2023 GMC SIERRA light

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 319
installed. Add or remove fluid, as necessary,
only when work is done on the brake
hydraulic system.
{Warning
If too much brake fluid is added, it can
spill on the engine and burn, if the
engine is hot enough. You or others could
be burned, and the vehicle could be
damaged. Add brake fluid only when
work is done on the brake hydraulic
system.
When the brake fluid falls to a low level,
the brake warning light comes on. See Brake
System Warning Light 0122.
Brake fluid absorbs water over time which
degrades the effectiveness of the brake fluid.
Replace brake fluid at the specified intervals
to prevent increased stopping distance. See
Maintenance Schedule 0385.
What to Add
Use only GM approved DOT 4 brake fluid
from a clean, sealed container. See
Recommended Fluids and Lubricants 0389.
{Warning
The wrong or contaminated brake fluid
could result in damage to the brake
system. This could result in the loss of
braking leading to a possible injury.
Always use the proper GM approved
brake fluid.
Caution
If brake fluid is spilled on the vehicle's
painted surfaces, the paint finish can be
damaged. Immediately wash off any
painted surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove the cap
and do not add fluid.
Refer to the replacement number shown on
the original battery label when a new
battery is needed. See Engine Compartment
Overview 0305 for battery location.
{Warning
WARNING: Battery posts, terminals and
related accessories can expose you to
chemicals including lead and lead
compounds, which are known to the
State of California to cause cancer and
birth defects or other reproductive harm.
Wash hands after handling. For more
information go to
www.P65Warnings.ca.gov.
See California Proposition 65 Warning 01.
Vehicle Storage
{Warning
Batteries have acid that can burn you and
gas that can explode. You can be badly
hurt if you are not careful. See Jump
Starting - North America 0367 for tips on
working around a battery without
getting hurt.
Infrequent Usage: Remove the black,
negative (−) cable from the battery to keep
the battery from running down.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 325
Liftgate
Headlamp Aiming
Front Headlamp Aiming
Headlamp aim has been preset and should
need no further adjustment.
If the vehicle is damaged in a crash, the
headlamp aim may be affected.
If adjustment to the headlamps is necessary,
see your dealer.
Bulb Replacement
For the proper type of replacement bulbs,
or any bulb changing procedure not listed in
this section, contact your dealer.
Caution
Do not replace incandescent bulbs with
aftermarket LED replacement bulbs. This
can cause damage to the vehicle electrical
system.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized gas inside
and can burst if you drop or scratch the
bulb. You or others could be injured. Be
sure to read and follow the instructions
on the bulb package.
LED Lighting
This vehicle has several LED lamps. For
replacement of any LED lighting assembly,
contact your dealer.
Headlamps, Front Turn Signal,
Sidemarker, and Parking Lamps
Base Level Headlamp Assembly
1. Turn Signal Lamps
Headlamp Replacement
See your dealer for headlamp replacement.
Turn Signal Lamp Replacement
Base Level1. Open the hood.
2. Turn the bulb socket counterclockwise to remove it from the headlamp assembly
and pull it straight out.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
336 Vehicle Care
FusesUsage
F1 Right Doors
F2 Left Doors
F3 Universal Garage Door Opener
F4 –
F5 –
F6 Front Blower
F8 Lumbar Switch
F10 Body Control Module 6/ Body Control Module 7
F11 Seat/Column Lock Module
F12 Body Control Module 3/ Body Control Module 5
F14 Mirrors/Windows Module F17 Steering Wheel Controls
F18 Video Processing Module/ Obstacle Detection
F19 DLIS –Discrete Logic
Ignition Switch
F20 Ventilated Seats F21 NOT R/C Fuses
Usage
F22 Heated Steering Wheel
F23 MISC R/C
F24 Power Take Off/Reflective Light Auxiliary Display/
Instrument Panel Cluster/
Central Gateway Module/
Inside Rear View Mirror/
Overhead Console Module
Ignition
F25 Heating, Ventilation, and Air Conditioning Ignition/
Heating, Ventilation, and
Air Conditioning Auxiliary
F26 USB Ports/Special Equipment Option Retained
Accessory Power
F27 Accessory Power Outlet/ Retained Accessory Power
F28 Accessory Power Outlet/ Battery
F30 Sensing and Diagnostic Module/Parking Brake
F31 Body Control Module 4 Fuses
Usage
F32 Special Equipment Option/ Data Link Connection
F33 Body Control Module 8
F34 Cargo Lamp
F40 CGM –Central Gateway
Module
F41 Infotainment 1
F42 TCP –Telematics
Connectivity Platform
F43 –
F44 –
F45 Body Control Module 2
F46 Heating, Ventilation, and Air Conditioning/Battery 1
F47 Instrument Panel Cluster/ Battery
F48 Transmission Control Module
F49 Body Control Module 1 F50 –
F51 Battery 1
F52 Battery 2

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 337
FusesUsage
F53 –
F54 Sunroof F55 Driver Power Seat
F56 DC DC TRANS 1 F57 DC DC TRANS 2
F58 Infotainment 2
Circuit
Breakers Usage
1 Accessory Power Outlet 2
2 Accessory Power Outlet 1/ Cigarette Lighter
3 –
4 –
Relays Usage
K1 Run/Crank
K2 Retained Accessory Power/ Accessory 1
K4 –
K5 –Wheels and Tires
Tires
Every new GM vehicle has high-quality
tires made by a leading tire
manufacturer. See the warranty manual
for information regarding the tire
warranty and where to get service. For
additional information refer to the tire
manufacturer.
