2023 GMC SIERRA ignition

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 369
If they are, it could cause an unwanted
ground connection. You would not be
able to start your vehicle, and the bad
grounding could damage the electrical
systems.
To avoid the possibility of the vehicles
rolling, set the parking brake firmly on
both vehicles involved in the jump start
procedure. Put the automatic
transmission in P (Park) before setting
the parking brake. If you have a
four-wheel-drive vehicle, be sure the
transfer case is in a drive gear, not in
N (Neutral).
Caution
If any accessories are left on or plugged
in during the jump starting procedure,
they could be damaged. The repairs
would not be covered by the vehicle
warranty. Whenever possible, turn off or
unplug all accessories on either vehicle
when jump starting.
4. Turn the ignition off on both vehicles. Unplug unnecessary accessories plugged
into the accessory power outlets. Turn
off the radio and all the lamps that are not needed. This will avoid sparks and
help save both batteries. And it could
save the radio!
5. Open the hood on the other vehicle and locate the positive (+) and negative (−)
terminal locations on that vehicle.
{Warning
An electric fan can start up even when
the engine is not running and can injure
you. Keep hands, clothing, and tools
away from any underhood electric fan.
{Warning
Using a match near a battery can cause
battery gas to explode. People have been
hurt doing this, and some have been
blinded. Use a flashlight if you need
more light.
Battery fluid contains acid that can burn
you. Do not get it on you. If you
accidentally get it in your eyes or on
your skin, flush the place with water and
get medical help immediately.
{Warning
Fans or other moving engine parts can
injure you badly. Keep your hands away
from moving parts once the engine is
running.
6. Check that the jumper cables do not have loose or missing insulation. If they
do, you could get a shock. The vehicles
could be damaged too.
Before you connect the cables, here are
some basic things you should know.
Positive (+) will go to positive (+) or to a
remote positive (+) terminal if the
vehicle has one. Negative (–) will go to a
heavy, unpainted metal engine part or to
a remote negative (–) terminal if the
vehicle has one.
Do not connect positive (+) to negative
(–) or you will get a short that would
damage the battery and maybe other
parts too. And do not connect the
negative (–) cable to the negative (–)
terminal on the dead battery because
this can cause sparks.
7. Connect one end of the red positive (+) cable to the discharged battery
positive (+) terminal.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 373
5. With the engine running, release theparking brake and verify that the
transfer case is in N (Neutral) by shifting
the transmission to D (Drive) and then to
R (Reverse). There should be no
movement while shifting the
transmission.
6. Shift the transmission to D (Drive).
7. If equipped with an ignition key, turn the ignition to ACC/ACCESSORY.
If equipped with Keyless Access, turn the
engine off. Disregard the Shift to P (Park)
DIC message. See Ignition Positions (Key
Access) 0221 or
Ignition Positions (Keyless Access) 0223.
{Warning
To avoid death, serious injury,
or property damage, before dinghy
towing the vehicle, always disconnect and
secure the negative battery cable and
cover the negative battery post and cable
with a non-conductive material. If the
battery is left connected or the battery
cable contacts the post, the Electric
Parking Brake may activate during
towing, which could cause a crash. 8. Disconnect the negative (–) battery
cable. See “Negative Battery Cable
Disconnection” inBattery - North
America 0319.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked, vehicle
damage may occur.
10. Move the steering wheel to make sure the steering column is unlocked.
11. If the vehicle has an ignition key, keep it in the towed vehicle in ACC/ACCESSORY
to prevent the steering column from
locking. If the vehicle is equipped with
Keyless Access, keep the RKE transmitter
outside of the vehicle and manually lock
the doors. Access the vehicle by using
the key in the door lock. See Door Locks
0 23.
Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North America 0319. 3. Turn on the ignition with the engine off.
For vehicles with a key, turn the ignition
to ON/RUN with the engine off. If the
vehicle is equipped with Keyless Access,
with your foot off the brake pedal, press
and hold ENGINE START/STOP for
five seconds until the green light comes
on in the button. See Ignition Positions
(Key Access) 0221 or
Ignition Positions (Keyless Access) 0223.
4. Set the parking brake. See Electric
Parking Brake 0239.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0123.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the ignition.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
388 Service and Maintenance
Systems, Fluids, and Visible Leak
Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth, and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration date,
if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air filter,
if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and u-joints
.Compartment lift struts, if equipped
.Floor mats secured, no interference with
pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
Special Application Services
.Vehicles with Dual Wheels: Check dual
wheel nut torque at 160, 1 600, and
10 000 km (100, 1,000, and 6,000 mi) of
driving. Repeat this service whenever a
tire/wheel is serviced or removed.
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See “Underbody Maintenance”
in Exterior Care 0374.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
OnStar 409
.Give OnStar Turn-by-Turn Navigation voice
commands.
.Obtain and customize the Wi-Fi hotspot
name or SSID and password, if equipped.
Press
Qto connect to an Advisor to:
.Verify account information or update
contact information.
.Get driving directions.
.Receive a Diagnostic check of the vehicle's
key operating systems.
.Receive Roadside Assistance.
.Manage Wi-Fi Settings, if equipped.
Press
>to get a priority connection to an
OnStar Advisor available 24/7 to:
.Get help for an emergency.
.Be a Good Samaritan or respond to an
AMBER Alert.
.Get assistance in severe weather or other
crisis situations and find evacuation
routes.
OnStar Services
Emergency
Emergency Services require an active safety
and security plan. With Automatic Crash
Response, built-in sensors can automatically
alert a specially trained OnStar Advisor who
is immediately connected in to the vehicle
to help.
Press
>for a priority connection to an
OnStar Advisor who can contact emergency
service providers, direct them to your exact
location, and relay important information.
