2017 GMC SIERRA DENALI brake light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 277To control the fast idle:
.
To enable the Fast Idle System,
press and release the cruise
control on/off button and ensure
that the switch indicator light
is lit.
.
Press and release the cruise
control SET- button. Engine
speed will be held at
approximately 1200 rpm.
One of the following actions will turn
off the fast idle:
.
Pressing the brake.
.
Selecting the cruise control
cancel button.
.
Releasing the parking brake.
.
Moving the transmission shift
lever out of P (Park) or
N (Neutral).
.
Selecting the cruise control on/
off button when it was
previously on.
.
Pressing the cruise control SET-
button a second time. .
Pressing the accelerator more
than one-quarter of the
way down.
.
Turning the ignition off.
Retained Accessory
Power (RAP) The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.
Audio System
.
Power Windows
.
OnStar System (if equipped)
.
Sunroof (if equipped)
These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes or until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened. Accessory Power Outlets (APOs)
The vehicle may have Accessory
Power Outlets (APOs) in several
locations. See Power Outlets 0 128 .
The APOs in the console or center
seat position are powered by
Retained Accessory Power (RAP).
They will continue to work for up to
10 minutes after the key is turned
from ON/RUN to LOCK/OFF, or until
the driver door is opened.
The APOs on the center stack come
from the factory powered directly
from the vehicle battery, and supply
accessory power at all times,
regardless of ignition key position.
If electronic items are left plugged
into these APOs for long periods of
time with the vehicle off, the vehicle
battery could be drained. The
vehicle may not start if the battery is
allowed to drain for an extended
period of time.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
288 Driving and Operating Low Traction Mode If equipped, Low Traction Mode
assists in vehicle acceleration when
road conditions are slippery, such
as with ice or snow. While the
vehicle is at a stop, select L2 using
Range Selection Mode. This will
limit torque to the wheels and help
to prevent the tires from spinning.
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling. This provides increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, when towing, or when
hauling heavy loads.
The selector button is on the end of
the shift lever. Turn the Tow/Haul
Mode on and off by pressing the
button. When the Tow/Haul Mode is
enabled, a light on the instrument
cluster will come on.
For an eAssist vehicle, the Stop/
Start function will become
unavailable when Tow/Haul Mode is
active.
For an eAssist vehicle, the
Regenerative Braking functionality is
disabled when using the Tow/Haul
Mode. See the eAssist supplement.
See Tow/Haul Mode Light 0 147 and
Hill and Mountain Roads 0 262 .
Also see “ Tow/Haul Mode ” under
Towing Equipment 0 340 .
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is not in the Range Selection Mode.
See “ Tow/Haul Mode ” listed
previously and Manual Mode 0 286 .
Tow/Haul Mode Grade Braking
assists in maintaining desired
vehicle speeds when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
If equipped, on vehicles with a
gasoline engine, to disable or
enable Tow/Haul Grade Braking
within the current ignition key cycle,
press and hold the Tow/Haul button
for five seconds. When the button is
released, the requested mode
change is made. A DIC message is
displayed. See Transmission
Messages 0 164 .
On vehicles with a diesel engine,
Tow/Haul Mode Grade Braking can
be enabled or disabled by pressing
the Tow/Haul Mode button. Use the
exhaust brake and Tow/Haul Mode
for maximum grade braking.
See Towing Equipment 0 340 .
For other forms of grade braking,
see Automatic Transmission 0 283
and Cruise Control 0 302 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/19/17
Driving and Operating 289
Drive Systems Four-Wheel Drive If equipped, four-wheel drive
engages the front axle for extra
traction. Read the appropriate
section for transfer case operation
before using.
CautionDo not drive on clean, dry
pavement in 4
m and 4
n (if
equipped) for an extended period
of time. These conditions may
cause premature wear on the
vehicle ’ s powertrain.
Driving on clean, dry pavement in
4
m or 4
n may:
.
Cause a vibration to be felt in
the steering system.
.
Cause tires to wear faster.
.
Make the transfer case harder to
shift, and cause it to run noisier. { WarningShifting the transfer case to
N (Neutral) can cause the vehicle
to roll even if the transmission is
in P (Park). You or someone else
could be seriously injured. Be
sure to set the parking brake
before placing the transfer case in
N (Neutral). See Parking Brake
0 297 .
