service GMC SIERRA DENALI 2015 Owner's Manual

Black plate (22,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-22 Instruments and Controls vehicle needs service. A chime may
also sound when the light comes on
steady.
If the ABS light is the only light on,
the vehicle has regular brakes, but
the antilock brakes are not
functioning.
If both the ABS and the brake
system warning light are on, the
vehicle's antilock brakes are not
functioning and there is a problem
with the regular brakes. See your
dealer for service.
See Brake System Warning Light on
page 5-21 and Brake System
Messages on page 5-32 .
Four-Wheel-Drive Light The four-wheel-drive light comes on
when the transfer case is shifted
into four-wheel drive and the front
axle engages. LO or HI will also be
next to this light when the vehicle is
in four-wheel low or four-wheel high.
Some delay between the shifting
and the light coming on is normal.
See Four-Wheel Drive on
page 9-40 .
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
See Tow/Haul Mode on page 9-39 .Hill Descent Control Light
If equipped, the Hill Descent Control
light comes on when the system is
ready for use. When the light
flashes, the system is active.
See Hill Descent Control (HDC) on
page 9-51 .
Lane Departure Warning
(LDW) Light
This light is green if LDW is on and
ready to operate.

Black plate (23,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-23This light changes to amber and
flashes to indicate that the lane
marking has been crossed without
using a turn signal in that direction.
See Lane Departure Warning (LDW)
on page 9-61 .
Vehicle Ahead Indicator
If equipped, this indicator will
display green when a vehicle is
detected ahead and amber when
you are following a vehicle ahead
much too closely.
See Forward Collision Alert (FCA)
System on page 9-59 . Traction Off Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer. If the system is working
normally, the indicator light then
turns off.
The traction off light comes on when
the Traction Control System (TCS)
has been turned off by pressing and
releasing the TCS/StabiliTrak
button.
This light and the StabiliTrak OFF
light come on when StabiliTrak is
turned off.
If the TCS is off, wheel spin is not
limited. Adjust driving accordingly.
See Traction Control/Electronic
Stability Control on page 9-49 .StabiliTrak ®
OFF Light
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer.
This light comes on when the
StabiliTrak system is turned off.
If StabiliTrak is off, the Traction
Control System (TCS) is also off.
If the StabiliTrak and TCS are off,
the system does not assist in
controlling the vehicle. Turn on the
TCS and the StabiliTrak systems
and the warning light turns off.
See Traction Control/Electronic
Stability Control on page 9-49 .

Black plate (24,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-24 Instruments and Controls
Traction Control System
(TCS)/StabiliTrak ®
Light
This light comes on briefly when the
engine is started.
If the light does not come on, have
the vehicle serviced by your dealer.
If the system is working normally,
the indicator light turns off.
If the light is on and not flashing, the
TCS and potentially the StabiliTrak
system have been disabled. A DIC
message may display. Check the
DIC messages to determine which
feature(s) is no longer functioning
and whether the vehicle requires
service. If the indicator/warning light is on
and flashing, the TCS and/or the
StabiliTrak system is actively
working.
See Traction Control/Electronic
Stability Control on page 9-49 .
Engine Coolant
Temperature Warning
Light
This light comes on briefly while
starting the vehicle.
If it does not, have the vehicle
serviced by the dealer. If the system
is working normally the indicator
light goes off. { CautionThe engine coolant temperature
warning light indicates that the
vehicle has overheated. Driving
with this light on can damage the
engine and it may not be covered
by the vehicle warranty. See
Engine Overheating on
page 10-21 .
The engine coolant temperature
warning light comes on when the
engine has overheated.
If this happens, pull over and turn
off the engine as soon as possible.
See Engine Overheating on
page 10-21 .

Black plate (25,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-25
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information
about tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of
the tires are significantly
underinflated.
A Driver Information Center (DIC)
tire pressure message may also
display. See Tire Messages on
page 5-38 . Stop as soon as
possible, and inflate the tires to the
pressure value shown on the Tire
and Loading Information label. See
Tire Pressure on page 10-59 . When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light
will come on at every ignition cycle.
See Tire Pressure Monitor
Operation on page 10-62 .
Engine Oil Pressure Light
{ CautionLack of proper engine oil
maintenance can damage the
engine. Driving with the engine
oil low can also damage the
engine. The repairs would not be
covered by the vehicle warranty.
Check the oil level as soon as
possible. Add oil if required, but if
the oil level is within the operating
range and the oil pressure is still
low, have the vehicle serviced.
Always follow the maintenance
schedule for changing engine oil. This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced
by your dealer.
If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle
could be low on oil and might have
some other system problem. See
your dealer.
Low Fuel Warning Light

Black plate (26,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-26 Instruments and Controls This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working.
It also comes on when the fuel tank
is low on fuel. The light turns off
when fuel is added. If it does not,
have the vehicle serviced.
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle
serviced by your dealer. If the
system is working normally, the
indicator light turns off. If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. See Immobilizer Operation
on page 2-13 .
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer on page 6-2 .
Front Fog Lamp Light For vehicles with fog lamps, this
light comes on when the fog lamps
are on.
The light goes out when the fog
lamps are turned off. See Fog
Lamps on page 6-5 for more
information.
Lamps On Reminder
This light comes on when the
exterior lamps are in use. See
Exterior Lamp Controls on page 6-1 .

