
Black plate (6,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-6 Lighting
Holding the turn signal lever for
more than one second will cause
the turn signals to flash until you
release the lever.
The lever returns to its starting
position whenever it is released.
If after signaling a turn or a lane
change the arrows flash rapidly or
do not come on, a signal bulb could
be burned out.
Have the bulbs replaced. If the bulb
is not burned out, check the fuse.
SeeFuses and Circuit Breakers on
page 10‑44.
Turn Signal On Chime
If the turn signal is left on for more
than 1.2 km (0.75 mi), a chime will
sound at each flash of the turn
signal and the message TURN
SIGNAL ON will also appear in the
Driver Information Control (DIC). To
turn the chime and message off,
move the turn signal lever to the off
position.Fog Lamps
For vehicles with fog lamps, the
control is located next to the exterior
lamps control on the instrument
panel, to the left of the steering
column.
The ignition must be in the ON/RUN
position for the fog lamps to
come on.
#(Fog Lamps): Press to turn the
fog lamps on or off. A light will come
on in the instrument panel cluster.
When the fog lamps are turned on,
the parking lamps automatically
turn on.
When the headlamps are changed
to high beam, the fog lamps also go
off. When the high-beam headlamps
are turned off, the fog lamps will
come on again.
Some localities have laws that
require the headlamps to be on with
the fog lamps.
Auxiliary
Roof-Mounted Lamp
If the vehicle has this feature, this
button includes wiring provisions for
a dealer or a qualified service center
to install an auxiliary roof lamp.

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-7
This button is located on the
overhead console.
When the wiring is connected to
an auxiliary roof‐mounted lamp,
pressing the bottom of the button
will activate the lamp and illuminate
an indicator light at the bottom of
this button. Pressing the top of the
button will turn off the roof‐mounted
lamp and indicator.The emergency roof lamp circuit
is fused at 30 amps, so the total
current draw of the attached lamps
should be less than this value. The
attachment points for the roof lamp
circuits are two blunt cut wires
located above the overhead
console, a dark green switched
power wire and a black ground wire.
For more information on roof mount
emergency lamp installation, please
visit the GM Upfitter website at
www.gmupfitter.com or contact your
dealer.
If the vehicle has this button,
the vehicle may have the snow
plow prep package. For further
information, see
Adding a Snow
Plow or Similar Equipment on
page 9‑106.
Interior Lighting
Instrument Panel
Illumination Control
D(Instrument Panel
Brightness): This feature controls
the brightness of the instrument
panel lights and is located next to
the exterior lamps control.
Push the knob to extend out and
then it can be turned.
Turn the knob clockwise or
counterclockwise to brighten or dim
the instrument panel lights. Turning
the knob to the farthest clockwise
position turns on the dome lamps.

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-8 Lighting
Cargo Lamp
The cargo lamps come on by
turning the instrument panel
brightness control knob to the
farthest clockwise position. This
knob is located on the instrument
panel and also turns on the dome
lamps.
The cargo lamps can be used if
more light is needed in the cargo
area of the vehicle or in the top-box
storage units.
Dome Lamps
The dome lamps are located in the
overhead console.
They come on when any door is
opened and turn off after all the
doors are closed.
Turn the instrument panel
brightness knob located below
the dome lamp override button,
clockwise to the farthest position to
manually turn on the dome lamps.
The dome lamps remain on until the
knob is turned counterclockwise.Dome Lamp Override
The dome lamp override button is
located next to the exterior lamps
control.k(Dome Off):
Press the button
in and the dome lamps remain off
when a door is opened. Press the
button again to return it to the
extended position so that the dome
lamps come on when a door is
opened.
Reading Lamps
For vehicles with reading lamps,
they are located on the overhead
console.
To turn on the reading lamps, press
the button located next to each
lamp. To turn them off, press the
button again.
The vehicle may also have reading
lamps in other locations. To turn the
lamps on or off, press the button
located next to the lamp.
If the vehicle has a DVD Rear Seat
Entertainment (RSE) system, press
the lamp lenses to turn the lamps on
or off.
The lamps are fixed and cannot be
adjusted.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-9
Lighting Features
Entry Lighting
The vehicle has an illuminated entry
feature.
When the doors are opened, the
dome lamps will come on if the
dome override button is in the
extended position. If the dome
override button is pressed in, the
lamps will not come on.
Exit Lighting
The interior lamps come on when
the key is removed from the ignition.
They turn off automatically in
20 seconds. The lights do not come
on if the dome override button is
pressed in.
Battery Load
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery's temperature and state
of charge. It then adjusts the voltage
for best performance and extended
life of the battery.
When the battery's state of charge
is low, the voltage is raised slightly
to quickly bring the charge back up.
When the state of charge is high,
the voltage is lowered slightly to
prevent overcharging. If the vehicle
has a voltmeter gauge or a voltage
display on the Driver Information
Center (DIC), you may see the
voltage move up or down. This is
normal. If there is a problem, an
alert will be displayed.The battery can be discharged at
idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fast
enough at idle to produce all of
the power needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator's output
and the vehicle's electrical needs.
It can increase engine idle speed to
generate more power whenever
needed. It can temporarily reduce
the power demands of some
accessories.

Black plate (10,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-10 Lighting
Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,
this action may be noticeable to the
driver. If so, a DIC message might
be displayed, such as BATTERY
SAVER ACTIVE, BATTERY
VOLTAGE LOW, or LOW BATTERY.
If one of these messages displays, it
is recommended that the driver
reduce the electrical loads as much
as possible. SeeDriver Information
Center (DIC) on page 5‑30.Battery Power Protection
This feature shuts off the dome and
reading lamps, if they are left on for
more than 10 minutes after the
ignition is turned off. The cargo
lamp shuts off after 20 minutes.
This prevents the battery from
running down.

