2023 GMC YUKON service

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
198 Driving and Operating
On new vehicles, the various mechanical and
electrical systems experience a“break-in”
period during the first 6 400 km (4,000 mi)
of routine driving. As the vehicle is driven,
the mechanical systems adjust to provide
optimal fuel economy and transmission shift
performance.
Electrical systems will adapt and calibrate
during the break-in period. A one-time
occurrence of clicks and similar vehicle
noises is normal during this process.
Normal driving charges the vehicle’s battery
to achieve the best operation of the vehicle,
including fuel economy and the Stop/Start
System. See Stop/Start System 0200.Ignition Positions
Vehicles equipped with Keyless Access have
pushbutton starting.
The Remote Key must be in the vehicle for
the system to operate. If the pushbutton
start is not working, the vehicle may be
near a strong radio antenna signal causing
interference to the Keyless Access system.
See Remote Key Operation 08.
To shift out of P (Park), the ignition must be
on or in Service Mode, and the brake pedal
must be applied.
{Warning
Turning off the vehicle while moving may
cause loss of power assist in the brake
and steering systems and disable the
airbags. While driving, only shut the
vehicle off in an emergency.
Stopping the Engine/LOCK/OFF (No Indicator
Lights) : When the vehicle is stopped, press
ENGINE START/STOP once to turn the
engine off.
If the vehicle is in P (Park), the ignition will
turn off, and Retained Accessory Power (RAP)
will remain active. See Retained Accessory
Power (RAP) 0201.
If the vehicle is not in P (Park), the ignition
will return to accessory mode and display
the message SHIFT TO PARK in the Driver
Information Center (DIC). When the vehicle is
shifted into P (Park), the ignition system will
turn off.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 199
The vehicle may have an electric steering
column lock. The lock is activated when the
ignition is turned off and either front door is
opened. A sound may be heard as the lock
actuates or releases. The steering column
lock may not release with the wheels turned
off center. If this happens, the vehicle may
not start. Move the steering wheel from left
to right while attempting to start the
vehicle. If this does not work, the vehicle
needs service.
If the vehicle must be shut off in an
emergency:1. Brake using a firm and steady pressure. Do not pump the brakes repeatedly. This
may deplete power assist, requiring
increased brake pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the vehicle is moving.
After shifting to N (Neutral), firmly apply
the brakes and steer the vehicle to a
safe location.
3. Come to a complete stop. Hold the brake pedal down and shift to P (Park). The
vehicle must be in P (Park) to turn the
ignition off.
4. Continue to hold the brake pedal down. 5. Set the parking brake. See
Electric
Parking Brake 0212.
6. Press ENGINE START/STOP once to turn the ignition off.
7. Release the brake pedal.
If the vehicle cannot be pulled over, and
must be shut off while driving, press and
hold ENGINE START/STOP for longer than
two seconds, or press twice in five seconds.
Accessory Mode (Amber Indicator Light) :
This mode allows some electrical accessories
to be used when the engine is off.
With the ignition off, pressing the button
one time without the brake pedal applied
will place the ignition system in
accessory mode.
The ignition will switch from accessory
mode to off after five minutes to prevent
battery rundown.
ON/RUN/START (Green Indicator Light) : This
mode is for driving and starting. With the
ignition off, and the brake pedal applied,
pressing the button once will turn the
ignition on. Once engine cranking begins,
release the button. Engine cranking will
continue until the engine starts. See Starting
the Engine 0199. Service Mode
This power mode is available for service and
diagnostics, and to verify the proper
operation of the malfunction indicator lamp
as may be required for emission inspection
purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the button for more than
five seconds will place the vehicle in Service
Mode. The instruments and audio systems
will operate as they do when the ignition is
on, but the vehicle will not be able to be
driven. The engine will not start in Service
Mode. Press the button again to turn the
ignition off.
Starting the Engine
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
Caution
If you add electrical parts or accessories,
you could change the way the engine
operates. Any resulting damage would
not be covered by the vehicle warranty.
See
Add-On Electrical Equipment 0305.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 203
shift out of P (Park). If all of these are met
but the vehicle will not shift out of P (Park),
see your dealer for service.
