check engine light GMC SIERRA 2023 User Guide

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 211
{Warning
Driving on frozen lakes, ponds, or rivers
can be dangerous. Ice conditions vary
greatly and the vehicle could fall through
the ice; you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only
shallow water, it can still wash away the
ground from under your tires. Traction
could be lost, and the vehicle could roll
over. Do not drive through rushing water.
Caution
Do not drive through standing water if it
is deep enough to cover the wheel hubs,
axles, or exhaust pipe. Deep water can
damage the axle and other vehicle parts.If the standing water is not too deep, drive
through it slowly. At faster speeds, water
can get into the engine and cause it to stall.
Stalling can occur if the exhaust pipe is
under water. Do not turn off the ignition
when driving through water. If the exhaust
pipe is under water, the engine will not
start. When going through water, the brakes
get wet and it may take longer to stop. See
“Driving on Wet Roads”
later in this section.
After Off-Road Driving
Remove any brush or debris that has
collected on the underbody or chassis,
or under the hood. These accumulations can
be a fire hazard. Reinstall underbody air
deflector and air dam if removed.
After operation in mud or sand, have the
brake linings cleaned and checked. These
substances can cause glazing and uneven
braking. Check the body structure, driveline,
steering, suspension, wheels, tires, and
exhaust system for damage and check the
fuel lines and cooling system for any
leakage.
More frequent maintenance service is
required. See theMaintenance Schedule
0 385.
Driving on Wet Roads
Rain and wet roads can reduce vehicle
traction and affect your ability to stop and
accelerate. Always drive slower in these
types of driving conditions and avoid driving
through large puddles and deep-standing or
flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick stop
and could cause pulling to one side. You
could lose control of the vehicle.
After driving through a large puddle of
water or a car/vehicle wash, lightly apply
the brake pedal until the brakes work
normally.
Flowing or rushing water creates strong
forces. Driving through flowing water
could cause the vehicle to be carried
away. If this happens, you and other
vehicle occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive through
flowing water.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 241
HSA is available when the vehicle is facing
uphill in a forward gear, or when facing
downhill in R (Reverse). The vehicle must
come to a complete stop on a grade for HSA
to activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control System
(TCS) and StabiliTrak/Electronic Stability
Control (ESC) system. These systems help
limit wheel spin and assist the driver in
maintaining control, especially on slippery
road conditions.
TCS activates if it senses any of the drive
wheels are spinning or beginning to lose
traction. When this happens, TCS applies the
brakes to the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actually
traveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keepingthe vehicle on the intended path. Trailer
Sway Control (TSC) is also on automatically
when the vehicle is started. See
Trailer Sway
Control (TSC) 0285.
If cruise control is being used and traction
control or StabiliTrak/ESC begins to limit
wheel spin, cruise control will disengage.
Cruise control may be turned back on when
road conditions allow.
Both systems come on automatically when
the vehicle is started and begins to move.
The systems may be heard or felt while
they are operating or while performing
diagnostic checks. This is normal and does
not mean there is a problem with the
vehicle.
It is recommended to leave both systems on
for normal driving conditions, but it may be
necessary to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow. See If the
Vehicle Is Stuck 0214 and “Turning the
Systems Off and On” later in this section.
When the transfer case (if equipped) is in
Four-Wheel Drive Low, the stability system
is automatically disabled,
gcomes on, and
the appropriate message will appear on the Driver Information Center (DIC). Both
traction control and StabiliTrak/ESC are
automatically disabled in this condition.
The indicator light for both systems is in the
instrument cluster. This light will:
.Flash when TCS is limiting wheel spin.
.Flash when StabiliTrak/ESC is activated.
.Turn on and stay on when either system
is not working.
If either system fails to turn on or to
activate, a message displays in the Driver
Information Center (DIC), and
dcomes on
and stays on to indicate that the system is
inactive and is not assisting the driver in
maintaining control. The vehicle is safe to
drive, but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 267
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.(Continued)
Warning (Continued)
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Turn the fuel cap counterclockwise to
remove. Fully insert and latch the fill nozzle,
begin fueling. For models with dual fuel
tanks, the fuel gauge shows an average of
both tanks. When refueling, refuel the
primary front tank first, then add fuel to the
auxiliary rear tank.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires. Be careful not to spill fuel. Wait five seconds
after you have finished pumping before
removing the fill nozzle. Clean fuel from
painted surfaces as soon as possible. See
Exterior Care
0374. Reinstall the cap by
turning it clockwise until it clicks.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, get the right
type of cap from your dealer. The wrong
type of fuel cap may not fit properly,
may turn on the malfunction indicator
lamp, and could damage the fuel system
and emissions system. See Malfunction
Indicator Lamp (Check Engine Light)
0 120.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 285
.There is an electrical fault in the wiring to
the trailer brakes. This message will
continue as long as there is an electrical
fault in the trailer wiring. This message
will also turn off if it is acknowledged.
