ECU GMC SIERRA 2024 Repair Manual

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
370 Vehicle Care
Rear Position
{Warning
If equipped, use a jack lift head adapter
on the front jacking position only. Never
use the adapter on the rear jacking
position. The adapter is not designed to
function on the rear lift point. Using the
adapter on the rear jacking position could
result in damage to the vehicle or
personal injury.
5. If the flat tire is on the rear of the vehicle, position the jack under the rear
axle between the spring anchor and the
shock absorber bracket. If a snow plow has been added to the
front of the vehicle, lower the snow
plow fully before raising the vehicle.
Make sure that the jack head is
positioned so that the rear axle is resting
securely between the grooves that are
on the jack head.
{Warning
Getting under a vehicle when it is lifted
on a jack is dangerous. If the vehicle slips
off the jack, you could be badly injured
or killed. Never get under a vehicle when
it is supported only by a jack.
{Warning
Raising the vehicle with the jack
improperly positioned can damage the
vehicle and even make the vehicle fall. To
help avoid personal injury and vehicle
damage, be sure to fit the jack lift head
into the proper location before raising
the vehicle.
{Warning
The jack has a feature to limit its travel
to prevent overextension. When the
height limit is reached, an increase in
resistance if felt when attempting to
raise the jack farther. Raising the jack
past the height limit can damage the jack
pin and cause the jack to lock into an
overextended position or not lower fully.
Do not attempt to force the jack higher
once the height limit is reached.
6. Turn the wheel wrench clockwise to raise the vehicle. Raise the vehicle far enough
off the ground so there is enough room
for the spare tire to fit under the
wheel well.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
372 Vehicle Care
{Warning
Wheel nuts that are improperly or
incorrectly tightened can cause the
wheels to become loose or come off. The
wheel nuts should be tightened with a
torque wrench to the proper torque
specification after replacing. Follow the
torque specification supplied by the
aftermarket manufacturer when using
accessory locking wheel nuts. See
Capacities and Specifications0402 for
original equipment wheel nut torque
specifications.
Caution
Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To
avoid expensive brake repairs, evenly
tighten the wheel nuts in the proper
sequence and to the proper torque
specification. See Capacities and
Specifications 0402 for the wheel nut
torque specification.
13. Tighten the nuts firmly in a crisscross sequence, as shown, by turning the
wheel wrench clockwise.
For vehicles with dual wheels, have a
technician check the wheel nut tightness of
all wheels with a torque wrench after the
first 160, 1 600 and 10 000 km (100, 1,000
and 6,000 mi). Repeat this service whenever
you have a tire removed or serviced. See
Capacities and Specifications 0402.
When reinstalling the regular wheel and tire,
also reinstall either the center cap,
or bolt-on hub cap, depending on what the
vehicle is equipped with. For center caps,
place the cap on the wheel and tap it into
place until it seats flush with the wheel. The
cap only goes on one way. Be sure to line
up the tab on the center cap with the
indentation on the wheel. For bolt-on hub caps, align the plastic nut caps with the
wheel nuts and then tighten by hand. Then
use the wheel wrench to tighten.
Storing a Flat or Spare Tire and Tools
{Warning
Storing a jack, a tire, or other equipment
in the passenger compartment of the
vehicle could cause injury. In a sudden
stop or collision, loose equipment could
strike someone. Store all these in the
proper place.
{Warning
Failure to follow these tire storage
instructions carefully could result in
personal injury or property damage if the
hoist cable fails or if the tire comes loose.
Make sure the tire is stored securely
before driving.
Caution
Storing an aluminum wheel with a flat
tire under your vehicle for an extended
period of time or with the valve stem
(Continued)

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
374 Vehicle Care
4. Attach the wheel wrench (7) andextensions (6) together, as shown.
Caution
Use of an air wrench or other power
tools with the hoist mechanism is not
recommended and could damage the
system. Use only the tools supplied with
the hoist mechanism.
5. Insert the hoist end (10) through thehole (9) in the rear bumper and onto the
hoist shaft.
Do not use the chiseled end of the wheel
wrench.
6. Raise the tire part way upward. Make sure the retainer is seated in the wheel
opening.
7. If equipped with a spare tire cable, orientthe cable by rotating the spare tire so
that the cable is by the frame
attachment location. 8. Raise the tire fully against the underside
of the vehicle by turning the wheel
wrench clockwise until you hear two
clicks or feel it skip twice. You cannot
overtighten the cable.
9. Make sure the tire is stored securely.Push, pull, and then try to turn the tire.
If the tire moves, use the wheel wrench
to tighten the cable.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Vehicle Care 379
11. Start the vehicle with the good batteryand run the engine for a while.
12. Try to start the vehicle that had the dead battery. If it will not start after a
few tries, it probably needs service.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle and
removing the jumper cables, allow it to idle
for several minutes.