{Warning
.Poorly maintained and improperly
used tires are dangerous.
.Overloading the tires can cause
overheating as a result of too
much flexing. There could be a
blowout and a serious crash. See
Vehicle Load Limits 0215.
.Underinflated tires pose the same
danger as overloaded tires. The
resulting crash could cause serious
injury. Check all tires frequently to
(Continued)
Warning (Continued)
maintain the recommended
pressure. Tire pressure should be
checked when the tires are cold.
.Overinflated tires are more likely
to be cut, punctured, or broken by
a sudden impact —such as when
hitting a pothole. Keep tires at the
recommended pressure.
.Worn or old tires can cause a
crash. If the tread is badly worn,
replace them.
.Replace any tires that have been
damaged by impacts with
potholes, curbs, etc.
.Improperly repaired tires can cause
a crash. Only your dealer or an
authorized tire service center
should repair, replace, dismount,
and mount the tires.
(Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
338 Vehicle Care
Warning (Continued)
.Do not spin the tires in excess of
56 km/h (35 mph) on slippery
surfaces such as snow, mud, ice,
etc. Excessive spinning may cause
the tires to explode.
All-Season Tires
This vehicle may come with all-season tires.
These tires are designed to provide good
overall performance on most road surfaces
and weather conditions. Original equipment
tires designed to GM's specific tire
performance criteria have a TPC specification
code molded onto the sidewall. Original
equipment all-season tires can be identified
by the last two characters of this TPC code,
which will be“MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected. All-season tires
provide adequate performance for most
winter driving conditions, but they may not
offer the same level of traction or
performance as winter tires on snow or
ice-covered roads. See Winter Tires0338.
Winter Tires
This vehicle was not originally equipped
with winter tires. Winter tires are designed
for increased traction on snow and
ice-covered roads. Consider installing winter
tires on the vehicle if frequent driving on ice
or snow covered roads is expected. See your
dealer for details regarding winter tire
availability and proper tire selection. Also,
see Buying New Tires 0352.
With winter tires, there may be decreased
dry road traction, increased road noise, and
shorter tread life. After changing to winter
tires, be alert for changes in vehicle
handling and braking.
If using winter tires:
.Use tires of the same brand and tread
type on all four wheel positions.
.Use only radial ply tires of the same size,
load range, and speed rating as the
original equipment tires.
Winter tires with the same speed rating as
the original equipment tires may not be
available for H, V, W, Y, and ZR speed rated
tires. If winter tires with a lower speed
rating are chosen, never exceed the tire's
maximum speed capability.
All-Terrain Tires
This vehicle may have all-terrain or
mud-terrain tires. These tires provide good
performance on most road surfaces, weather
conditions, and for off-road driving. See
Off-Road Driving 0208.
The tread pattern on these tires may wear
more unevenly than other tires. Consider
rotating the tires more frequently than at
12 000 km (7,500 mi) intervals if irregular
wear is noted when the tires are inspected.
See Tire Inspection 0348.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The example
shows a typical light truck tire sidewall.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 339
Light Truck (LT-Metric) Tire
(1) Tire Size:The tire size code is a
combination of letters and numbers
used to define a particular tire's width,
height, aspect ratio, construction type,
and service description. See the “Tire
Size” illustration later in this section for
more detail.
(2) TPC Spec (Tire Performance Criteria
Specification)
:Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. GM's TPC specifications meet
or exceed all federal safety guidelines. (3) Dual Tire Maximum Load
:
Maximum load that can be carried and
the maximum pressure needed to
support that load when used in a dual
configuration. For information on
recommended tire pressure see
Tire
Pressure 0342 and
Vehicle Load Limits 0215.
(4) DOT (Department of
Transportation)
:The Department of
Transportation (DOT) code indicates that
the tire is in compliance with the U.S.
Department of Transportation Motor
Vehicle Safety Standards.
DOT Tire Date of Manufacture
:The last
four digits of the TIN indicate the tire
manufactured date. The first two digits
represent the week and the last two
digits, the year. For example, the third
week of the year 2020 would have a
4-digit DOT date of 0320. Week 01 is
the first full week (Sunday through
Saturday) of each year.
(5) Tire Identification Number (TIN)
:
The letters and numbers following the
DOT code are the Tire Identification Number (TIN). The TIN shows the
manufacturer and plant code, tire size,
and date the tire was manufactured.
The TIN is molded onto both sides of
the tire, although only one side may
have the date of manufacture.