Parking over Things That Burn
{Warning
Things that can burn could touch hot
exhaust parts under the vehicle and
ignite. Do not park over papers, leaves,
dry grass, or other things that can burn.
Dynamic Fuel Management
If equipped, Dynamic Fuel Management
allows the engine to operate in multiple
cylinder patterns, up to the full 8-cylinder
operation, depending on driving conditions.
When less power is required, such as
cruising at a constant vehicle speed, the
system will reduce any combination of
operating cylinders enabling the vehicle to
achieve better fuel economy. When greater
power is required, such as passing or
merging onto a freeway, the system will
maintain full 8-cylinder operation.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running, be
sure it will not move and there is adequate
ventilation.
SeeShifting Into Park 0201 and
Engine Exhaust 0203.
If the vehicle is left parked and running with
the remote key outside the vehicle, it will
continue to run for up to 15 minutes.
If the vehicle is left parked and running with
the remote key inside the vehicle, it will
continue to run for up to 30 minutes.
The vehicle could turn off sooner if it is
parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is taken
out of P (Park) while it is running.
Engine Exhaust
{
Warning
Engine exhaust contains carbon monoxide
(CO), which cannot be seen or smelled.
Exposure to CO can cause
unconsciousness and even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with poor
ventilation (parking garages, tunnels,
deep snow that may block underbody
airflow or tail pipes).
.The exhaust smells or sounds strange
or different.
.The exhaust system leaks due to
corrosion or damage.
.The vehicle exhaust system has been
modified, damaged, or improperly
repaired.
.There are holes or openings in the
vehicle body from damage or
aftermarket modifications that are not
completely sealed. (Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 213
The system has a red EPB status light and
an amber service EPB warning light. See
Electric Parking Brake Light0115 and
Service Electric Parking Brake Light 0115.
There are also parking brake-related Driver
Information Center (DIC) messages.
Before leaving the vehicle, check the red EPB
status light to ensure that the EPB is
applied.
If a message displays on the DIC indicating
the transmission is unable to shift soon, the
service electric parking brake is on, and the
EPB light flashes at the same time, the
system must be reset. Start the vehicle,
apply the EPB, and then release it. The
message and the light should turn off. See
Electric Parking Brake Light 0115 and
Service Electric Parking Brake Light 0115.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch.
The red EPB status light will flash and then
stay on once the EPB is fully applied. If the
red EPB status light flashes continuously,
then the EPB is only partially applied or
there is a problem with the EPB. A DIC message will display. Release the EPB and
try to apply it again. If the light does not
come on, or keeps flashing, have the vehicle
serviced. Do not drive the vehicle if the red
EPB light is flashing. See your dealer.
If the amber service EPB warning light is on,
press the EPB switch. Continue to hold the
switch until the red EPB status light remains
on. If the amber service EPB warning light is
on, see your dealer.
If the EPB is applied while the vehicle is
moving, the vehicle will decelerate as long
as the switch is pressed. If the switch is
pressed until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply the EPB
in some situations when the vehicle is not
moving. This is normal, and is done to
periodically check the correct operation of
the EPB system, or as required by other
safety functions that utilize the EPB.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to accessory mode. 2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the red EPB status
light is off.
If the amber service EPB warning light is on,
release the EPB by pressing and holding the
EPB switch. Continue to hold the switch
until the red EPB status light is off. If either
light stays on after release is attempted, see
your dealer.
Caution
Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake
system parts. Make sure that the parking
brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and parking on a
hill, see Driving Characteristics and Towing
Tips 0277.
Automatic EPB Release
The EPB automatically releases if the vehicle
is running, placed into gear, and an attempt
is made to drive. Avoid rapid acceleration
when the EPB is applied to preserve parking
brake lining life.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
222 Driving and Operating
Off-Road Driver Mode and Terrain Driver
Mode will automatically set Increased
Height when vehicle speed is less than
80 km/h (50 mph). If vehicle speed exceeds
80 km/h (50 mph), the vehicle will lower to
Normal Height. Normal Height will be
maintained until vehicle speed is slowed to
less than 16 km/h (10 mph) and then the
vehicle will automatically raise back to
Increased Height.