With OnStar Crisis Assist, specially trained
Advisors are available 24 hours a day, 7 days
a week, to provide a central point of
contact, assistance, and information during a
crisis.
With Roadside Assistance, Advisors can
locate a nearby service provider to help with
a flat tire, a battery jump, or an empty
gas tank.
Security
If equipped, OnStar provides these services:
.With Stolen Vehicle Assistance, OnStar
Advisors can use GPS to pinpoint the
vehicle and help authorities quickly
recover it.
.With Remote Ignition Block, if equipped,
OnStar can block the vehicle from being
restarted.
.With Stolen Vehicle Slowdown,
if equipped, OnStar can work with law
enforcement to gradually slow the
vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked and the
vehicle alarm sounds, a notification by text,
e-mail, or phone call will be sent. If the
vehicle is stolen, an OnStar Advisor can work
with authorities to recover the vehicle.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
OnStar 411
TTY Users
OnStar has the ability to communicate to
deaf, hard-of-hearing, or speech-impaired
customers while in the vehicle. The available
TTY system can provide in-vehicle access to
all OnStar services, except Virtual Advisor
and OnStar Turn-by-Turn Navigation.
If equipped, TTY mode can be turned on or
off by touching Settings, then Apps, and
then Phone. When TTY mode is on, phone
calls can be made or received with OnStar
using the infotainment display.
OnStar Personal Identification
Number (PIN)
A PIN is needed to access some OnStar
services. The PIN will need to be changed
the first time when speaking with an
Advisor. To change the OnStar PIN, contact
an OnStar Advisor by pressing
Qor calling
1-888-4ONSTAR.
Warranty
OnStar equipment may be warranted as part
of the vehicle warranty.
Languages
The vehicle can be programmed to respond
in multiple languages. Press
Qand ask for
an Advisor. Advisors are available in English,
Spanish, and French. Available languages
may vary by country.
Potential Issues
OnStar cannot perform Remote Door Unlock
or Stolen Vehicle Assistance after the vehicle
has been off continuously for an extended
period of time without an ignition cycle. To
find out the duration of time that applies
for the vehicle, contact an OnStar Advisor by
pressing
Qor calling 1-888-4ONSTAR. If the
vehicle has not been started for an extended
period of time, OnStar can contact Roadside
Assistance or a locksmith to help gain access
to the vehicle.
Global Positioning System (GPS)
.Obstruction of the GPS can occur in a
large city with tall buildings; in parking
garages; around airports; in tunnels and
underpasses; or in an area with very
dense trees. If GPS signals are not
available, the OnStar system should still operate to call OnStar. However, OnStar
could have difficulty identifying the exact
location.
.In emergency situations, OnStar can use
the last stored GPS location to send to
emergency responders.
A temporary loss of GPS can cause loss of
the ability to send a Turn-by-Turn
Navigation route. The Advisor may give a
verbal route or may ask for a call back after
the vehicle is driven into an open area.
Cellular and GPS Antennas
Cellular reception is required for OnStar to
send remote signals to the vehicle. Do not
place items over or near the antenna to
prevent blocking cellular and GPS signal
reception.
Unable to Connect to OnStar Message
If there is limited cellular coverage or the
cellular network has reached maximum
capacity, this message may come on. Press
Qto try the call again or try again after
driving a few miles into another
cellular area.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Index 421
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Hazard Warning Flashers . . . . . . . . . . . . . . . . .142
HD Radio Technology . . . . . . . . . . . . . . . . . . . . 156
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Head-Up Display (HUD) . . . . . . . . . . . . . . . . . . . 132
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 325
Daytime Running Lamps (DRL) . . . . . . . . . . 141
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Headlamps, Front Turn Signal,Sidemarker, and Parking Lamps . . . . . . 325
High-Beam On Light . . . . . . . . . . . . . . . . . . . . 127
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 128
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 105
Ventilated Front Seats . . . . . . . . . . . . . . . . . . 56
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
High-Beam On Light . . . . . . . . . . . . . . . . . . . . . . 127 Hill
Descent Control (HDC) . . . . . . . . . . . . . . . . . 242
Descent Control Light . . . . . . . . . . . . . . . . . . 123
Hill and Mountain Roads . . . . . . . . . . . . . . . . . 212
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 240
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
How to Wear Seat Belts Properly . . . . . . . . . 59
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
I
If the System Needs Service . . . . . . . . . . . . . . 171
Ignition Positions . . . . . . . . . . . . . . . . . . . . 221, 223
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . . . . . 124
Indicators
Warning Lights and Gauges . . . . . . . . . . . . . 111
Infants and Young Children, Restraints . . . . .77
Information Publication Ordering . . . . . . . . . . . . . . . . . . . 404
Infotainment Using the System . . . . . . . . . . . . . . . . . . . . . . 152
Infotainment System . . . . . . . . . . . . . . . . . . . . 407
Inspection Multi-Point Vehicle . . . . . . . . . . . . . . . . . . . . 387
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . . 111
Instrument Panel Overview . . . . . . . . . . . . . . . . .5 Interior Rearview Mirrors . . . . . . . . . . . . . . . . . 40
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 148
J
Jack
Auxiliary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Jump
Starting - North America . . . . . . . . . . . . . . . 367
K
Keyless EntryRemote (RKE) System Operation . . . . . 12, 14
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8, 11
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . 338
Lamps Auxiliary Roof Mounted Lamp . . . . . . . . . 144
Daytime Running (DRL) . . . . . . . . . . . . . . . . . 141
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Exterior Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 144
Exterior Controls . . . . . . . . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . 147
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Fog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
High/Low Beam Changer . . . . . . . . . . . . . . . 141
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 327