Black plate (32,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-32 Instruments and Controls SERVICE BATTERY
CHARGING SYSTEM On some vehicles, this message
displays if there is a problem with
the battery charging system. Under
certain conditions, the charging
system light may also turn on in the
instrument cluster. See Charging
System Light on page 5-18 . Driving
with this problem could drain the
battery. Turn off all unnecessary
accessories. Have the electrical
system checked as soon as
possible. See your dealer.
TRANSPORT MODE ON This message is displayed when the
vehicle is in transport mode. Some
features can be disabled while in
this mode, including Remote
Keyless Entry (RKE), remote start,
and the vehicle alarm system. Take
the vehicle to your dealer for service
to turn transport mode off. Brake System Messages BRAKE FLUID LOW This message is displayed when the
brake fluid level is low. See Brake
Fluid on page 10-27 .
SERVICE BRAKE ASSIST This message may be displayed
when there is a problem with the
brake boost assist system. When
this message is displayed, the brake
boost assist motor might be heard
operating and you might notice
pulsation in the brake pedal. This is
normal under these conditions. Take
the vehicle to your dealer for
service.
SERVICE TRAILER BRAKE
SYSTEM
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays and a chime
may sound when there is a problem
with the ITBC system. When this message displays, power
is no longer available to the trailer
brakes.
As soon as it is safe to do so,
carefully pull your vehicle over to
the side of the road and turn the
ignition off. Check the wiring
connection to the trailer and turn the
ignition back on. If this message still
displays, either your vehicle or the
trailer needs service. See your
dealer.
See “ Integrated Trailer Brake
Control System ” under Towing
Equipment on page 9-78 for more
information.
Compass Messages Dashes may be displayed if the
vehicle temporarily loses
communication with the Global
Positioning System (GPS).

Black plate (34,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-34 Instruments and Controls
Engine Oil Messages CHANGE ENGINE OIL SOON This message displays when the
engine oil needs to be changed.
When you change the engine oil, be
sure to reset the CHANGE ENGINE
OIL SOON message. See Engine
Oil Life System on page 10-11 for
information on how to reset the
message. See Engine Oil on
page 10-8 and Maintenance
Schedule on page 11-3 .
ENGINE OIL LOW ADD OIL On some vehicles, this message
displays when the engine oil level
may be too low. Check the oil level
before filling to the recommended
level. If the oil is not low and this
message remains on, take the
vehicle to your dealer for service.
See Engine Oil on page 10-8 . ENGINE OIL HOT IDLE
ENGINE This message displays when the
engine oil becomes hotter than the
normal operating temperature. Stop
and allow the vehicle to idle until it
cools down. See Engine Coolant
Temperature Gauge on page 5-13 .
OIL PRESSURE LOW STOP
ENGINE This message displays if low oil
pressure levels occur. Stop the
vehicle as soon as safely possible
and do not operate it until the cause
of the low oil pressure has been
corrected. Check the oil as soon as
possible and have the vehicle
serviced by your dealer. See Engine
Oil on page 10-8 .
Engine Power Messages ENGINE POWER IS REDUCED
This message displays and a chime
may sound when the cooling system
temperature gets too hot and the engine further enters the engine
coolant protection mode. See
Engine Overheating on page 10-21
for more information.
This message also displays when
the vehicle's engine power is
reduced. Reduced engine power
can affect the vehicle's ability to
accelerate. If this message is on,
but there is no reduction in
performance, proceed to your
destination. The performance may
be reduced the next time the vehicle
is driven. The vehicle may be driven
at a reduced speed while this
message is on, but acceleration and
speed may be reduced. Anytime
this message stays on, the vehicle
should be taken to your dealer for
service as soon as possible.