The vehicle will automatically lower from
Increased Height to Normal Height to
provide improved stability if aggressive
maneuvers are detected.
Maximum Height
Maximum Height is 50 mm (2 in) higher
than Normal Height. This ride height raises
the vehicle for off-road use and is only
available with specific optional content.
To raise the vehicle to Maximum Height,
first shift the transfer case to 4
n. Once the
transfer case is in 4
nand vehicle speed is
less than 48 km/hr (30 mph), select
Maximum Height in the Ride Height Menu.
If vehicle speed exceeds 48 km/h, the
vehicle will automatically lower to Increased
Height. The vehicle will automatically lower from
Maximum Height to Normal Height to
provide improved stability if aggressive
maneuvers are detected.
Aerodynamic Height
Aerodynamic Height is 20 mm (0.75 in)
lower than Normal Height. This ride height
lowers the vehicle at higher vehicle speeds
to improve aerodynamics.
The vehicle will lower to Aerodynamic
Height when vehicle speed exceeds
105 km/h (65 mph) for a period of time. The
vehicle will raise to Normal Height when the
vehicle slows to less than 48 km/h
(30 mph).
Aerodynamic Height is automatically
disabled when a trailer is connected to the
vehicle or Tow/Haul Driver Mode is active.
Suspension Modes
The air suspension has two special modes
located in the infotainment screen under
Settings/Vehicle/Suspension. When either is
active, the following amber icon will be
illuminated in the instrument cluster.
See
Four Corner Air Suspension Light 0119.
Service Mode
Service Mode will disable all air suspension
operation including raising and lowering the
vehicle and operation of the air compressor.
This mode is useful when the vehicle is
being towed on a flat bed or when any
work under the vehicle is being performed.
Service Mode is automatically enabled when
the vehicle is put on a hoist or a floor jack
is used to raise a corner. Service Mode may
temporarily enable during intense off-road
situations to prevent damaging air
suspension activity. Service Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Alignment Mode
Alignment Mode will optimize the vehicle
height to provide the most accurate wheel
alignment. This mode should be enabled
once the vehicle is driven onto the
alignment station.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 223
To enable Alignment Mode, ensure the
vehicle is at Normal Height and shift the
vehicle to Neutral. Alignment Mode
automatically disables when vehicle speed
exceeds 16 km/h (10 mph).
Air Suspension Operation with Door(s) or
Hood Open
The air suspension will temporarily suspend
all height changes while the hood or any
door is open. The air suspension resumes
height changes once the hood and all doors
are closed. An open rear liftgate does not
suspend the air suspension operation.
System Over-Temperature
If the air suspension is under heavy use, the
system may temporarily suspend all height
changes to allow compressor cooldown.
When this occurs and a height change is
requested, a‘Leveling System Unavailable’
message will be displayed in the instrument
cluster.
Suspension Lowered for Stability
In the event of a loss of Electronic Stability
Control, the air suspension will lower the
vehicle at higher speeds to provide increased
stability. This will be accompanied by a
‘Vehicle Lowering for Stability’ message in
the instrument cluster. Excessive Vehicle Loading
If the air suspension detects excessive
vehicle loading, it will not raise above
Normal Height.
Air Suspension Service
If a
‘Service Leveling System’ message is
displayed in the instrument cluster, see your
authorized dealer immediately.
Cruise Control
{
Warning
Cruise control can be dangerous where
you cannot drive safely at a steady
speed. Do not use cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
excessive wheel slip, and you could lose
control. Do not use cruise control on
slippery roads. If equipped with cruise control, a speed of
about 40 km/h (25 mph) or more can be
maintained without keeping your foot on
the accelerator. Cruise control does not work
at speeds below about 40 km/h (25 mph).
If the cruise control is being used and the
Traction Control System (TCS) or StabiliTrak/
Electronic Stability Control (ESC) begins to
limit wheel spin, the cruise control will
automatically disengage. See
Traction
Control/Electronic Stability Control 0214. If a
collision alert occurs when cruise control is
activated, cruise control is disengaged. See
Forward Collision Alert (FCA) System 0264.
