2018 GMC YUKON XL ECU

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
In Brief 23
Universal Remote System
If equipped with the Universal
Remote system, these buttons will
be in the front overhead console.
This system provides a way to
replace up to three remote control
transmitters used to activate
devices such as garage door
openers, security systems, and
home automation devices.
See Universal Remote System
0 166 . Sunroof
1. SLIDE Switch
2. TILT Switch
If equipped, the sunroof only
operates when the ignition is on or
in ACC/ACCESSORY, or when
Retained Accessory Power (RAP) is
active. See Retained Accessory
Power (RAP) 0 212 .
Slide Switch
Express-Open/Express-Close : To
express-open the sunroof, fully
press and release
I (1). To
express-close the sunroof, fully press and release
K (1). Press
the switch again to stop the
movement.
Open/Close (Manual Mode) : To
open the sunroof, press and hold
I(1). Release the switch at the
desired position. Press and hold
K (1) to close the sunroof.
Release the switch at the desired
position.
Tilt Switch
Vent : From the closed position,
press
J (2) to vent the sunroof.
Press
K (2) to close the
sunroof 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Keys, Doors, and Windows 27
Keys, Doors, and
Windows Keys and Locks Keys (Keyless Access) . . . . . . . . 27
Keys (Key Access) . . . . . . . . . . . . 28
Remote Keyless Entry (RKE)
System . . . . . . . . . . . . . . . . . . . . . . . 31
Remote Keyless Entry (RKE)
System Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 31
Remote Keyless Entry (RKE)
System Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 33
Remote Vehicle Start . . . . . . . . . . 39
Door Locks . . . . . . . . . . . . . . . . . . . . 41
Power Door Locks . . . . . . . . . . . . . 42
Delayed Locking . . . . . . . . . . . . . . . 42
Automatic Door Locks . . . . . . . . . 42
Lockout Protection . . . . . . . . . . . . . 42
Safety Locks . . . . . . . . . . . . . . . . . . . 43
Doors Liftgate . . . . . . . . . . . . . . . . . . . . . . . . 43
Power Assist Steps . . . . . . . . . . . . 48
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 49
Vehicle Alarm System . . . . . . . . . 49 Immobilizer . . . . . . . . . . . . . . . . . . . . 51
Immobilizer Operation . . . . . . . . . 51
Exterior Mirrors Convex Mirrors . . . . . . . . . . . . . . . . 52
Power Mirrors . . . . . . . . . . . . . . . . . . 53
Folding Mirrors . . . . . . . . . . . . . . . . . 53
Heated Mirrors . . . . . . . . . . . . . . . . . 54
Automatic Dimming Mirror . . . . . 54
Blind Spot Mirrors . . . . . . . . . . . . . . 54
Reverse Tilt Mirrors . . . . . . . . . . . . 55
Interior Mirrors Interior Rearview Mirrors . . . . . . . 55
Manual Rearview Mirror . . . . . . . . 55
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 56
Child-View Mirror . . . . . . . . . . . . . . 56
Windows Windows . . . . . . . . . . . . . . . . . . . . . . . 56
Power Windows . . . . . . . . . . . . . . . 56
Sun Visors . . . . . . . . . . . . . . . . . . . . . 58
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 58 Keys and Locks Keys (Keyless Access)
{ WarningLeaving children in a vehicle with
an ignition key or Remote
Keyless Entry (RKE) transmitter is
dangerous and children or others
could be seriously injured or
killed. They could operate the
power window or other controls or
make the vehicle move. The
windows will function with the key
in the ignition or with the RKE
transmitter in the vehicle, and
children or others could be caught
in the path of a closing window.
Do not leave children in a vehicle
with the ignition key or an RKE
transmitter.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
30 Keys, Doors, and Windows
Interference from radio-frequency
identification (RFID) tags may
prevent the key from starting the
vehicle. Keep RFID tags away from
the key when starting the vehicle.
The key is used for the driver door,
ignition, and glove box.
If equipped with memory seats,
keys 1 and 2 are linked to seating
positions of memory 1 or 2. See
Memory Seats 0 64 .