Black plate (36,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-36 Instruments and Controls when it is temporarily unavailable.
The LDW system does not need
service.
This message could be due to the
camera being blocked. Cleaning the
outside of the windshield behind the
rearview mirror may correct the
issue.
PARK ASSIST OFF This message displays when the
Parking Assist system has been
turned off or when there is a
temporary condition causing the
system to be disabled.
SERVICE FRONT CAMERA If this message remains on after
continued driving, the vehicle needs
service. Do not use the Lane
Departure Warning (LDW) and
Forward Collision Alert (FCA)
features. Take the vehicle to your
dealer. SERVICE PARKING ASSIST This message displays if there is a
problem with the Parking Assist
system. Do not use this system to
help you park. See your dealer for
service.
Ride Control System
Messages SERVICE STABILITRAK If this message displays, it means
there may be a problem with the
StabiliTrak system. If you see this
message, try to reset the system.
Stop; turn off the engine for at least
15 seconds; then start the engine
again. If this message still comes
on, it means there is a problem. You
should see your dealer for service.
The vehicle is safe to drive;
however, you do not have the
benefit of StabiliTrak, so reduce
your speed and drive accordingly. SERVICE TRACTION
CONTROL This message displays when there
is a problem with the Traction
Control System (TCS). When this
message displays, the system will
not limit wheel spin. Adjust your
driving accordingly. See your dealer
for service. See Traction Control/
Electronic Stability Control on
page 9-49 .
STABILITRAK INITIALIZING This message may come on if the
StabiliTrak system has not fully
initialized because of road
conditions or the incorrect tire size.
When the StabiliTrak system is fully
initialized, the message will turn off.
See Traction Control/Electronic
Stability Control on page 9-49 . If this
message continues to be displayed
for multiple ignition cycles and on
different road surfaces, see your
dealer for service.

Black plate (37,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-37TRACTION CONTROL OFF This message displays when the
traction control has been turned off.
See Traction Control/Electronic
Stability Control on page 9-49 .
TRACTION CONTROL ON This message displays when the
traction control is active. See
Traction Control/Electronic Stability
Control on page 9-49 .
STABILITRAK OFF This message displays when the
StabiliTrak system has been turned
off. Adjust your driving accordingly.
To limit wheel spin and realize the
full benefits of the stability
enhancement system, you should
normally leave StabiliTrak on. See
Traction Control/Electronic Stability
Control on page 9-49 . STABILITRAK OFF may also
display when the stability control
has been automatically disabled.
The following conditions can cause
this message to appear: .
The system is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time. .
The brake system warning light
is on. See Brake System
Warning Light on page 5-21 ..
The stability system takes longer
than usual to complete its
diagnostic checks due to driving
conditions. .
An engine or vehicle-related
problem has been detected and
the vehicle needs service. See
your dealer. .
The transfer case is in
Four-Wheel Drive Low.
The message turns off as soon as
the conditions that caused the
message to be displayed are no
longer present. Airbag System Messages SERVICE AIRBAG This message displays if there is a
problem with the airbag system.
Take the vehicle to your dealer for
service.
Safety Belt Messages SHIFTER LOCKED. BUCKLE
SEATBELT This message displays if the vehicle
is equipped with the Safety Belt
Assurance System and the driver
and front outboard passenger,
if present, safety belts are not
buckled. The vehicle will not shift
out of P (Park). Buckle the safety
belt(s) to unlock the shift lever.
This system may not allow the
vehicle to shift out of P (Park) if an
object - such as a briefcase,
handbag, grocery bag, laptop,
or other electronic device - is on the
front outboard passenger seat.

Black plate (38,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-38 Instruments and Controls If this happens, remove the object
from the seat or buckle the
safety belt.
If the driver or front outboard
passenger unbuckles their safety
belt while driving, the safety belt
reminder chime and light(s) will
come on. See Safety Belt
Reminders on page 5-15 .
SHIFTER UNLOCKED. BRAKE
TO SHIFT This message displays when the
Safety Belt Assurance System times
out and allows the vehicle to be
shifted out of P (Park) after
30 seconds following brake apply.
See “ Safety Belts ” and “ Child
Restraints ” in the Index for
information about the importance of
proper restraint use.
This system may not function
properly if the airbag readiness light
is on. See Airbag Readiness Light
on page 5-16 . Security Messages SERVICE THEFT DETERRENT
SYSTEM This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart, so you may want to take the
vehicle to your dealer before turning
off the engine. See Immobilizer
Operation on page 2-13 .
Steering System
Messages STEERING ASSIST IS
REDUCED DRIVE WITH CARE This message may display if a
problem occurs with the electric
power steering system. If this
message appears, steering effort
may be slightly higher than normal.
The vehicle is still safe to drive. Use
caution while in reduced assist
mode. If this message is persistent or appears repeatedly, take the
vehicle to your dealer for service.
See Steering on page 9-4 .
SERVICE POWER STEERING This message displays when there
is a problem with electric power
steering. Take the vehicle to your
dealer for service. See Steering on
page 9-4 .
Tire Messages SERVICE TIRE MONITOR
SYSTEM If equipped with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
system is not working properly. The
tire pressure light also flashes and
then remains on during the same
ignition cycle. See Tire Pressure
Light on page 5-25 . Several
conditions may cause this message
to appear. See Tire Pressure
Monitor Operation on page 10-62 .