When road conditions allow you to safely
use it again, cruise control can be turned
back on.
Turning off the TCS or StabiliTrak/ESC
system will disengage the cruise control.
If the brakes are applied, cruise control
disengages.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
Driving and Operating 233
{Warning
The ACC will not automatically apply the
brakes if your foot is resting on the
accelerator pedal. You could crash into a
vehicle ahead of you.
Curves in the Road
{Warning
On curves, ACC may not detect a vehicle
ahead in your lane. You could be startled
if the vehicle accelerates up to the set
speed, especially when following a vehicle
exiting or entering exit ramps. You could
lose control of the vehicle or crash. Do
not use ACC while driving on an entrance
or exit ramp. Always be ready to use the
brakes if necessary.
{Warning
On curves, ACC may respond to a vehicle
in another lane, or may not have time to
react to a vehicle in your lane. You could
crash into a vehicle ahead of you, or lose
control of your vehicle. Give extra (Continued)
Warning (Continued)
attention in curves and be ready to use
the brakes if necessary. Select an
appropriate speed while driving in curves.
ACC may operate differently in a sharp
curve. It may briefly reduce the vehicle
speed if the curve is too sharp.
The curve speed control indicator
bmay
illuminate green when ACC is actively
controlling the vehicle speed and detects a
sharp curve on the road ahead.
ACC automatically slows the vehicle down
while navigating the curve and may increase
speed out of the curve, but will not exceed
the set speed.
When following a vehicle and entering a
curve, ACC may not detect the vehicle ahead
and accelerate to the set speed. When this
happens, the vehicle ahead indicator will not
appear.
ACC may detect a vehicle that is not in your
lane and apply the brakes.
ACC may occasionally provide an alert
and/or braking that is considered
unnecessary. It could respond to vehicles in
different lanes or stationary objects when
entering or exiting a curve. This is normal
operation. The vehicle does not need service.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-16417394) - 2023 - CRC - 5/16/22
236 Driving and Operating
this section and the ACC section before
using Super Cruise. SeeAdaptive Cruise
Control (Advanced) 0225.
An active Connected Service plan that
includes Super Cruise Services is required to
use Super Cruise.
{Warning
Super Cruise does not perform all aspects
of driving, nor does it do everything a
driver can do. Super Cruise only steers to
maintain vehicle position in the current
lane or, under some circumstances, to
change lanes. Super Cruise can only be
used with Adaptive Cruise Control.
Super Cruise does:
.Not prevent crashes or warn of
possible crashes.
.Not steer to avoid stopped or
slow-moving vehicles, cross-traffic,
construction barriers or cones,
motorcycles, children, pedestrians,
animals, or other objects on the road.
.Not steer in response to vehicles or
objects next to your vehicle, including
vehicles attempting to enter your lane. (Continued)
Warning (Continued)
.Not respond to traffic lights, stop
signs, or other traffic control devices.
.Not respond to crossing traffic.
.Not make turns.
.Not steer to merge onto or to exit
highways.
.Not steer to avoid, or steer through
construction zones.
.Not function on surface streets.
.Not respond to oncoming traffic.
.Not function in city driving conditions.
{Warning
Some state and local laws may require
hands to be kept on the steering wheel
at all times. Only remove your hands
from the steering wheel if Super Cruise is
engaged, it is safe to do so, and it is
permitted by state and local laws.
{Warning
Failure to supervise the driving task and
to respond appropriately, even while
Super Cruise is operating, can cause a
crash. Super Cruise may not respond as
you would to all driving situations and
may not maintain lane position under all
conditions.
It is extremely important to pay
attention to the operation of the vehicle,
even while using Super Cruise. Do not
use a hand-held device while driving,
even with Super Cruise engaged. To
prevent serious injury or death:
.Always remain properly seated in the
driver seat with your seat belt
fastened.
.Never remove your hands from the
steering wheel when Super Cruise is
not operating.
.Always make sure traffic conditions
are safe before using Super Cruise.
.Always keep the entire vehicle and the
sensors clean. Sensors are on the
front, sides, and rear of the vehicle.(Continued)