
GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 303
Damage to suspension components caused
by modifying vehicle height outside of
factory settings will not be covered by the
vehicle warranty.
Damage to vehicle components resulting
from modifications or the installation or use
of non-GM certified parts, including control
module or software modifications, is not
covered under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to complement
and function with other systems on the
vehicle. See your dealer to accessorize the
vehicle using genuine GM Accessories
installed by a dealer technician.
Also, seeAdding Equipment to the
Airbag-Equipped Vehicle 074.Vehicle Checks
Doing Your Own Service Work
{Warning
It can be dangerous to work on your
vehicle if you do not have the proper
knowledge, service manual, tools,
or parts. Always follow owner’s manual
procedures and consult the service
manual for your vehicle before doing any
service work.
If doing some of your own service work, use
the proper service manual. It tells you much
more about how to service the vehicle than
this manual can. To order the proper service
manual, see Publication Ordering
Information 0404.
This vehicle has an airbag system. Before
attempting to do your own service work,
see Servicing the Airbag-Equipped Vehicle
0 73. If equipped with remote vehicle start, open
the hood before performing any service
work to prevent remote starting the vehicle
accidentally. See
Remote Vehicle Start 022.
Keep a record with all parts receipts and list
the mileage and the date of any service
work performed. See Maintenance Records
0 391.
Caution
Even small amounts of contamination can
cause damage to vehicle systems. Do not
allow contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
Turn the vehicle off before opening the
hood. If the engine is running with the
hood open, you or others could be
injured.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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308 Vehicle Care
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for good
performance and engine protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain elements
that can be unhealthy for your skin and
could even cause cancer. Do not let used oil
stay on your skin for very long. Clean your
skin and nails with soap and water, or a
good hand cleaner. Wash or properly
dispose of clothing or rags containing used
engine oil. See the manufacturer's warnings
about the use and disposal of oil products.
Used oil can be a threat to the environment.
If you change your own oil, be sure to drain
all the oil from the filter before disposal.
Never dispose of oil by putting it in the
trash or pouring it on the ground, into
sewers, or into streams or bodies of water.
Recycle it by taking it to a place that
collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system that
indicates when to change the engine oil and
filter. This is based on a combination of
factors which include engine revolutions,
engine temperature, and miles driven. Based
on driving conditions, the mileage at which
an oil change is indicated can vary
considerably. For the oil life system to work
properly, the system must be reset every
time the oil is changed.
On some vehicles, when the system has
calculated that oil life has been diminished,
a CHANGE ENGINE OIL SOON message comes
on to indicate that an oil change is
necessary. Change the oil as soon as
possible within the next 1 000 km (600 mi).
It is possible that, if driving under the best
conditions, the oil life system might indicate
that an oil change is not necessary for up to
a year. The engine oil and filter must be
changed at least once a year and, at this
time, the system must be reset. For vehicles
without the CHANGE ENGINE OIL SOON
message, an oil change is needed when the
REMAINING OIL LIFE percentage is near 0%.
Your dealer has trained service people whowill perform this work and reset the system.
It is also important to check the oil regularly
over the course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally, the
oil must be changed at 5 000 km (3,000 mi)
since the last oil change. Remember to reset
the oil life system whenever the oil is
changed.
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is
changed so that the system can calculate
the next engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To reset the
engine oil life system:
1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0128 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0130.
2. Press the thumbwheel on the steering wheel, or the trip odometer reset stem if
the vehicle does not have DIC controls,
for several seconds. When the
confirmation message displays, select
YES. The oil life will change to 100%.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 309
The oil life system can also be reset as
follows:1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0128 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0130.
2. Fully press the accelerator pedal slowly three times within five seconds.
3. If the display changes to 100%, the system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See
Publication Ordering
Information 0404.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0389.
Change the fluid and filter at the scheduled
maintenance intervals listed in Maintenance
Schedule 0385. Be sure to use the
transmission fluid listed in Recommended
Fluids and Lubricants 0389.
Engine Air Filter Life System
This feature provides the engine air filter’s
remaining life and best timing for a change.
The timing to change and engine air filter
depends on driving and environmental
conditions.
When to Change Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0128 or
Driver Information Center (DIC) (Midlevel
and Uplevel) 0130.
3. Press
Ton the steering wheel, or press
the trip odometer reset stem if the
vehicle does not have the DIC controls,
to move to the Reset/Disable display

