2015 GMC SIERRA DENALI service

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 .

Black plate (40,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-40 Instruments and Controls FOR 4WD LOW SLOW TO XXX If a four-wheel drive shift into 4
n is
requested, but the vehicle speed is
too high, this message will display
until the correct vehicle speed is
reached.
GRADE BRAKING ACTIVE This message displays when grade
braking has been activated while
driving on downhill grades. This
message will only appear the first
time the feature is activated in an
ignition cycle. See Tow/Haul Mode
on page 9-39 , Automatic
Transmission on page 9-33 , and
Cruise Control on page 9-52 .
GRADE BRAKING OFF
This message displays when grade
braking has been disabled with the
Tow/Haul Mode button on the end of
the shift lever. See Tow/Haul Mode
on page 9-39 , Automatic
Transmission on page 9-33 , and
Cruise Control on page 9-52 . GRADE BRAKING ON This message displays when grade
braking has been enabled with the
Tow/Haul Mode button on the end of
the shift lever. See Tow/Haul Mode
on page 9-39 , Automatic
Transmission on page 9-33 , and
Cruise Control on page 9-52 .
SERVICE 4WD If the vehicle has four-wheel drive,
this message may display if a
problem occurs with the
four-wheel-drive system. If this
message appears, stop as soon as
possible and turn off the vehicle.
Make sure the key is in the LOCK/
OFF position for at least
one minute, then restart the vehicle
and check for the message on the
DIC display. If the message is still
displayed or appears again when
you begin driving, the
four-wheel-drive system needs
service. See your dealer. SHIFT DENIED This message displays when the
shift lever is in M (Manual Mode)
and a transmission range has been
selected that is unavailable at the
current vehicle speed.
TO EXIT 4WD LOW SHIFT TO
NEUTRAL If a four-wheel drive shift out of 4
n is
requested, and the vehicle speed is
correct, but the transmission is not
in N (Neutral), this message will
display until the transmission is
shifted to N (Neutral).
TO EXIT 4WD LOW SLOW
TO XXX
If a four-wheel drive shift out of 4
n is
requested, but the vehicle speed is
too high, this message will display
until the correct vehicle speed is
reached.

Black plate (41,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-41TRANSMISSION HOT IDLE
ENGINE This message displays and a chime
may sound if the transmission fluid
in the vehicle gets hot. Driving with
the transmission fluid temperature
high can cause damage to the
vehicle. Stop the vehicle and let it
idle to allow the transmission to
cool. This message clears and the
chime stops when the fluid
temperature reaches a safe level.
When towing, use Tow/Haul Mode
to prevent damage to the engine or
transmission. See Tow/Haul Mode
on page 9-39 .
VEHICLE IN 4WD LOW This message will display if the
vehicle is driven in 4
n for about
10 minutes above 72 km/h (45 mph). Vehicle Reminder
Messages CHECK TRAILER WIRING On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message may display and a
chime may sound when one of the
following conditions exists: .
A trailer with electric brakes
becomes disconnected from the
vehicle.
‐ If the disconnect occurs while
the vehicle is stopped, this
message clears itself after a
short time.
‐ If the disconnect occurs while
the vehicle is moving, this
message stays on until the
ignition is turned off. .
There is a short in the wiring to
the electric trailer brakes.
When this message displays, power
is no longer available to the trailer
brakes. As soon as it is safe to do so,
carefully pull the 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. This message clears if the trailer
is reconnected. This message also
clears if you acknowledge it. If this
message still displays, either the
vehicle or the trailer needs service.
See your dealer.
See “ Integrated Trailer Brake
Control System ” under Towing
Equipment on page 9-78 .
ICE POSSIBLE DRIVE
WITH CARE This message displays when ice
conditions are possible.
TRAILER CONNECTED
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays briefly when
a trailer with electric or electric over
hydraulic brakes is first connected
to the vehicle.