2018 GMC SIERRA ECU

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
420 Vehicle Care
Rear Position–All Other Models
For all other models, 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.
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.
7. Remove all the wheel nuts andtake off the flat tire.
{Warning
Rust or dirt on a wheel, or on the
parts to which it is fastened, can
make wheel nuts become loose
after time. The wheel could come
off and cause an accident. When
changing a wheel, remove any
rust or dirt from places where the
wheel attaches to the vehicle. In
an emergency, a cloth or a paper
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
424 Vehicle Care
3. Attach the wheel wrench (7)and extensions (6) together, as
shown.
4. Insert the hoist end (10)
through the hole (9) in the rear
bumper and onto the hoist
shaft.
Do not use the chiseled end of
the wheel wrench.
5. Raise the tire part way upward. Make sure the retainer is
seated in the wheel opening. 6. 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.
7. Make sure the tire is storedsecurely. Push, pull, and then
try to turn the tire. If the tire
moves, use the wheel wrench
to tighten the cable.
8. Reinstall the spare tire lock, if the vehicle has one. To store the jack and jack tools:
1. Wing Nut Retaining Wheel
Blocks
2. Wheel Blocks
3. Wing Nut Retaining Tool Kit
4. Wheel Wrench and Extensions
5. Tool Bag
6. Jack Mounting Bracket
7. Jack
8. Bolt Retaining Wheel Blocks
1. Put the tools (4) in the tool bag (5) and place them in the
retaining bracket (3).
2. Tighten down the wing nut (3).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
430 Vehicle Care
Caution
If the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
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
Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Do not lash or hook to
suspension components. Use the
proper straps around the tires to
secure the vehicle.
Use only a flatbed tow truck for
towing a disabled vehicle. Never
use a sling type lift or damage will
occur. Use ramps to help reduce
approach angles if necessary.
A towed vehicle should have its
drive wheels off the ground.
Consult a professional towing
service if the disabled vehicle must
be towed.
Front Attachment Points
The vehicle is equipped with
specific attachment points to be
used to pull the vehicle onto a
flatbed car carrier from a flat road
surface. Do not use these
attachment points to pull the vehicle
from snow, mud or sand.
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
432 Vehicle Care
Warning (Continued)
be injured. Set the parking brake
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)” underFour-Wheel
Drive 0272. Check that the
vehicle is in N (Neutral) by
shifting the transmission to
R (Reverse) and then to D
(Drive). There should be no
movement of the vehicle while
shifting.
5. Turn the engine off.
Caution
Failure to disconnect the negative
battery cable or to have it contact
the terminals can cause damage
to the vehicle.
6. Disconnect the negative battery cable at the battery and
secure the nut and bolt. Cover
the negative battery post with a
non-conductive material to
prevent any contact with the
negative battery terminal.
7. Shift the transmission to P (Park).
Caution
If the steering column is locked,
vehicle damage may occur.
8. Move the steering wheel to make sure the steering column
is unlocked. 9. With a foot on the brake pedal,
release the parking brake.
Keep the ignition key in the
towed vehicle in ACC/
ACCESSORY to prevent the
steering column from locking.
Disconnecting the Towed Vehicle
Before disconnecting the towed
vehicle: 1. Park on a level surface.
2. Set the parking brake, then shift the transmission to
P (Park), and turn the ignition
key off.
3. Connect the battery.
4. Apply the brake pedal.
5. Turn the ignition on with the engine off. Shift the transfer
case out of N (Neutral) to
Two-Wheel Drive High. See
“Shifting out of N (Neutral)”
under Four-Wheel Drive 0272.
See your dealer if the transfer
case cannot be shifted out of
N (Neutral).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
434 Vehicle Care
To dolly tow a four-wheel-drive
vehicle from the front:1. Attach the dolly to the tow vehicle following the dolly
manufacturer's instructions.
2. Drive the front wheels onto the dolly.
3. Shift the transmission to P (Park).
4. Set the parking brake.
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral). 5. Use a clamping device
designed for towing to ensure
that the front wheels are locked
into the straight position.
6. Secure the vehicle to the dolly following the manufacturer's
instructions.
7. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive 0272 for the proper
procedure.
