . . . . . . . 133
Wireless Charging . . . . . . . . . . . . 134
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . 137
Instrument Cluster . . . . . . . . . . . . 138
Speedometer . . . . . . . . . . . . . . . . . 142
Odometer . . . . . . . . . . . . . . . . . . . . . 142
Trip Odometer . . . . . . . . . . . . . . . . 142
Tachometer . . . . . . . . . . . . . . . . . . . 142
Fuel Gauge . . . . . . . . . . . . . . . . . . . 142
Engine Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . 143
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 144 Transmission Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 145
Voltmeter Gauge . . . . . . . . . . . . . 145
Seat Belt Reminders . . . . . . . . . 146
Airbag Readiness Light . . . . . . . 147
Airbag On-Off Light . . . . . . . . . . . 147
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . 149
Charging System Light . . . . . . . 149
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . 150
Brake System Warning Light . . . . . . . . . . . . . . . . . . . . . . . . 152
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . 152
Four-Wheel-Drive Light . . . . . . . 153
Tow/Haul Mode Light . . . . . . . . . 153
Hill Descent Control Light . . . . 153
Lane Departure Warning (LDW) Light (2500/3500) . . . . 153
Lane Keep Assist (LKA) Light (1500 Series) . . . . . . . . . . . . . . . 154
Vehicle Ahead Indicator . . . . . . 154
Traction Off Light . . . . . . . . . . . . . 154
StabiliTrak OFF Light . . . . . . . . . 154
Traction Control System (TCS)/ StabiliTrak Light . . . . . . . . . . . . . 155
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . 155
Tire Pressure Light . . . . . . . . . . . 156 Engine Oil Pressure Light
(Denali Only) . . . . . . . . . . . . . . . . 156
Low Fuel Warning Light . . . . . . 156
Security Light . . . . . . . . . . . . . . . . . 157
High-Beam On Light . . . . . . . . . . 157
Front Fog Lamp Light . . . . . . . . . 157
Lamps On Reminder . . . . . . . . . 157
Cruise Control Light . . . . . . . . . . 158
Door Ajar Light . . . . . . . . . . . . . . . 158
Information Displays
Driver Information Center (DIC) (Base Level Cluster) . . . . . . . . 158
Driver Information Center (DIC) (Uplevel and Denali
Cluster) . . . . . . . . . . . . . . . . . . . . . 160
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . 164
Engine Power Messages . . . . . 164
Vehicle Speed Messages . . . . . 164
Vehicle Personalization
Vehicle Personalization . . . . . . . 165
Universal Remote System
Universal Remote System . . . . 172
Universal Remote SystemProgramming . . . . . . . . . . . . . . . 172
Universal Remote System Operation . . . . . . . . . . . . . . . . . . . 174

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Instruments and Controls 157
It also comes on when the fuel tank
is low on fuel. The light turns off
when fuel is added. If it does not,
have the vehicle serviced.
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle
serviced by your dealer. If the
system is working normally, the
indicator light turns off.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. SeeImmobilizer Operation
0 46.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer 0179.
IntelliBeam®Light
This light comes on when the
IntelliBeam system, if equipped, is
enabled.
See Exterior Lamp Controls 0176.
Front Fog Lamp Light
For vehicles with fog lamps, this
light comes on when the fog lamps
are on.
The light goes out when the fog
lamps are turned off. See Fog
Lamps 0181.
Lamps On Reminder
This light comes on when the
exterior lamps are in use. See
Exterior Lamp Controls 0176.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
158 Instruments and Controls
Cruise Control Light
For vehicles with cruise control, the
cruise control light is white when the
cruise control is on and ready, and
turns green when the cruise control
is set and active.
The light turns off when the cruise
control is turned off. SeeCruise
Control 0285.
Door Ajar Light
This light comes on when a door is
open or not securely latched. Before
driving, check that all doors are
properly closed.
Information Displays
Driver Information Center
(DIC) (Base Level Cluster)
The DIC displays are shown in the
center of the instrument cluster. The
displays show the status of many
vehicle systems. The trip odometer
reset stem in the instrument cluster
is used to access the DIC menu
items.
DIC Menu Items
Turn the trip odometer reset stem to
scroll through the following menu
items:
.
Digital Speedometer
. Trip
. Fuel Range
. Average Fuel Economy
. Tire Pressure
. Remaining Oil Life
. Transmission Fluid Temperature
. Trailer Brake
. Hourmeter

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
164 Instruments and Controls
Vehicle Messages
Messages displayed on the DIC
indicate the status of the vehicle or
some action that may be needed to
correct a condition. Multiple
messages may appear one after
another.