(6) Tire Ply Material
:The type of cord
and number of plies in the sidewall and
under the tread.
(7) Single Tire Maximum Load
:
Maximum load that can be carried and
the maximum pressure needed to
support that load when used as a
single. For information on
recommended tire pressure see Tire
Pressure 0342 and
Vehicle Load Limits 0215.
Tire Designations
Tire Size
The examples show a typical light truck
tire size.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
340 Vehicle Care
Light Truck (LT-Metric) Tire
(1) Light Truck (LT-Metric) Tire:The
United States version of a metric tire
sizing system. The letters LT as the first
two characters in the tire size mean a
light truck tire engineered to standards
set by the U.S. Tire and Rim
Association.
(2) Tire Width
:The 3-digit number
indicates the tire section width in
millimeters from sidewall to sidewall.
(3) Aspect Ratio
:A 2-digit number that
indicates the tire height-to-width
measurements. For example, if the tire
size aspect ratio is 75, as shown in
item (3) of the light truck (LT-Metric)
tire illustration, it would mean that the
tire's sidewall is 75 percent as high as it
is wide. (4) Construction Code
:A letter code is
used to indicate the type of ply
construction in the tire. The letter R
means radial ply construction; the
letter D means diagonal or bias ply
construction.
(5) Rim Diameter
:Diameter of the
wheel in inches.
(6) Load Range
:Load Range.
(7) Service Description
:The service
description indicates the load index and
speed rating of a tire. If two numbers
are given as in the example, 120/116,
then this represents the load index for
single versus dual wheel usage (single/
dual). The speed rating is the maximum
speed a tire is certified to carry a load.
Tire Terminology and Definitions
Air Pressure:The amount of air inside
the tire pressing outward on each
square inch of the tire. Air pressure is
expressed in kPa (kilopascal) or psi
(pounds per square inch).
Aspect Ratio
:The relationship of a
tire's height to its width. Belt
:A rubber coated layer of cords
that is located between the plies and
the tread. Cords may be made from
steel or other reinforcing materials.
Bead
:The tire bead contains steel
wires wrapped by steel cords that hold
the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which
the plies are laid at alternate angles
less than 90 degrees to the centerline
of the tread.
Cold Tire Pressure
:The amount of air
pressure in a tire, measured in kPa
(kilopascal) or psi (pounds per square
inch) before a tire has built up heat
from driving. See Tire Pressure0342.
DOT Markings
:A code molded into the
sidewall of a tire signifying that the tire
is in compliance with the U.S.
Department of Transportation (DOT)
Motor Vehicle Safety Standards. The
DOT code includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also identify the
tire manufacturer, production plant,
brand, and date of production.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 341
GVWR:Gross Vehicle Weight Rating.
See Vehicle Load Limits 0215.
GAWR FRT
:Gross Axle Weight Rating
for the front axle. See Vehicle Load
Limits 0215.
GAWR RR
:Gross Axle Weight Rating
for the rear axle. See Vehicle Load
Limits 0215.
Intended Outboard Sidewall
:The side
of an asymmetrical tire, that must
always face outward when mounted on
a vehicle.
Kilopascal (kPa)
:The metric unit for air
pressure.
Light Truck (LT-Metric) Tire
:A tire used
on light duty trucks and some
multipurpose passenger vehicles.
Load Index
:An assigned number
ranging from 1 to 279 that corresponds
to the load carrying capacity of a tire.
Maximum Inflation Pressure
:The
maximum air pressure to which a cold
tire can be inflated. The maximum air
pressure is molded onto the sidewall. Maximum Load Rating
:The load rating
for a tire at the maximum permissible
inflation pressure for that tire.
Occupant Distribution
:Designated
seating positions.
Outward Facing Sidewall
:The side of
an asymmetrical tire that has a
particular side that faces outward when
mounted on a vehicle. The side of the
tire that contains a whitewall, bears
white lettering, or bears manufacturer,
brand, and/or model name molding
that is higher or deeper than the same
moldings on the other sidewall of
the tire.
Passenger (P-Metric) Tire
:A tire used
on passenger cars and some light duty
trucks and multipurpose vehicles.
Recommended Inflation Pressure
:
Vehicle manufacturer's recommended
tire inflation pressure as shown on the
tire placard. See Tire Pressure0342 and
Vehicle Load Limits 0215. Radial Ply Tire
:A pneumatic tire in
which the ply cords that extend to the
beads are laid at 90 degrees to the
centerline of the tread.
Rim
:A metal support for a tire and
upon which the tire beads are seated.
Sidewall
:The portion of a tire between
the tread and the bead.
Speed Rating
:An alphanumeric code
assigned to a tire indicating the
maximum speed at which a tire can
operate.
Traction
:The friction between the tire
and the road surface. The amount of
grip provided.
Tread
:The portion of a tire that comes
into contact with the road.
Treadwear Indicators
:Narrow bands,
sometimes called wear bars, that show
across the tread of a tire when only
1.6 mm (1/16 in) of tread remains. See
When It Is Time for New Tires 0351.