2015 GMC SIERRA DENALI automatic transmission

Black plate (6,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-6 Vehicle Care 1. Positive (+) Terminal. See Jump
Starting on page 10-87 .
2. Battery on page 10-29 .
3. Coolant Surge Tank and
Pressure Cap. See Cooling
System on page 10-17 .
4. Engine Air Cleaner/Filter on
page 10-15 .
5. Automatic Transmission Dipstick
(If Equipped). See “ How to
Check the Automatic
Transmission Fluid ” under
Automatic Transmission Fluid (6
Speed Transmission) on
page 10-12 or Automatic
Transmission Fluid (8 Speed
Transmission) on page 10-15 . 6. Remote Negative (-) Location.
See Jump Starting on
page 10-87 .
7. Engine Cooling Fans (Out of
View). See Cooling System on
page 10-17 .
8. Engine Oil Fill Cap. See “ When
to Add Engine Oil ” under Engine
Oil on page 10-8 .
9. Engine Oil Dipstick. See
“ Checking Engine Oil ” under
Engine Oil on page 10-8 . 10. Windshield Washer Fluid
Reservoir. See “ Adding Washer
Fluid ” under Washer Fluid on
page 10-25 .
11. Brake Fluid Reservoir. See
Brake Fluid on page 10-27 .
12. Engine Compartment Fuse
Block on page 10-41 .

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-8 Vehicle Care 1. Positive (+) Terminal. See Jump
Starting on page 10-87 .
2. Battery on page 10-29 .
3. Coolant Surge Tank and
Pressure Cap. See Cooling
System on page 10-17 .
4. Engine Air Cleaner/Filter on
page 10-15 .
5. Automatic Transmission
Dipstick. See “ How to Check the
Automatic Transmission Fluid ”
under Automatic Transmission
Fluid (6 Speed Transmission) on
page 10-12 or Automatic
Transmission Fluid (8 Speed
Transmission) on page 10-15 .
6. Engine Oil Dipstick. See
“ Checking Engine Oil ” under
Engine Oil on page 10-8 .
7. Engine Oil Fill Cap. See “ When
to Add Engine Oil ” under Engine
Oil on page 10-8 .
8. Engine Cooling Fan (Out of
View). See Cooling System on
page 10-17 . 9. Remote Negative ( – ) Location.
See Jump Starting on
page 10-87 .
10. Power Steering Fluid
Reservoir. See Power Steering
Fluid (1500 Series) on
page 10-24 or Power Steering
Fluid (2500/3500 Series) on
page 10-24 .
11. Windshield Washer Fluid
Reservoir. See “ Adding Washer
Fluid ” under Washer Fluid on
page 10-25 .
12. Brake Fluid Reservoir. See
Brake Fluid on page 10-27 .
13. Auxiliary Battery (If Equipped).
See Battery on page 10-29 .
14. Engine Compartment Fuse
Block on page 10-41 .
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement. Engine Oil For diesel engine vehicles, see
“ Engine Oil ” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment: .
Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“ Selecting the Right Engine Oil ”
in this section. .
Check the engine oil level
regularly and maintain the
proper oil level. See “ Checking
Engine Oil ” and “ When to Add
Engine Oil ” in this section. .
Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-11 . .
Always dispose of engine oil
properly. See “ What to Do with
Used Oil ” in this section.

Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-12 Vehicle Care The oil life system can also be reset
as follows:
1. Turn the ignition to ON/RUN with
the engine off.
2. Fully press the accelerator pedal
slowly three times within
five seconds.
3. Display the OIL LIFE
REMAINING on the DIC. If the
display shows 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
REMAINING is near 0%, the engine
oil life system has not been reset.
Repeat the procedure. Automatic Transmission
Fluid (6 Speed
Transmission) 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. If a small leak is
suspected, then use the following
checking procedures to check the
fluid level. However, if there is a
large leak, then it may be necessary
to have the vehicle towed to a
dealer service department and have
it repaired before driving the vehicle
further.
{ Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
(Continued) Caution (Continued) not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-12 .
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-3 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-12 .
How to Check Automatic
Transmission Fluid
{ Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
(Continued)