CautionExtended high-speed operation in
4
n may damage or shorten the
life of the drivetrain.
Engagement noise and bump when
shifting between 4
n and 4
m or from
N (Neutral), with the engine running,
is normal.
Shifting into 4
n will turn Traction
Control and StabiliTrak ®
off. See
Traction Control/Electronic Stability
Control 0 299 . Manual Transfer Case
Move the lever to shift into and out
of four-wheel drive.
An indicator light comes on when
four-wheel drive is engaged. See
Four-Wheel-Drive Light 0 147 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 2914. Shifting with the vehicle at a
stop may be more difficult. It is
possible that the shift will not
complete and the transfer case
will remain in N (Neutral). This
is normal. To complete the
shift, with the engine running,
shift the transmission to
D (Drive) and back to
N (Neutral), and reattempt the
transfer case shift.
Shifting In or Out of N (Neutral)
1. Have the engine running.
2. Set the parking brake. Press
and hold the brake pedal. See
Parking Brake 0 297 .
3. Place the transmission into
N (Neutral).
4. Shift the transfer case lever in
one continuous motion into or
out of N (Neutral). Electronic Transfer Case
Use the transfer case knob, next to
the steering wheel, to shift into and
out of four-wheel drive for extra
traction.
All of the lights will blink on then off
momentarily when the ignition is
moved to the ON/RUN position. The
light that remains on will indicate the
state of the Transfer Case.
If the indicator mark on the switch
does not match up with the light
then that likely means the switch
was moved when the ignition
was off. The indicator mark on the switch
must line up with the indicator light
before a shift can be commanded.
To command a shift rotate the
transfer case switch to the new
desired position. The light will blink
meaning that the shift is in progress.
When the shift is completed the new
position will be illuminated. If the
transfer case can not complete a
shift command, it will go back to its
last chosen setting.
CautionShifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
The settings are:
N (Neutral) : Use only when the
vehicle needs to be towed.
See Recreational Vehicle Towing
0 440 or Towing the Vehicle 0 439 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 2932. Turn the knob to 4
m or 2
m .
Wait for the 4
m or 2
m indicator
light to stop flashing before
shifting the transmission
into gear.
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
m or 2
m indicator light will flash
for 30 seconds, but will not complete
the shift. With the vehicle moving
less than 5 km/h (3 mph), and the
transmission in N (Neutral), attempt
the shift again.
Shifting Into N (Neutral)
To shift:
1. Park the vehicle on a level
surface.
2. Set the parking brake and
press and hold the brake
pedal. See Parking Brake
0 297 .
3. Start the vehicle or turn the
ignition to ON/RUN.
4. Shift the transmission to
N (Neutral). 5. Shift the transfer case to 2
m .
6. Turn the transfer case knob
clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly
release the dial to the 4
nposition. The N (Neutral) light
will come on when the transfer
case shift to N (Neutral) is
complete.
7. With the engine running, verify
that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then to D (Drive). There should
be no movement of the vehicle
while shifting the transmission.
8. Turn the engine off, and the
ignition to ACC/ACCESSORY.
9. Place the transmission shift
lever in P (Park). See
Recreational Vehicle Towing
0 440 .
10. Turn the ignition to LOCK/OFF. Shifting Out of N (Neutral)
To shift:
1. Set the parking brake and
apply the brake pedal.
2. Turn the ignition to ON/RUN
with the engine off.
3. Shift the transmission to
N (Neutral).
4. Turn the transfer case knob to
2
m .
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
Caution
Shifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case.
6. Start the engine and shift the
transmission to the
desired gear.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
296 Driving and Operating If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
m , AUTO, or 2
m indicator light
will flash for 30 seconds but will not
complete the shift. With the vehicle
moving less than 5 km/h (3 mph),
and the transmission in N (Neutral),
attempt the shift again.
Shifting Into N (Neutral)
To shift into N (Neutral):
1. Park the vehicle on a level
surface.
2. Set the parking brake and
press and hold the brake
pedal. See Parking Brake
0 297 .
3. Start the vehicle or turn the
ignition to ON/RUN.
4. Shift the transmission to
N (Neutral).
