2020 GMC YUKON ECU

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 9
Keys, Doors, and
Windows
Keys and Locks
Keys (Keyless Access) . . . . . . . . . . 9
Keys (Key Access) . . . . . . . . . . . . 10
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 16
Remote Vehicle Start . . . . . . . . . . 23
Door Locks . . . . . . . . . . . . . . . . . . . . 24
Power Door Locks . . . . . . . . . . . . . 25
Delayed Locking . . . . . . . . . . . . . . . 25
Automatic Door Locks . . . . . . . . . 25
Lockout Protection . . . . . . . . . . . . . 26
Safety Locks . . . . . . . . . . . . . . . . . . . 26
Doors
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . 27
Power Assist Steps . . . . . . . . . . . . 32
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 33
Vehicle Alarm System . . . . . . . . . 33 Steering Column Lock . . . . . . . . . 35
Immobilizer . . . . . . . . . . . . . . . . . . . . 36
Immobilizer Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 36
Immobilizer Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 36
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 37
Power Mirrors . . . . . . . . . . . . . . . . . . 38
Folding Mirrors . . . . . . . . . . . . . . . . . 38
Heated Mirrors . . . . . . . . . . . . . . . . . 39
Automatic Dimming Mirror . . . . . 39
Blind Spot Mirrors . . . . . . . . . . . . . . 39
Reverse Tilt Mirrors . . . . . . . . . . . . 40
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 41
Manual Rearview Mirror . . . . . . . . 41
Automatic Dimming RearviewMirror . . . . . . . . . . . . . . . . . . . . . . . . . 41
Child-View Mirror . . . . . . . . . . . . . . 41
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 41
Power Windows . . . . . . . . . . . . . . . 42
Sun Visors . . . . . . . . . . . . . . . . . . . . . 43
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 44
Keys and Locks
Keys (Keyless Access)
{Warning
Leaving 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-13566587) - 2020 - CRC - 4/15/19
12 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 can be used for the ignition,
and all locks.
If equipped with memory seats,
keys 1 and 2 are linked to seating
positions of memory 1 or 2. See
Memory Seats051.
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 13
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.
5. Repeat Steps 2–4 two more times. After the third time, turn
the ignition on; the key is
learned and all previously
known keys will no longer work
with the vehicle.
6. To learn the second key, turn the ignition off, insert the
second key to be learned, and
turn the ignition on without
starting the engine. After the two keys are learned,
remaining keys can be learned by
following the procedure in
“Programming with Two Recognized
Keys (Key Vehicles Only).”
See your dealer if a replacement
key or additional key is needed.
If locked out of the vehicle, see
Roadside Assistance Program
0
400.
With an active OnStar or connected
service plan, an OnStar Advisor
may remotely unlock the vehicle.
See OnStar Overview 0410.
Remote Keyless Entry
(RKE) System
See Radio Frequency Statement
0 405.
If there is a decrease in the Remote
Keyless Entry (RKE) operating
range:
. Check the distance. The
transmitter may be too far from
the vehicle. .
Check the location. Other
vehicles or objects may be
blocking the signal.
. Check the transmitter's battery.
See “Battery Replacement” later
in this section.
. If the transmitter is still not
working correctly, see your
dealer or a qualified technician
for service.
Remote Keyless Entry
(RKE) System Operation
(Key Access)
The RKE transmitter functions may
work up to 60 m (197 ft) away from
the vehicle.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 013.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
28 Keys, Doors, and Windows
There will be a delay in the release
of the liftglass if there is an attempt
to open it while the rear wiper is in
motion.
Use the pull cup to lower and close
the liftgate. Do not press the touch
pad while closing the liftgate. This
will cause the liftgate to be
unlatched.
The liftgate can be opened when
locked if the RKE transmitter is
within 1 m (3 ft) of the touch pad.
SeeRemote Keyless Entry (RKE)
System Operation (Key Access)
0 13 or
Remote Keyless Entry (RKE)
System Operation (Keyless Access)
0 16.
The liftgate has an electric latch.
If the battery is disconnected or has
low voltage, the liftgate will not
open. The liftgate will resume
operation when the battery is
reconnected and charged.Power Liftgate Operation
{Warning
You 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.
Caution
Driving with an open and
unsecured liftgate may result in
damage to the power liftgate
components.
If equipped, the power liftgate
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 obstructions
such as a garage door or
roof-mounted cargo. The liftgate can
be opened manually all the way.
OFF : Opens manually only.
To power open or close the liftgate,
select MAX or 3/4 mode and then:

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 29
.Pressbtwice quickly on the
RKE transmitter until the liftgate
moves.
. Press
8on the overhead
console. The driver door must
be unlocked or locked without
the security armed.
. 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.
.Presslon the bottom edge of
the liftgate next to the latch to
close.
Press any liftgate button, the touch
pad, or
bon the RKE transmitter
while the liftgate is moving to stop it.
Pressing any liftgate button or
pressing
btwice quickly on the
RKE transmitter restarts the
operation in the reverse direction.
Pressing the touch pad on the
liftgate handle will restart the
motion, but only in the opening
direction.
Caution
Manually forcing the liftgate to
open or close during a power
cycle can damage the vehicle.
Allow the power cycle to
complete.
The power liftgate may be
temporarily disabled in extremely
low temperatures, or after repeated
power cycling over a short period of time. If this occurs, the liftgate can
still be operated manually. Select
OFF on the liftgate switch.
If the vehicle is shifted out of
P (Park) while the power function is
in progress, the liftgate will continue
to completion. If the vehicle is
accelerated before the liftgate has
completed moving, the liftgate may
stop or reverse direction. Check for
Driver Information Center (DIC)
messages and make sure the
liftgate is closed and latched before
driving.
Falling Liftgate Detection
If the power liftgate automatically
closes after a power opening cycle,
it indicates that the system is
reacting to excess weight on the
liftgate or a possible support strut
failure. Remove any excess weight.
A repetitive chime will sound while
the falling liftgate detection feature
is operating. If the liftgate continues
to automatically close after opening,
see your dealer for service before
using the power liftgate.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Keys, Doors, and Windows 33
Enable/Disable
Press and hold
jfor four seconds
to lock and disable the power assist
steps. Press and hold
jfor
four seconds again to enable them.
The DIC will display a message.
Auto Power Assist Steps
This allows the feature to be turned
on or off. See Vehicle
Personalization 0152. Select Off,
On, or Extended.
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.
Arming the Alarm System
1. Turn off the vehicle.
2. Lock the vehicle in one of three ways:
.Use the RKE transmitter.
. Use the Keyless Access
system.
. With a door open, press
Q
on the interior of the door.
3. After 30 seconds the alarm system will arm, and the
indicator light will begin to
slowly flash. Pressing
Qon the
RKE transmitter a second time
will bypass the 30-second
delay and immediately arm the
alarm system.
The vehicle alarm system will not
arm if the doors are locked with
the key.
If the driver door is opened without
first unlocking with the RKE
transmitter, the horn will chirp and
the lights will flash to indicate
pre-alarm. If the vehicle is not
started, or the door is not unlocked

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
34 Keys, Doors, and Windows
by pressingKon the RKE
transmitter during the 10-second
pre-alarm, the alarm will be
activated.
The alarm will also be activated if a
passenger door, the liftgate, or the
hood is opened without first
disarming the system. When the
alarm is activated, the turn signals
flash and the horn sounds for about
30 seconds. The alarm system will
then re-arm to monitor for the next
unauthorized event.
Disarming the Alarm System
To disarm the alarm system or turn
off the alarm if it has been activated:
. Press
Kon the RKE transmitter.
. Unlock the vehicle using the
Keyless Access system.
. Start the vehicle.
To avoid setting off the alarm by
accident:
. Lock the vehicle after all
occupants have exited. .
Always unlock a door with the
RKE transmitter, or use the
Keyless Access system.
Unlocking the driver door with
the key will not disarm the
system or turn off the alarm.
How to Detect a Tamper
Condition
IfKis pressed on the RKE
transmitter and the horn chirps three
times, an alarm occurred previously
while the alarm system was armed.
If the alarm has been activated, a
message will appear on the DIC.
Power Sounder, Inclination
Sensor, and Intrusion Sensor
In addition to the standard
theft-deterrent system features, this
system may also have a power
sounder, inclination sensor, and
intrusion sensor.
The power sounder provides an
audible alarm which is distinct from
the vehicle’ s horn. It has its own power source, and can sound an
alarm if the vehicle’s battery is
compromised.
The 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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
36 Keys, Doors, and Windows
Immobilizer
SeeRadio Frequency Statement
0 405.
Immobilizer Operation
(Key Access)
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. 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
0315.
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) 09or
Keys (Key Access) 010. 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.
Immobilizer Operation
(Keyless Access)
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 transmitter
leaves the vehicle.
The immobilization system is
disarmed when ENGINE START/
STOP is pressed and a valid
transmitter is found in the vehicle.