2015 GMC SIERRA tow

Black plate (14,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
5-14 Instruments and Controls
English, Standard Theme Shown
This gauge measures the
temperature of the vehicle's engine
coolant.
While driving under normal
operating conditions, if the needle
moves into the red warning area,
the engine is too hot. Pull off the
road, stop the vehicle, and turn off
the engine as soon as possible.
Transmission
Temperature Gauge
Metric, Standard Theme Shown
English, Standard Theme Shown
This gauge appears when the
vehicle is in Tow/Haul Mode and
shows the transmission fluid
temperature. If the gauge is reading
in the red area and/or a message
appears in the Driver Information
Center (DIC), the vehicle must be
stopped and the cause checked.
One possible cause is a low fluid
level in the transmission.
See Transmission Messages on
page 5-39.

Black plate (19,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-19
{Caution
If the vehicle is continually driven
with this light on, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
{Caution
Modifications made to the engine,
transmission, exhaust, intake,
or fuel system of the vehicle or
the replacement of the original
tires with other than those of the
same Tire Performance Criteria
(TPC) can affect the vehicle's
emission controls and can cause
this light to come on.
Modifications to these systems(Continued)
Caution (Continued)
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test. See
Accessories and Modifications on
page 10-3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.
To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled as
soon as it is possible.
If the light continues to flash, find a
safe place to stop and park the
vehicle. Turn the vehicle off, wait at
least 10 seconds, and restart the
engine. If the light is still flashing,
follow the previous steps and see
your dealer for service as soon as
possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.
The following may correct an
emission control system
malfunction:
.Check that the fuel cap is fully
installed. See Filling the Tank on
page 9-66. The diagnostic
system can determine if the fuel
cap has been left off or
improperly installed. A loose or
missing fuel cap allows fuel to
evaporate into the atmosphere.

Black plate (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-21
Brake System Warning
Light
The vehicle brake system consists
of two hydraulic circuits. If one
circuit is not working, the remaining
circuit can still work to stop the
vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on, there
is a brake problem. Have the brake
system inspected right away.
MetricEnglish
This light should come on briefly
when the engine is started. If it does
not come on then, have it fixed so it
will be ready to warn if there is a
problem. When the ignition is on, the brake
system warning light also comes on
when the parking brake is set. The
light stays on if the parking brake
does not fully release. If it stays on
after the parking brake is fully
released, it means the vehicle has a
brake problem.
If the light comes on while driving,
pull off the road and stop carefully.
The pedal might be harder to push,
or the pedal can go closer to the
floor. It may take longer to stop.
If the light is still on, have the
vehicle towed for service. See
Towing the Vehicle on page 10-91.
{Warning
The brake system might not be
working properly if the brake
system warning light is on.
Driving with the brake system
warning light on can lead to a
crash. If the light is still on after
the vehicle has been pulled off
(Continued)
Warning (Continued)
the road and carefully stopped,
have the vehicle towed for
service.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine is started.
If the light does not come on, have it
fixed so it will be ready to warn if
there is a problem.
If the light comes on while driving,
stop as soon as it is safely possible
and turn off the vehicle. Then start
the engine again to reset the
system. If the ABS light stays on,
or comes on again while driving, the

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.
SeeBrake System Warning Light on
page 5-21 andBrake 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.
SeeHill 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 (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. SeeCharging
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” underTowing
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 (33,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Instruments and Controls 5-33
Door Ajar Messages
DOOR OPEN
This message displays and a chime
may sound if a door is not fully
closed. Stop and turn off the
vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
HOOD OPEN
This message displays and a chime
may sound if the hood is not fully
closed. Stop and turn off the
vehicle, check the hood for
obstructions, and close the hood
again. Check to see if the message
still appears on the DIC.
Engine Cooling System
Messages
A/C OFF DUE TO HIGH
ENGINE TEMP
This message displays when the
engine coolant becomes hotter than
the normal operating temperature.
SeeEngine Coolant Temperature
Gauge on page 5-13. To avoid
added strain on a hot engine, the air
conditioning compressor
automatically turns off. When the
coolant temperature returns to
normal, the air conditioning
compressor turns back on. You can
continue to drive your vehicle.
If this message continues to appear,
have the system repaired by your
dealer as soon as possible to avoid
damage to the engine.
ENGINE OVERHEATING IDLE
ENGINE
This message displays when the
engine coolant temperature is too
hot. Stop and allow the vehicle to
idle until it cools down. See Engine
Coolant Temperature Gauge on
page 5-13.
When towing, use Tow/Haul mode
to prevent damage to the engine or
transmission. See Tow/Haul Mode
on page 9-39.
ENGINE OVERHEATED STOP
ENGINE
This message displays and a chime
may sound if the engine cooling
system reaches unsafe
temperatures for operation. Stop
and turn off the vehicle as soon as it
is safe to do so to avoid severe
damage. This message clears when
the engine has cooled to a safe
operating temperature.

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 4nis
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 4nis
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 4nis
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 5-41
TRANSMISSION 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. SeeTow/Haul Mode
on page 9-39.
VEHICLE IN 4WD LOW
This message will display if the
vehicle is driven in 4
nfor 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” underTowing
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.