
Black plate (13,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-13
Caution (Continued)
system parts, starting a fire. Too
little fluid could cause the
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Before checking the fluid level,
prepare the vehicle:
1. Start the engine and park the vehicle on a level surface. Keep
the engine running.
2. Apply the parking brake and place the shift lever in P (Park).
3. With your foot on the brake pedal, move the shift lever
through each gear range,
pausing for about three seconds
in each range. Then, move the
shift lever back to P (Park).
4. Allow the engine to idle (500– 800 rpm) for at least one minute.
Slowly release the brake pedal. 5. Keep the engine running and
check the transmission fluid
temperature on the Driver
Information Center (DIC). See
Driver Information Center (DIC)
on page 5-27.
6. Using the transmission fluid temperature reading, determine
and perform the appropriate
check procedure. If the
transmission fluid temperature
reading is not within the required
temperature ranges, allow the
vehicle to cool, or operate the
vehicle until the appropriate
transmission fluid temperature is
reached.
Cold Check Procedure
Use this procedure only as a
reference to determine if the
transmission has enough fluid to be
operated safely until a hot check
procedure can be made. The hot
check procedure is the most
accurate method to check the fluid
level. Perform the hot check
procedure at the first opportunity. Use this cold check procedure to
check fluid level when the
transmission temperature is
between 27°C and 32°C (80°F and
90°F).
1. Locate the transmission dipstick
at the rear of the engine
compartment, on the passenger
side of the vehicle.
See Engine Compartment
Overview on page 10-5.
2. Flip the handle up, then pull out the dipstick and wipe it with a
clean rag or paper towel.
3. Install the dipstick by pushing it back in all the way; wait
three seconds, and then pull it
back out again. 

Black plate (33,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-33
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
underhood insulation.
Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications. Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner.
Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{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.
2. Apply both the parking brake and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service. 

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
{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.
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
{Warning
When 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 (35,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-35
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking.
Replacement blades come in
different types and are removed in
different ways. For proper
windshield wiper blade length and
type, see Maintenance
Replacement Parts on page 11-14.
{Caution
Allowing the wiper arm to touch
the windshield when no wiper
blade is installed could damage
the windshield. Any damage that
(Continued)
Caution (Continued)
occurs would not be covered by
your warranty. Do not allow the
wiper arm to touch the windshield.
To replace the windshield wiper
blade:
1. Pull the windshield wiper assembly away from the
windshield.
2. Press the button (2) in themiddle of the wiper arm
connector, and pull the wiper
blade away from the arm
connector (1).
3. Remove the wiper blade.
4. Reverse Steps 1–3 for wiper blade replacement.
Glass Replacement
If the windshield or front side glass
must be replaced, see your dealer
to determine the correct
replacement glass. 

Black plate (43,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-43
Micro
J-Case Fuses Usage
1 Trailer Brake
2 Trailer Battery
J-Case Fuses Usage
3 Antilock Brake System Pump
4 Instrument Panel BEC 1
5 Spare
6 4WD Trec
7 Spare
8 Instrument Panel BEC 2
9 Spare
10 Rear Window Defogger
11 Starter J-Case
Fuses Usage
12 Cooling Fan 1
13 Cooling Fan 2
Mini Fuses (2 Pin) Usage
14 Trailer Stop/Turn Lamps, Left
15 Trailer Parking Lamps
16 Trailer Back-up Lamp
17 Trailer Stop/Turn Lamps, Right
Micro Fuses (2 Pin) Usage
18 Fuel Pump
19 Integrated Chassis Control Module Micro Fuses
(2 Pin) Usage
20 Electronic Suspension
Control Module
21 Fuel Pump Power Module
22 Upfitter Switch 1
23 Upfitter 2
24 Front Wiper
25 Antilock Brake System Valves
26 Upfitter SW 2
27 Upfitter SW 3
28 Parking Lamps, Right
29 Parking Lamps, Left
30 Upfitter 3
31 Upfitter SW 4
32 Upfitter 4 

Black plate (64,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-64 Vehicle Care
.Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels
other than those recommended
could prevent the TPMS from
functioning properly. SeeBuying
New Tires on page 10-69.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly, it cannot detect or signal a
low tire condition. See your dealer
for service if the TPMS malfunction
light and DIC message come on
and stay on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new
tire/wheel position after rotating the
vehicle’s tires or replacing one or
more of the TPMS sensors. Also,
the TPMS sensor matching process should be performed after replacing
a spare tire with a road tire
containing the TPMS sensor. The
malfunction light and the DIC
message should go off at the next
ignition cycle. The sensors are
matched to the tire/wheel positions,
using a TPMS relearn tool, in the
following order: driver side front tire,
passenger side front tire, passenger
side rear tire, and driver side rear.
See your dealer for service or to
purchase a relearn tool. A TPMS
relearn tool can also be purchased.
See Tire Pressure Monitor
Sensor Activation Tool at
www.gmtoolsandequipment.com or
call 1-800-GM TOOLS
(1-800-468-6657).
There are two minutes to match the
first tire/wheel position, and
five minutes overall to match all four
tire/wheel positions. If it takes
longer, the matching process stops
and must be restarted.
The TPMS sensor matching
process is:
1. Set the parking brake.
2. Turn the ignition to ON/RUN with
the engine off.
3. Make sure the Tire Pressure info page option is turned on. The
info pages on the DIC can be
turned on and off through the
Settings menu. See Driver
Information Center (DIC) on
page 5-27.
4. Use the DIC controls on the right side of the steering wheel to
scroll to the Tire Pressure
screen under the DIC info page.
5. Press and hold the
V(Set/
Reset) button located in the
center of the DIC controls.
The horn sounds twice to signal
the receiver is in relearn mode
and the TIRE LEARNING
ACTIVE message displays on
the DIC screen. 

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
{Warning
Lifting 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.
{Warning
Changing 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 bothsides 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).
{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 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.