Programming Keys to the
Vehicle
Follow these procedures to program
up to eight keys to the vehicle. Programming with Two
Recognized Keys (Key
Vehicles Only)
To program a new key:
1. Insert the original, already
programmed key in the ignition
and turn the ignition on without
starting the engine.
2. Turn the ignition off and
remove the key.
3. Quickly, within five seconds,
insert the second original
already programmed key in the
ignition and turn the ignition on
without starting the engine.
4. Turn the ignition off and
remove the key.
5. Insert the new key to be
programmed, and within
five seconds, turn the ignition
on without starting the engine.
The security light will turn off
once the key has been
programmed.
6. Repeat Steps 1 – 5 if additional
keys are to be programmed. If a key is lost or damaged, see your
dealer to have a new key made.
Programming without Recognized
Keys (Key Vehicles Only)
Program a new key to the vehicle
when a recognized key is not
available. Canadian regulations
require that Canadian owners see
their dealer.
If two currently recognized keys are
not available, follow this procedure
to program the first key.
This procedure will take
approximately 30 minutes to
complete for the first key. The
vehicle must be off and all of the
keys must be with you.
1. Insert the new vehicle key into
the ignition.
2. Turn the ignition on without
starting the engine. The
security light will come on.
3. Wait 10 minutes until the
security light turns off.
4. Turn the ignition off.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Keys, Doors, and Windows 45Power Liftgate Operation
{ WarningYou or others could be injured if
caught in the path of the power
liftgate. Make sure there is no one
in the way of the liftgate as it is
opening and closing.
CautionDriving with an open and
unsecured liftgate may result in
damage to the power liftgate
components. If equipped, the switch is on the
overhead console. The vehicle must
be in P (Park).
The modes are:
MAX : Opens to maximum height.
3/4 : Opens to a reduced height that
can be set from 3/4 to fully open.
Use to prevent the liftgate from
opening into overhead objects such
as a garage door or roof-mounted
cargo. The liftgate can be opened
all the way manually.
OFF : Opens manually only. To open or close the liftgate, select
MAX or 3/4 mode and then:
.
Press
b twice quickly on the
RKE transmitter until the liftgate
moves.
.
Press
8 on the overhead
console. The driver door must
be unlocked.
.
Press the touch pad on the
underside of the liftgate handle
after unlocking all doors.
If equipped with Keyless Access,
a locked vehicle can be opened
if the RKE transmitter is within
1 m (3 ft) of the touch pad.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Keys, Doors, and Windows 49power assist steps, clear the ice,
then enable the assist steps and
confirm normal function prior to use.
Keep hands, children, pets, objects,
and clothing clear of the power
assist steps when in motion. The
steps will reverse direction if they
encounter an obstruction when
opening or closing. Remove the
obstruction, then open and close the
door on the same side to complete
the motion of the assist steps. If the
obstruction is not cleared, the assist
steps remain extended while driving. To extend both power assist steps
for cleaning, press
j while the
vehicle is in P (Park) or N (Neutral).
Press
j again to retract them.
The DIC will display a message.
Enable/Disable
Press and hold
j for four seconds
to lock and disable the power assist
steps. Press and hold
j for
four seconds again to enable them.
The DIC will display a message.
Vehicle Security This vehicle has theft-deterrent
features; however, they do not make
the vehicle impossible to steal.
Vehicle Alarm System
The indicator light, on the
instrument panel near the
windshield, indicates the status of
the system.
Off : Alarm system is disarmed.
On Solid : Vehicle is secured
during the delay to arm the system.
Fast Flash : Vehicle is unsecured.
A door, liftgate, or the hood is open.
Slow Flash : Alarm system is
armed.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
Keys, Doors, and Windows 51The inclination sensor can set off
the alarm if it senses movement of
the vehicle, such as a change in
vehicle orientation.
The intrusion sensor monitors the
vehicle interior, and can activate the
alarm if it senses unauthorized entry
into the vehicle ’ s interior. Do not
allow passengers or pets to remain
in the vehicle when the intrusion
sensor is activated.
Before arming the theft-deterrent
system and activating the intrusion
sensor:
.