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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Vehicle Care 321
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer toMaintenance Schedule 0385 to
determine when to check the lubricant.
1. Fill Plug
2. Drain Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the fill
plug (1) hole, located on the transfer case,
some lubricant will need to be added. Add enough lubricant to raise the level to the
bottom of the fill plug (1) hole. Use care not
to overtighten the plug.
When to Change Lubricant
Refer to
Maintenance Schedule 0385 to
determine how often to change the
lubricant.
What to Use
Refer to Recommended Fluids and Lubricants
0 389 to determine what kind of lubricant
to use.
Front Axle
When to Check Lubricant
It is not necessary to regularly check the
front axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
Rear Axle
When to Check Lubricant
It is not necessary to regularly check the
rear axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.
Noise Control System
NOISE EMISSIONS WARRANTY
General Motors LLC, warrants to the first
person who purchases this vehicle for
purposes other than resale and to each
subsequent purchaser that this vehicle as
manufactured by General Motors LLC, was
designed, built and equipped to conform at
the time it left General Motors LLC’s control
with all applicable U.S. EPA Noise Control
Regulations. This warranty covers this
vehicle as designed, built and equipped by

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
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322 Vehicle Care
General Motors LLC, and is not limited to
any particular part, component or system of
the vehicle manufactured by General Motors
LLC. Defects in design, assembly or in any
part, component or system of the vehicle as
manufactured by General Motors LLC, which,
at the time it left General Motors LLC’s
control, caused noise emissions to exceed
Federal standards, are covered by this
warranty for the life of the vehicle.
TAMPERING WITH NOISE CONTROL
SYSTEM PROHIBITED
Federal law prohibits the following acts or
the causing thereof:1. The removal or rendering inoperative by any person, other than for purposes of
maintenance, repair, or replacement, of
any device or element of design
incorporated into any new vehicle for
the purpose of noise control prior to its
sale or delivery to the ultimate purchaser
or while it is in use; or
2. the use of the vehicle after such device or element of design has been removed
or rendered inoperative by any person. Among those acts presumed to constitute
tampering are the acts listed below.
Insulation:
Removal of the noise shields or any
undercab insulation.
Engine:
Removal or rendering engine speed
governor, if so equipped, inoperative so as
to allow engine speed to exceed
manufacturer specifications.
Modification of the engine control system or
calibration.
Fan and Drive:
.Removal of fan clutch or rendering clutch
inoperative.
.Removal of the fan shroud.
Air Intake:
.Removal of air cleaner silencer.
.Reversing air cleaner cover.
Exhaust:
.Removal of muffler, catalytic converter,
and/or resonator.
.Removal of exhaust pipes and exhaust
pipe clamps.
Automatic Transmission Shift Lock
Control Function Check
(Mechanical Shifter)
{Warning
When you are doing this inspection, the
vehicle could move suddenly. If the
vehicle moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room around the vehicle.
It should be parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the ignition on, but do not start the engine. Without
applying the regular brake, try to move
the shift lever out of P (Park) with
normal effort. If the shift lever moves
out of P (Park), contact your dealer for
service.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 331
FusesUsage
6 –
7 –
8 Fog lamp
9 –
10 –
11 Police upfitter
12 –
13 Washer front
14 Washer rear 15 –
16 –
17 IECL 1
19 DC/AC inverter
20 IECR 2 (LD) / EBCM2 (HD)
21 –
22 IECL 2
24 EBCM 1 25 –
26 – Fuses
Usage
27 Horn
28 –
29 –
30 –
31 –
32 Rear window defogger
33 Heated mirror
34 Parking lamp left 37 –
38 –
39 –
40 Misc ignition 41 Trailer parking lamp
42 Park lamp right
44 –
45 –
46 Engine control module ignition
47 Transmission control module ignition Fuses
Usage
48 –
49 Transmission control module
50 A/C clutch 51 Transfer case control module
52 Front wiper
53 Center high-mounted stop lamp
54 Trailer reverse lamp 55 Trailer back-up lamp
56 SADS 57 TTPM/SBZA
58 Starter motor (LD & HD DSL)
60 Active fuel management 1
61 VES
62 Integrated chassis control module/CVS
63 Trailer battery

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
332 Vehicle Care
FusesUsage
65 Auxiliary underhood electrical center
66 Cooling fan motor left 67 Active fuel management 2
68 –
69 Starter Pinion (LD) / Starter Motor (HD Gas)
71 Cooling fan
72 Cooling fan right/lower
73 Trailer stop/turn lamp left
74 Trailer Interface Module 1
75 DEFC
76 Electric RNG BDS
78 Engine control module
79 Auxiliary battery
80 Cabin cooling pump 81 Trailer stop/turn lamp right Fuses
Usage
82 Trailer Interface Module 2
83 FTZM
84 Trailer brake 85 ENG
86 Engine control module 87 Injector B even
88 O2 B sensor
89 O2 A sensor
90 Injector A odd 91 Engine control module throttle control
92 Cool fan clutch/ Aeroshutter Relays
Usage
5 Headlamp
18 DC/AC inverter
23 Rear window defogger
35 Parking lamp
36 Run/Crank
43 –
59 A/C clutch
64 Starter Motor (LD & HD DSL)
70 Starter Pinion (LD) / Starter Motor (HD Gas)
77 Powertrain

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