8. Release the parking brake only after the vehicle being towed is
firmly attached to the tow
vehicle.
9. Turn the ignition off.
Rear Towing (Rear Wheels Off
the Ground)
Two-Wheel-Drive Vehicles
To dolly tow a two-wheel-drive
vehicle from the rear: 1. Drive the rear wheels onto the dolly.
2. Set the parking brake. See Parking Brake 0281.
3. Put the transmission in P (Park).
4. Secure the vehicle to the dolly following the manufacturer's
instructions.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 435
5. Use a clamping devicedesigned for towing to ensure
that the front wheels are locked
into the straight position.
6. Turn the ignition off.
Four-Wheel-Drive Vehicles
{Warning
Shifting a four-wheel-drive
vehicle's transfer case into
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or others could
be injured. Set the parking brake
before shifting the transfer case
to N (Neutral). To dolly tow a four-wheel-drive
vehicle from the rear:
1. Drive the rear wheels onto the dolly.
2. Set the parking brake. See Parking Brake 0281.
3. Put the transmission in P (Park).
4. Secure the vehicle to the dolly following the manufacturer's
instructions.
5. Use a clamping device designed for towing to ensure
that the front wheels are locked
into the straight position.
6. Shift the transfer case to N (Neutral). See “Shifting into
N (Neutral)” underFour-Wheel
Drive 0272 for the proper
procedure.
7. Turn the ignition off.
Appearance Care
Exterior Care
Locks
Locks are lubricated at the factory.
Use a de-icing agent only when
absolutely necessary, and have the
locks greased after using. See
Recommended Fluids and
Lubricants 0456.
Washing the Vehicle
To preserve the vehicle's finish,
wash it often and out of direct
sunlight.
{Warning
Do not power wash any part of
the vehicle’s interior, including the
vinyl floor covering. This could
damage safety and other systems
in the vehicle, which would not be
covered by the vehicle warranty.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 445
Reinstall by lining up the floor mat
retainer openings over the carpet
retainers and snapping into position.
Make sure the floor mat is properly
secured in place.
Verify the floor mat does not
interfere with the pedals.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
470 Customer Information
.Lock-Out Service: Service to
unlock the vehicle if you are
locked out. A remote unlock may
be available if you have OnStar.
For security reasons, the driver
must present identification
before this service is given.
. Emergency Tow from a Public
Road or Highway: Tow to the
nearest GMC dealer for warranty
service, or if the vehicle was in a
crash and cannot be driven.
Assistance is not given when the
vehicle is stuck in the sand,
mud, or snow.
. Flat Tire Change: Service to
change a flat tire with the spare
tire. The spare tire, if equipped,
must be in good condition and
properly inflated. It is the owner's
responsibility for the repair or
replacement of the tire if it is not
covered by the warranty.
. Battery Jump Start: Service to
jump start a dead battery. .
Trip Interruption Benefits and
Assistance: If your trip is
interrupted due to a warranty
event, incidental expenses may
be reimbursed within the
Powertrain warranty period.
Items considered are reasonable
and customary hotel, meals,
rental car, or a vehicle being
delivered back to the customer,
up to 500 miles.
Services Not Included in
Roadside Assistance
. Impound towing caused by
violation of any laws
. Legal fines
. Mounting, dismounting,
or changing of snow tires,
chains, or other traction devices
Service is not provided if a vehicle
is in an area that is not accessible
to the service vehicle or is not a
regularly traveled or maintained
public road, which includes ice and
winter roads. Off-road use is not
covered.
Services Specific to
Canadian-Purchased Vehicles
. Fuel Delivery: Reimbursement
is up to 7 L. Diesel fuel delivery
may be restricted. Propane and
other fuels are not provided
through this service.
. Lock-Out Service: Vehicle
registration is required.
. Trip Interruption Benefits and
Assistance: Must be over
150 km from where your trip
was started to qualify.
Pre-authorization, original
detailed receipts, and a copy of
the repair orders are required.
Once authorization has been
received, the Roadside
Assistance advisor will help to
make arrangements and explain
how to receive payment.
. Alternative Service: If
assistance cannot be provided
right away, the Roadside
Assistance advisor may give
permission to get local
emergency road service. You will
receive payment, up to $100,