To determine whether the electrical fault is
on the vehicle side or trailer side of the
trailer wiring harness connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the vehicle off.
3. Wait 10 seconds, then turn the vehicle back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING message only
reappears when connecting the trailer wiring
harness to the vehicle, the electrical fault is
on the trailer side.
TRAILER BRAKES DISABLED SERVICE
REQUIRED: This message will display when
there is a problem with the ITBC system.
If this message continues over multiple
restarts, have the vehicle serviced. If either the CHECK TRAILER WIRING, TRAILER
BRAKES DISABLED SERVICE REQUIRED,
SERVICE TRAILER BRAKES, HOLD LAST KNOWN
GAIN, or REDUCED TRAILER BRAKING
message displays while driving, the ITBC
system may not be fully functional or may
not function at all. When traffic conditions
allow, carefully pull the vehicle over to the
side of the road and turn the vehicle off.
Check the wiring connection to the trailer
and turn the vehicle back on. If either of
these messages continue, either the vehicle
or trailer needs service.
A GM dealer may be able to diagnose and
repair problems with the trailer. However,
any diagnosis and repair of the trailer is not
covered under the vehicle warranty. Contact
your trailer dealer for assistance with trailer
repairs and trailer warranty information.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.If equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reduce
vehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0
241.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 297
Theft Alert
A theft alert can be set if a trailer is
connected and the alert is enabled. When
the trailer is disconnected and the vehicle is
off, an alarm will sound.
Touch Theft Alert in Settings to view the
Theft Alert settings page. These alerts are
based on the Trailer Profile, so the settings
for each Trailer Profile must be turned on or
off. Touch a profile to view more
information or adjust the setting for that
profile.
This setting will be off by default for each
Trailer Profile, including the Guest Trailer
Profile.
A smartphone will receive a notification that
the trailer related to the selected Trailer
Profile is disconnected from the vehicle,
if the setting is on for the active Trailer
Profile, the vehicle has an OnStar or
connected service plan and the smartphone
number has been added to the account for
this notification.
If the setting is turned off for a given Trailer
Profile, the smartphone will not receive this
security notification even if the Trailer
Profile is active.
Tow/Haul Mode Reminder
This is a reminder to turn on the Tow/Haul
Mode when towing a trailer. SeeTow/Haul
Mode 0234.
Touch Tow/Haul Mode Reminder in Settings
to view the Tow/Haul Mode Reminder
settings page. These alerts are based on the
Trailer Profile, so the settings for each
Trailer Profile must be turned on or off.
Touch a profile to view more information or
to adjust the setting for that profile.
This setting will default to OFF for each
Trailer Profile, including the Guest Trailer
Profile.
If Tow/Haul Mode is off and this setting is
on for a Trailer Profile, each time the vehicle
is turned on a reminder will appear to turn
on Tow/Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this setting is
on for a Trailer Profile, the reminder will not
appear when the Trailer Profile is active.
Trailer Length Indicator
Touch Trailer Length Indicator to view the
Trailer Length Indicator settings page. If this
setting is ON a guideline is displayed in the side mirror camera view to indicate the rear
of the attached trailer. If this setting is OFF
the guideline will not be displayed.
This setting will default to OFF if the trailer
length indicator feature is not set up. See
"Towing Assistance" for details on the setup.
Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. See
Malfunction
Indicator Lamp (Check Engine Light) 0120
. A device connected to the DLC —such
as an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/18/22
Vehicle Care 301
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 302
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 302
Accessories and Modifications . . . . . . . . . 302
Vehicle Checks
Doing Your Own Service Work . . . . . . . . 303
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Engine Compartment Overview . . . . . . . . 305
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Engine Oil Life System . . . . . . . . . . . . . . . . 308
Automatic Transmission Fluid . . . . . . . . . 309
Engine Air Filter Life System . . . . . . . . . . 309
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 310
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 311
Engine Overheating . . . . . . . . . . . . . . . . . . . . 313
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . 315
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Power Steering Fluid . . . . . . . . . . . . . . . . . . . 315
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Brake Pad Life System . . . . . . . . . . . . . . . . . 317
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
Battery - North America . . . . . . . . . . . . . . . 319
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 321
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Noise Control System . . . . . . . . . . . . . . . . . . 321
Automatic Transmission Shift Lock
Control Function Check (Mechanical
Shifter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Wiper Blade Replacement . . . . . . . . . . . . . 323
Glass Replacement . . . . . . . . . . . . . . . . . . . . . 323
Windshield Replacement . . . . . . . . . . . . . . 324
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 325
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 325
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 325
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 325
Taillamps, Turn Signal, Stoplamps, and Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . 326
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . 327
License Plate Lamp . . . . . . . . . . . . . . . . . . . . 327
Electrical System
Electrical System Overload . . . . . . . . . . . . . 327
Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Engine Compartment Fuse Block . . . . . . 329 Instrument Panel Fuse Block (Left) . . . . . 333
Instrument Panel Fuse Block (Right) . . . 334
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 338
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 338
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 339
Tire Terminology and Definitions . . . . . 340
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Tire Pressure Monitor System . . . . . . . . . 343
Tire Pressure Monitor Operation . . . . . . 344
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 348
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 349
When It Is Time for New Tires . . . . . . . . . 351
Buying New Tires . . . . . . . . . . . . . . . . . . . . . . 352
Different Size Tires and Wheels . . . . . . . . 353
Uniform Tire Quality Grading . . . . . . . . . . 353
Wheel Alignment and Tire Balance . . . . 354
Wheel Replacement . . . . . . . . . . . . . . . . . . . 354
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 356
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 367
Jump Starting
Jump Starting - North America . . . . . . . . 367

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 - 5/18/22
Vehicle Care 377
detergent. To restore the original
appearance, apply the bedliner conditioner
available through your dealer.