5. Shift the transfer case to 2
m . 6. Turn the transfer case knob
clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly
release the dial to the 4
nposition. The N (Neutral) light
will come on when the transfer
case shift to N (Neutral) is
complete.
7. With the engine running, verify
that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then shift the transmission to
D (Drive). There should be no
movement of the vehicle while
shifting the transmission.
8. Turn the engine off, and the
ignition to ACC/ACCESSORY.
9. Place the transmission shift
lever in P (Park). See
Recreational Vehicle Towing
0 440 .
10. Turn the ignition to LOCK/OFF. Shifting Out of N (Neutral)
To shift out of N (Neutral):
1. Set the parking brake and
apply the brake pedal.
2. Turn the ignition to ON/RUN
with the engine off.
3. Shift the transmission to
N (Neutral).
4. Turn the transfer case knob to
the desired setting.
After the transfer case has
shifted out of N (Neutral), the
N (Neutral) light will go out.
5. Release the parking brake.
6. Start the engine and shift the
transmission to the
desired gear.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Driving and Operating 297
Brakes Antilock Brake
System (ABS) This vehicle has an Antilock Brake
System (ABS), an advanced
electronic braking system that helps
prevent a braking skid.
When the vehicle begins to drive
away, ABS checks itself.
A momentary motor or clicking noise
may be heard while this test is going
on, and it may even be noticed that
the brake pedal moves a little. This
is normal.
If there is a problem with ABS, this
warning light stays on. See Antilock
Brake System (ABS) Warning Light
0 146 . If driving safely on a wet road and it
becomes necessary to slam on the
brakes and continue braking to
avoid a sudden obstacle, a
computer senses the wheels are
slowing down. If one of the wheels
is about to stop rolling, the computer
will separately work the brakes at
each wheel.
ABS can change the brake pressure
to each wheel, as required, faster
than any driver could. This can help
you steer around the obstacle while
braking hard.
As the brakes are applied, the
computer keeps receiving updates
on wheel speed and controls
braking pressure accordingly.
Remember: ABS does not change
the time needed to get a foot up to
the brake pedal or always decrease
stopping distance. If you get too
close to the vehicle in front of you,
there will not be enough time to
apply the brakes if that vehicle
suddenly slows or stops. Always
leave enough room up ahead to
stop, even with ABS. Using ABS Do not pump the brakes. Just hold
the brake pedal down firmly and let
ABS work. You may hear the ABS
pump or motor operating and feel
the brake pedal pulsate. This is
normal.
Braking in Emergencies ABS allows you to steer and brake
at the same time. In many
emergencies, steering can help
more than even the very best
braking.
Parking Brake

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
298 Driving and Operating Set the parking brake by holding the
regular brake pedal down, then
pushing down the parking brake
pedal.
If the ignition is on, the brake
system warning light will come on.
See Brake System Warning Light
0 145 .
CautionDriving with the parking brake on
can overheat the brake system
and cause premature wear or
damage to brake system parts.
Make sure that the parking brake
is fully released and the brake
warning light is off before driving.
To release the parking brake, hold
the regular brake pedal down, then
push down momentarily on the
parking brake pedal until you feel
the pedal release. Slowly pull your
foot up off the parking brake pedal.
If the parking brake is not released
when you begin to drive, the brake system warning light will flash and a
chime will sound warning you that
the parking brake is still on.
If you are towing a trailer and are
parking on a hill, see Driving
Characteristics and Towing Tips
0 320 .
Brake Assist The Brake Assist feature is
designed to assist the driver in
stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal as the driving situation dictates. The
Brake Assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.
Hill Start Assist (HSA) This vehicle has a Hill Start Assist
(HSA) feature, which may be useful
when the vehicle is stopped on a
grade. This feature is designed to
prevent the vehicle from rolling,
either forward or rearward, during
vehicle drive off. After you
completely stop and hold the vehicle
in a complete standstill on a grade,
HSA will automatically activate.
During the transition period between
when you release the brake pedal
and start to accelerate to drive off
on a grade, HSA holds the braking
pressure for a maximum of
two seconds to ensure that there is
no rolling. The brakes will
automatically release when the
accelerator pedal is applied within
the two-second window. If the
vehicle is equipped with the
Integrated Trailer Brake Control