Towing the Vehicle
Transporting a Disabled Vehicle
Caution
Incorrectly transporting a disabled vehicle
may cause damage to the vehicle. Use
proper tire straps to secure the vehicle to
the flatbed tow truck. Do not strap or
hook to any frame, underbody,
or suspension component not specified
below. Do not move vehicles with drive
axle tires on the ground. Damage is not
covered by the vehicle warranty.
Caution
The vehicle may be equipped with an
electric parking brake and/or a
mechanical transmission range select
shifter. In the event of a loss of 12-volt
battery power, the electric parking brake
cannot be released, and the vehicle
cannot be shifted to N (Neutral). Tire
skates or dollies must be used under the
non-rolling tires to prevent damage while
loading/unloading the vehicle. Dragging
the vehicle will cause damage not
covered by the vehicle warranty.
Caution
The vehicle may be equipped with a tow
eye. Improper use of the tow eye may
cause damage to the vehicle and is not
covered by the vehicle warranty.
If equipped, use the tow eye to load the
vehicle onto a flatbed tow truck from a
flat road surface, or to move the vehicle
a very short distance at a walking pace.
The tow eye is not designed for off-road
(Continued)
Caution (Continued)
recovery. The vehicle must be in
N (Neutral) with the electric parking
brake released when using the tow eye.
Contact a professional towing service if the
disabled vehicle must be transported. GM
recommends a flatbed tow truck to
transport a disabled vehicle. Use ramps to
help reduce approach angles, if necessary.
If equipped, a tow eye may be located near
the spare tire or emergency jack. Do not use
the tow eye to pull the vehicle from the
snow, mud, sand, or ditch. Tow eye threads
may have right or left-hand threads. Use
caution when installing or removing the
tow eye.
The vehicle must be in N (Neutral) and the
electric parking brake must be released
when loading the vehicle onto a flatbed tow
truck.
.If the 12-volt battery is dead and/or
electric parking brake is not released, the
vehicle will not move. Try to jump start
the vehicle with a known good 12-volt
battery, shift the car into N (Neutral), and
release the electric parking brake. Refer to
Jump Starting - North America 0376.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Vehicle Care 381
Dinghy Towing (Two-Wheel Drive)
Caution
If a two-wheel-drive vehicle is towed with
the rear wheels on the ground, the
transmission could be damaged. The
repairs would not be covered by the
vehicle warranty. Never tow the vehicle
with the rear wheels on the ground.
Two-wheel-drive vehicles should not be
towed with all four wheels on the ground.
Dinghy Towing (Four-Wheel Drive)
Only dinghy tow four-wheel-drive vehicles
with a two-speed transfer case that have an
N (Neutral) and a 4
n(Four-Wheel Drive Low)
setting.
{Warning
Shifting a four-wheel-drive vehicle's
transfer case into N (Neutral) can allow
the vehicle to move even if the
transmission is in P (Park). You or others
could be injured. Set the parking brake
and use wheel blocks before shifting the
transfer case to N (Neutral). To dinghy tow:
1. Position the vehicle being towed behind the tow vehicle, facing forward and on a
level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into N (Neutral)” under
Four-Wheel Drive 0228.
5. With the engine running, release the parking 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. Turn the vehicle off. Disregard the Shift to P (Park) DIC message. See Ignition
Positions 0216.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
382 Vehicle Care
{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 0327.
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. Keep the remote key outside of the vehicle and manually lock the doors.
Access the vehicle by using the key in
the door lock. See Door Locks022. Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle:
1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Reconnect the negative (–) battery. See Battery - North America 0327.
3. Turn on the vehicle. 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 0216.
4. Set the parking brake. See Electric
Parking Brake 0234.
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 0125.
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 vehicle.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets.
The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.
Dolly Towing

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
392 Vehicle Care
.Use the floor mat/liner insert with the
correct side up. Do not turn it over.
.Do not place anything on top of the
driver side floor mat/liner.
.Use only a single floor mat/liner on the
driver side.
.Do not place one floor mat/liner on top
of another.
Removing and Replacing the Floor Mats/
Liners
Pull up on the rear of the driver side floor
mat/liner to unlock each retainer and
remove.
Reinstall by lining up the floor mat/liner
retainer openings over the carpet retainers
and snapping into position.
Make sure the floor mat/liner is properly
secured in place.
Verify the floor mat/liner does not interfere
with the pedals.
Removing and Replacing the Floor Liner
Inserts
Pull up on the edge of the driver side floor
liner insert to unlock each button clip and
remove.
Reinstall by lining up the floor liner insert
button clips over the liner retainers and
snapping into position.Make sure the floor liner insert is properly
secure in place using all button clips.