Black plate (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Infotainment System 7-7
EQ (Equalization):Press this
button to choose bass and treble
equalization settings designed for
different types of music. Selecting
MANUAL, or changing bass or
treble, returns the EQ to the manual
bass and treble settings.
Unique EQ settings can be saved
for each source.
Setting the Tone (Bass/
Midrange/Treble) (All Except
AM-FM Radio and Radio
with CD)
BASS/MID/TREB (Bass, Midrange,
or Treble): To adjust the bass,
midrange, or treble:
1. Press the
fknob until the tone
control tabs display.
2. Highlight the desired tone control tab by doing one of the
following:
.Press thefknob.
.Press the softkey under the
desired tab. 3. Adjust the setting by doing one
of the following:
.Turn thefknob clockwise
or counterclockwise.
.Press the¨SEEK,
or
©SEEK.
.Press the\FWD,
or
sREV.
If a station's frequency is weak or if
there is static, decrease the treble.
To quickly adjust bass, midrange,
or treble to the middle position,
press the softkey positioned under
the BASS, MID, or TREB tab for
more than two seconds. A beep
sounds and the level adjusts to the
middle position. To quickly adjust all tone and
speaker controls to the middle
position, press the
fknob for more
than two seconds until a beep
sounds.
EQ (Equalization): Press this
button to choose bass and treble
equalization settings designed for
different types of music. Selecting
MANUAL, or changing bass or
treble, returns the EQ to the manual
bass and treble settings.
Unique EQ settings can be saved
for each source.
If the radio has a Bose
®audio
system, the EQ settings are either
MANUAL or TALK.

Black plate (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
7-8 Infotainment System
Adjusting the Speakers
(Balance/Fade) (AM-FM Radio
and AM-FM Radio with CD)
To adjust the balance or fade:
1. Press
`or press thefknob
until the speaker control label
displays.
2. To adjust the setting, do one of the following:
.Turn thefknob.
.Press either¨SEEK,
or
©SEEK.
.Press either\FWD,
or
sREV.
Adjusting the Speakers
(Balance/Fade) (All Except
AM-FM Radio and Radio
with CD)
BAL/FADE (Balance/Fade): To
adjust the balance or fade:
1. Press the
fknob until the
speaker control tabs display.
2. Highlight the desired speaker control tab by doing one of the
following:
.Press thefknob.
.Press the softkey under the
desired tab.
3. Adjust the setting by doing one of the following:
.Turn thefknob clockwise
or counterclockwise.
.Press the¨SEEK,
or
©SEEK.
.Press the\FWD,
or
sREV. To quickly adjust all speaker and
tone controls to the middle position,
press the
fknob for more than
two seconds.
If the Rear Seat Audio (RSA) is
turned on, the radio disables FADE
and mutes the rear speakers.
Radio Messages
Calibration Error: The audio
system has been calibrated
for the vehicle from the factory.
If Calibration Error displays, it
means that the radio has not been
configured properly for the vehicle
and it must be returned to your
dealer for service.
Locked or Loc: One of these
messages will display when the
THEFTLOCK
®system has locked
up the radio. Take the vehicle to
your dealer for service.
If any error occurs repeatedly or
if an error cannot be corrected,
contact your dealer.

Black plate (15,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Infotainment System 7-15
Fixed Mast Antenna
The fixed mast antenna can
withstand most car washes without
being damaged as long as it is
securely attached to the base.
If the mast becomes slightly bent,
straighten it out by hand. If the mast
is badly bent, replace it.
Occasionally check to make sure
the antenna is tightened to its base.
If tightening is required, tighten
by hand until fully seated plus
one quarter turn.
Satellite Radio Antenna
The XM Satellite Radio antenna is
located on the roof of the vehicle.
Keep the antenna clear of
obstructions for clear radio
reception.
If the vehicle has a sunroof, the
performance of the XM system
(if equipped) may be affected if the
sunroof is open.
Audio Players
CD Player
Care of the CD Player
Do not add any label to a CD.
It could get caught in the CD. If a
CD is recorded on a personal
computer and a description label is
needed, try labeling the top of the
recorded CD with a marking pen.
The use of CD lens cleaners is
not advised, due to the risk of
contaminating the lens of the CD
optics with lubricants internal to the
CD player mechanism.
Notice:If a label is added to a
CD, more than one CD is inserted
into the slot at a time, or an
attempt is made to play scratched
or damaged CDs, the CD player
could be damaged. While using
the CD player, use only CDs in
good condition without any label,
load one CD at a time, and keep the CD player and the loading slot
free of foreign materials, liquids,
and debris.
If an error displays, see
“CD Player
Messages” later in this section.Care of CDs
If playing a CD-R, the sound quality
can be reduced due to CD-R or
CD-RW quality, the method of
recording, the quality of the music
that has been recorded, and the
way the CD-R or CD-RW has been
handled. Handle them carefully.
Store CD-Rs or CD-RWs in their
original cases or other protective
cases and away from direct sunlight
and dust. The CD player scans the
bottom surface of the disc. If the
surface of a CD is damaged, such
as cracked, broken, or scratched,
the CD does not play properly or not
at all. Do not touch the bottom side
of a CD while handling it; this could
damage the surface. Pick up CDs
by grasping the outer edges or the
edge of the hole and the outer edge.