CarbonPro Box Care
Caution
To prevent surface damage to the pickup
box, rinse chemical spills quickly, never
use alcohol wipes to clean, and avoid
scraping the surface.
If equipped with a CarbonPro Pickup Box,
use the following instructions for cleaning:
.Clean the box periodically by washing off
the loose dirt with water and a mild
detergent.
.Promptly rinse the bed surface following
a chemical spill to avoid permanent
damage.
.Use a dry rag to remove oil.
Cleaning Exterior Lamps/Lenses,
Emblems, Decals and Stripes
Use only lukewarm or cold water, a soft
cloth, and a car washing soap to clean
exterior lamps, lenses, emblems, decals and
stripes. Follow instructions under "Washing
the Vehicle" previously in this section. Lamp covers are made of plastic, and some
have a UV protective coating. Do not clean
or wipe them while they are dry.
Do not use any of the following on lamp
covers:
.Abrasive or caustic agents.
.Washer fluids and other cleaning agents
in higher concentrations than suggested
by the manufacturer.
.Solvents, alcohols, fuels, or other harsh
cleaners.
.Ice scrapers or other hard items.
.Aftermarket appearance caps or covers
while the lamps are illuminated, due to
excessive heat generated.
Caution
Failure to clean lamps properly can cause
damage to the lamp cover that would
not be covered by the vehicle warranty.
Caution
Using wax on low gloss black finish
stripes can increase the gloss level and
create a non-uniform finish. Clean low
gloss stripes with soap and water only.
Air Intakes
Clear debris from the air intakes, between
the hood and windshield, when washing the
vehicle.
Shutter System
The vehicle may have a shutter system
designed to help improve fuel economy.
Keep the shutter system clear of debris,
snow and ice. If the check engine light is
activated, please check to see if the shutter
system is clear of debris, snow or ice.
Windshield and Wiper Blades
Clean the outside of the windshield with
glass cleaner.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Service and Maintenance 387
* Footnote: Under extreme driving
conditions listed above, it may be
necessary to replace your spark plugs at
more frequent intervals. For further
assistance in determining the most
suitable service maintenance intervals for
your vehicle, please contact your
authorized GM Dealer.
Extreme service is for vehicles mainly
driven off-road in four-wheel drive or used
in farming, mining, forestry, or snow
plowing.
Additional Required Services—Severe
Service
Every 40 000 km (25,000 mi)
.Change transfer case fluid, if equipped
with 4WD. 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
transfer case fluid. Contaminated fluid will
decrease the life of the transfer case and/
or axles and should be replaced. Every 72 000 km (45,000 mi)
.Change automatic transmission fluid and
filter.
Owner Checks and Services
Every Five Years
.Replace brake fluid.
Every Seven Years
.Replace Air Conditioning Desiccant every
seven years. The air conditioning system
requires maintenance every seven years.
This service requires replacement of the
desiccant to help the longevity and
efficient operation of the air conditioning
system. This service can be complex. See
your dealer.
Multi-Point Vehicle
Inspection (MPVI)
A Multi Point Vehicle Inspection (MPVI)
completed by a GM dealer technician is a
maintenance assessment of your vehicle.
The benefit of the MPVI is to identify and
inform the customer of service items that
require immediate attention and those that
may require attention in the future. The technician will perform the following
checks on your vehicle. For a complete list
of checks, inspections, and services, see your
dealer.
Some items may not apply to your vehicle
and/or region.
Diagnostics
.OnStar active, if equipped
.Service history/recall check
Engine Oil and Filter
.Engine oil
.Oil life monitor
‐
Reset oil life monitor
Exterior Lights
.Visual inspection
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and connections