Verify the floor liner insert does not
interfere with the pedals.
Cleaning Rubber Floor Mats (All-Weather
Mats and Floor Liners)
See
“Vinyl/Rubber” underInterior Care
0 388 for important cleaning information.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Service and Maintenance 395
Additional Required Services–Normal
Service
Every 12 000 km (7,500 mi)
.Check engine oil level and oil
life percentage. If needed, change engine
oil and filter, and reset oil life system. Or
when the CHANGE ENGINE OIL SOON
message displays, have the engine oil
and filter changed within the next
1 000 km/600 mi. If driven under the best
conditions, the engine oil life system may
not indicate the need for vehicle service
for up to a year. The engine oil and filter
must be changed at least once a year and
the oil life system must be reset. Your
trained dealer technician can perform this
work. If the engine oil life system is reset
accidentally, service the vehicle within
5 000 km/3,000 mi since the last service.
Reset the oil life system when the oil is
changed. See Engine Oil Life System
0 316.
.When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the
engine air filter should be replaced at the
earliest convenience. Reset the engine air filter life system after the engine air filter
is replaced. See
Engine Air Filter Life
System 0317.
Every 36 000 km (22,500 mi)
.Replace passenger compartment air filter.
Or every 24 months, whichever comes
first. More frequent passenger
compartment air filter replacement may
be needed if driving in areas with heavy
traffic, poor air quality, high dust levels,
or environmental allergens. Passenger
compartment air filter replacement may
also be needed if there is reduced airflow,
window fogging, or odors. Your GM
dealer can help determine when to
replace the filter.
Every 80 500 km (50,000 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 156 000 km (97,500 mi)
.Replace spark plugs. Inspect spark plug
wires and/or boots. Every 161 000 km (100,000 mi)
.Replace hood and/or body lift support gas
struts. Or every 10 years, whichever
comes first. See
Gas Strut(s)0332.
Every 240 000 km (150,000 mi)
.Drain and fill engine cooling system. Or
every six years, whichever comes first.
See Cooling System 0319.
Severe Conditions Requiring More
Frequent Maintenance*
.Public service, military, or commercial use
vehicles to include the following:
‐ Ambulances, police cars, and
emergency rescue vehicles.
‐ Civilian vehicles such as light duty
pick-up trucks, SUVs, and passenger
cars that are used in military
applications.
‐ Recovery vehicles such as tow trucks
and flatbed single vehicle carriers or
any vehicle that is consistently used in
towing trailers or other loads.
‐ High use commercial vehicles such as
courier delivery vehicles, private
security patrol vehicles, or any vehicles
that operate on a 24-hour basis.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Service and Maintenance 397
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and connections
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 0383.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16908340) - 2024 - CRC - 12/7/22
Customer Information 405
Customer Information
Customer Information
Customer Satisfaction Procedure . . . . . . 405
Customer Assistance Offices . . . . . . . . . . . 407
Customer Assistance for Text Telephone(TTY) Users . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Online Account . . . . . . . . . . . . . . . . . . . . . . . . 407
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408
Roadside Assistance Program . . . . . . . . . 408
Scheduling Service Appointments . . . . . . 410
Courtesy Transportation Program . . . . . 410
Collision Damage Repair . . . . . . . . . . . . . . . 411
Publication Ordering Information . . . . . . 413
Radio Frequency Statement . . . . . . . . . . . . 413
Reporting Safety Defects
Reporting Safety Defects to the United States Government . . . . . . . . . . . . . . . . . . 414
Reporting Safety Defects to the Canadian Government . . . . . . . . . . . . . . . 414
Reporting Safety Defects to General Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
Vehicle Data Recording and Privacy
Vehicle Data Recording and Privacy . . . . 415
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Event Data Recorders . . . . . . . . . . . . . . . . . . 415
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416
Infotainment System . . . . . . . . . . . . . . . . . . 416Customer Information
Customer Satisfaction Procedure
Your satisfaction and goodwill are important
to your dealer and to GMC. Normally, any
concerns with the sales transaction or the
operation of the vehicle will be resolved by
your dealer's sales or service departments.
Sometimes, however, despite the best
intentions of all concerned,
misunderstandings can occur. If your concern
has not been resolved to your satisfaction,
the following steps should be taken:
STEP ONE : Discuss your concern with a
member of dealership management.
Normally, concerns can be quickly resolved
at that level. If the matter has already been
reviewed with the sales, service, or parts
manager, contact the owner of your
dealership or the general manager.
STEP TWO : If after contacting a member of
dealership management, it appears your
concern cannot be resolved by your
dealership without further help, in the U.S.,
call 1-800-462-8782. In Canada, call General
Motors of Canada Customer Care Centre at
1-800-263-3777 (English), or 1-800-263-7854
(French).