Black plate (15,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-155. Safe operating level is within the
HOT cross hatch band on the
dipstick. If the fluid level is not
within the HOT band, and the
transmission temperature is
between 71°C and 93°C (160°F
and 200°F), add or drain fluid as
necessary to bring the level into
the HOT band. If the fluid level is
low, add only enough fluid to
bring the level into the HOT
band. It does not take much
fluid, generally less than 0.5 L
(1 pt). Do not overfill.
6. If the fluid level is in the
acceptable range, push the
dipstick back in all the way, then
flip the handle down to lock the
dipstick in place.
Consistency of Readings
Always check the fluid level at least
twice using the procedure described
previously. Consistency (repeatable
readings) is important to maintaining
proper fluid level. If readings are still
inconsistent, contact the dealer. Automatic Transmission
Fluid (8 Speed
Transmission) 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 Service
Publications Ordering Information
on page 13-11 .{ CautionUse of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-12 .
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule on
page 11-3 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-12 .
Engine Air Cleaner/Filter If the vehicle has a diesel engine,
see “ Pickup Models ” under “ Engine
Air Cleaner/Filter ” in the Duramax
diesel supplement for the correct
inspection and replacement
procedures.

Black plate (34,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-34 Vehicle Care
Automatic Transmission
Shift Lock Control
Function Check
{ WarningWhen 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.
Ignition Transmission
Lock Check While parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position. .
The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park). .
The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required. Park Brake and P (Park)
Mechanism Check
{ WarningWhen you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake. .
To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.

Black plate (56,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-56 Vehicle Care (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; and the letter B
means belted-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).
Accessory Weight :
The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio :
The relationship
of a tire's height to its width. Belt :
A rubber coated layer of
cords 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 Pressure
on page 10-59 .
Curb Weight :
The weight of a
motor vehicle with standard and
optional equipment including the

Black plate (75,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-75
{ WarningLifting a vehicle and getting under
it to do maintenance or repairs is
dangerous without the
appropriate safety equipment and
training. If a jack is provided with
the vehicle, it is designed only for
changing a flat tire. If it is used for
anything else, you or others could
be badly injured or killed if the
vehicle slips off the jack. If a jack
is provided with the vehicle, only
use it for changing a flat tire.
If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place, well off the road,
if possible. Turn on the hazard
warning flashers. See Hazard
Warning Flashers on page 6-4 .{ WarningChanging a tire can be
dangerous. The vehicle can slip
off the jack and roll over or fall
causing injury or death. Find a
level place to change the tire. To
help prevent the vehicle from
moving:
1. Set the parking brake firmly.
2. Put an automatic
transmission in P (Park) or a
manual transmission in
1 (First) or R (Reverse).
3. For four-wheel-drive
vehicles, be sure the
transfer case is in a drive
gear – not in N (Neutral).
4. Turn off the engine and do
not restart while the vehicle
is raised.
5. Do not allow passengers to
remain in the vehicle.
(Continued) Warning (Continued) 6. Place wheel blocks on both
sides of the tire at the
opposite corner of the tire
being changed.
When the vehicle has a flat tire (2),
use the following example as a
guide to assist in the placement of
the wheel blocks (1).
1. Wheel Block
2. Flat Tire
The following information explains
how to use the jack and change
a tire.

Black plate (88,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-88 Vehicle Care begin that, especially in cold
weather, you may not be able to
get enough power from a single
battery in another vehicle to start
your diesel engine. If your
vehicle has more than one
battery, using the battery that is
closer to the starter will reduce
electrical resistance. This is
located on the passenger side,
in the rear of the engine
compartment.
3. Get the vehicles close enough
so the jumper cables can reach,
but be sure the vehicles are not
touching each other. 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) or a
manual transmission in Neutral 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).
{ CautionIf 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 off the ignition 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.
The positive (+) terminal is under
a red plastic cover at the positive
battery post. To uncover the
positive (+) terminal, open the
red plastic cover.
For more information on the
location of the remote
positive (+) and remote negative
( − ) terminals, see Engine
Compartment Overview on
page 10-5 .
{ 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.