Make sure all doors and
windows are completely closed.
.
Secure any loose items such as
a sunshades.
.
Make sure there are no
obstructions blocking the
sensors in the front overhead
console.
.
Close DVD screens before
leaving the vehicle. Intrusion and Inclination
Sensors Disable Switch
It is recommended that the intrusion
and inclination sensors be
deactivated if pets are left in the
vehicle or the vehicle is being
transported.
With the vehicle off, press
o in
the front overhead console to turn
off the feature.
The indicator light will come on
momentarily, indicating that these
sensors have been disabled until
the next time the alarm system is
armed. Immobilizer See Radio Frequency Statement
0 396 .
Immobilizer Operation
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The system is automatically
disarmed when the ignition is turned
from off to on.
The security light, in the instrument
cluster, comes on if there is a
problem with arming or disarming
the theft-deterrent system.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
52 Keys, Doors, and Windows When trying to start the vehicle, the
security light comes on briefly when
the ignition is turned on.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the engine still does not start, and
the key appears to be undamaged,
try another ignition key. It may be
necessary to check the fuse. See
Fuses and Circuit Breakers 0 309 .
If the engine still does not start with
the other key, the vehicle needs
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the immobilizer
system to learn new or replacement
keys. Up to eight keys can be
programmed for the vehicle. To
program additional keys, see Keys
(Keyless Access) 0 27 or Keys (Key
Access) 0 28 . To program additional
transmitters, see your dealer.
Do not leave the key or device that
disarms or deactivates the vehicle
theft system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system. Exterior Mirrors Convex Mirrors
{ WarningA convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - crc - 6/20/17
60 Seats and Restraints
Seats and
Restraints Head Restraints Head Restraints . . . . . . . . . . . . . . . 61
Front Seats Power Seat Adjustment . . . . . . . . 62
Lumbar Adjustment . . . . . . . . . . . . 63
Reclining Seatbacks . . . . . . . . . . . 63
Memory Seats . . . . . . . . . . . . . . . . . 64
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . 67
Rear Seats Rear Seats . . . . . . . . . . . . . . . . . . . . 68
Heated Rear Seats . . . . . . . . . . . . 69
Second Row Seats . . . . . . . . . . . . 69
Third Row Seats . . . . . . . . . . . . . . . 74
Seat Belts Seat Belts . . . . . . . . . . . . . . . . . . . . . 76
How to Wear Seat Belts
Properly . . . . . . . . . . . . . . . . . . . . . . 77
Lap-Shoulder Belt . . . . . . . . . . . . . 78
Seat Belt Use During
Pregnancy . . . . . . . . . . . . . . . . . . . . 82
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . 83
Seat Belt Extender . . . . . . . . . . . . . 83 Safety System Check . . . . . . . . . . 83
Seat Belt Care . . . . . . . . . . . . . . . . . 84
Replacing Seat Belt System
Parts after a Crash . . . . . . . . . . . 84
Airbag System Airbag System . . . . . . . . . . . . . . . . . 85
Where Are the Airbags? . . . . . . . 86
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . 88
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . 89
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 89
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . 90
Passenger Sensing System . . . 91
Servicing the Airbag-Equipped
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 95
Adding Equipment to the
Airbag-Equipped Vehicle . . . . . 95
Airbag System Check . . . . . . . . . . 96
Replacing Airbag System Parts
after a Crash . . . . . . . . . . . . . . . . . 96
Child Restraints Older Children . . . . . . . . . . . . . . . . . 97
Infants and Young Children . . . . 98
Child Restraint Systems . . . . . . 101
Where to Put the Restraint . . . 102 Lower Anchors and Tethers for
Children (LATCH System) . . . 104
Replacing LATCH System
Parts After a Crash . . . . . . . . . . 111
Securing Child Restraints (With
the Seat Belt in the
Rear Seat) . . . . . . . . . . . . . . . . . . 112
Securing Child Restraints (With
the Seat Belt in the Center
Front Seat) . . . . . . . . . . . . . . . . . . 114
Securing Child Restraints (With
the Seat Belt in the Front
Passenger Seat) . . . . . . . . . . . . 114