The messages that do not require
immediate action can be
acknowledged and cleared by
pressing
V. The messages that
require immediate action cannot be
cleared until that action is
performed.
All messages should be taken
seriously; clearing the message
does not correct the problem.
If a SERVICE message appears,
see your dealer.
Follow the instructions given in the
messages. The system displays
messages regarding the following
topics:
. Service Messages
. Fluid Levels
. Vehicle Security .
Brakes
. Ride Control Systems
. Driver Assistance Systems
. Cruise Control
. Lighting and Bulb Replacement
. Wiper/Washer Systems
. Doors and Windows
. Seat Belts
. Airbag Systems
. Engine and Transmission
. Tire Pressure
. Battery
Engine Power Messages
ENGINE POWER IS REDUCED
This message displays when the
vehicle's propulsion power is
reduced. Reduced propulsion power
can affect the vehicle's ability to
accelerate. If this message is on,
but there is no observed reduction
in performance, proceed to your
destination. The performance may
be reduced the next time the vehicle is driven. The vehicle may be driven
while this message is on, but
maximum acceleration and speed
may be reduced. Anytime this
message stays on, or displays
repeatedly, the vehicle should be
taken to your dealer for service as
soon as possible.
Vehicle Speed Messages
SPEED LIMITED TO
XXX KM/H (MPH)
This message shows that the
vehicle speed has been limited to
the speed displayed. The limited
speed is a protection for various
propulsion and vehicle systems,
such as lubrication, thermal,
suspension, Teen Driver if
equipped, or tires.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
172 Instruments and Controls
Restore Radio Settings
This allows selection to restore
radio settings.
Select Restore or Cancel.
Software Information
Select to view the infotainment
system current software information.
Wi-Fi
Select and the following may
display:
.Wi-Fi
. Manage Wi-Fi Networks
Wi-Fi
This feature allows Wi-Fi networks
to be turned off or on.
Select Off or On.
Manage Wi-Fi Networks
Select to manage Wi-Fi networks.
Wi-Fi must be on for this feature to
be accessed.
Universal Remote
System
See Radio Frequency Statement
0 475.
Universal Remote System
Programming
If equipped, these buttons are in the
overhead console.
This system can replace up to three
remote control transmitters used to
activate devices such as garage
door openers, security systems, and
home automation devices. These instructions refer to a garage door
opener, but can be used for other
devices.
Do not use the Universal Remote
system with any garage door opener
that does not have the stop and
reverse feature. This includes any
garage door opener model
manufactured before April 1, 1982.
Read the instructions completely
before programming the Universal
Remote system. It may help to have
another person assist with the
programming process.
Keep the original hand-held
transmitter for use in other vehicles
as well as for future programming.
Erase the programming when
vehicle ownership is terminated.
See
“Erasing Universal Remote
System Buttons” later in this
section.
To program a garage door opener,
park outside directly in line with and
facing the garage door opener
receiver. Clear all people and
objects near the garage door.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
190 Infotainment System
To manually check for updates,
touch SETTINGS on the Home
Page, followed by Software
Information, and then System
Update. Follow the on-screen
prompts. Steps for downloading and
installing updates may vary by
vehicle.
Downloading Over-the-Air vehicle
software updates requires Internet
connectivity, which can be accessed
through the vehicle’s built-in OnStar
4G LTE connection, if equipped and
active. If required, data plans are
provided by a third party. Optionally,
a secure Wi-Fi hotspot such as a
compatible mobile device hotspot,
home hotspot or public hotspot can
be used. Applicable data rates may
apply. To connect the infotainment system
to a secured mobile device hotspot,
home hotspot, or a public hotspot,
touch SETTINGS on the Home
Page, followed by Wi-Fi, and then
Manage Wi-Fi Networks. Select the
appropriate Wi-Fi network, and
follow the on-screen prompts.
Download speeds may vary.
On most compatible mobile devices,
activation of the Wi-Fi hotspot is in
the Settings menu under Mobile
Network Sharing, Personal Hotspot,
Mobile Hotspot or similar.
Availability of Over-the-Air vehicle
software updates varies by vehicle
and country. For more information
on this feature, see my.gmc.com/
learn.Radio
AM-FM Radio
Playing the Radio
Audio Source Menu
{:
Press to go to the Home Page.
O:Press to turn on, mute,
or unmute the system. Press and
hold to turn off the system.
Selecting a Band
Press{, then touch AUDIO,
Source, then select AM, FM,
or SXM, if equipped. The last station
that was playing starts playing
again.
System Settings
Auto Volume
This feature automatically adjusts
the radio volume to compensate for
road and wind noise.
The level of volume compensation
can be selected, or the feature can
be turned off.