headlamp GMC SIERRA 1500 2012 User Guide

Black plate (2,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-2 Lighting
The exterior lamps control has
four positions:
O(Off):Turns off the automatic
headlamps and Daytime Running
Lamps (DRL). Turn the headlamp
control to the off position again to
turn the automatic headlamps or
DRL back on.
For vehicles first sold in Canada,
the off position will only work when
the vehicle is shifted into P (Park).
AUTO (Automatic): Automatically
turns on the headlamps at normal
brightness, together with the
following:
.Parking Lamps
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps
(If Equipped)
When the vehicle is turned off and
the headlamps are in AUTO, the
headlamps may automatically
remain on for a set time. The time of the delay can be changed using the
DIC. See
Driver Information Center
(DIC) on page 5‑30
;(Parking Lamps): Turns on the
parking lamps together with the
following:
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps
(If Equipped)
2(Headlamps): Turns on the
headlamps together with the
following:
.Parking Lamps
.Instrument Panel Lights
.Taillamps
.License Plate Lamps
.Roof Marker Lamps (If
Equipped)
When the headlamps are turned
on while the vehicle is on, the
headlamps turn off automatically 10 minutes after the ignition is
turned off. When the headlamps are
turned on while the vehicle is off,
the headlamps will stay on for
10 minutes before automatically
turning off to prevent the battery
from being drained. Turn the
headlamp control to off and then
back to the headlamp on position to
make the headlamps stay on for an
additional 10 minutes.
Push the turn signal/multifunction
lever toward the instrument panel to
change the headlamps from low
beam to high beam.
Exterior Lamps Off
Reminder
For vehicles with a radio, a reminder
chime sounds when the headlamps
or parking lamps are manually
turned on, the ignition is off, and a
door is open. To disable the chime,
turn the lamp off.

Black plate (3,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-3
Headlamp High/
Low-Beam Changer
5 3
(Headlamp High/Low
Beam Changer): To change the
headlamps from low to high beam,
push the lever toward the instrument
panel. To return to low-beam
headlamps, pull the multifunction
lever toward you. Then release it.
When the high beams are on, this
indicator light on the instrument
panel cluster will also be on.
Flash-to-Pass
This feature lets you use the
high-beam headlamps to signal
a driver in front of you that you want
to pass. It works even if the
headlamps are in the automatic
position. To use it, pull the turn signal lever
toward you, then release it.
If the headlamps are in the
automatic position or on low
beam, the high-beam headlamps
will turn on. They will stay on as
long as you hold the lever toward
you. The high-beam indicator on the
instrument panel cluster will come
on. Release the lever to return to
normal operation.
Daytime Running
Lamps (DRL)
Daytime Running Lamps (DRL) can
make it easier for others to see the
front of your vehicle during the day.
Fully functional daytime running
lamps are required on all vehicles
first sold in Canada.
The DRL system comes on when
the following conditions are met:
.The ignition is on.
.The exterior lamps control is
in AUTO.
.The transmission is not in Park.
.The light sensor determines it is
daytime.
When the DRL system is on,
only the DRL lamps are on. The
taillamps, sidemarker, instrument
panel lights, and other lamps will not
be on.
When it begins to get dark, the
automatic headlamp system
switches from DRL to the
headlamps.
To turn off the DRL lamps, turn the
exterior lamps control to the OFF
position and then release. For
vehicles first sold in Canada, the
transmission must be in the P (Park)
position before the DRL lamps can
be turned off.

Black plate (4,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
6-4 Lighting
Automatic Headlamp
System
When it is dark enough outside, the
automatic headlamp system turns
on the headlamps at the normal
brightness, along with the taillamps,
sidemarker, parking lamps, and the
instrument panel lights. The radio
lights will also be dim.
To turn off the automatic headlamp
system, turn the exterior lamps
switch to the off position and then
release it. For vehicles first sold in
Canada, the transmission must be
in the P (Park) position before the
automatic headlamp system can be
turned off.
The vehicle has a light sensor
located on the top of the instrument
panel which regulates when the
automatic headlamps turn on. Do
not cover the sensor, otherwise the
headlamps will come on whenever
the ignition is on.
The system may also turn on the
headlamps when driving through a
parking garage or heavy overcast
weather. This is normal.
There is a delay in the transition
between the daytime and nighttime
operation of the Daytime Running
Lamps (DRL) and the automatic
headlamp systems so that driving
under bridges or bright overhead
street lights does not affect the
system. The DRL and automaticheadlamp system are only affected
when the light sensor detects a
change in lighting lasting longer
than the delay.
If the vehicle is started in a dark
garage, the automatic headlamp
system comes on immediately.
Once the vehicle leaves the garage,
it takes approximately one minute
for the automatic headlamp system
to change to DRL if it is bright
enough outside. During that delay,
the instrument panel cluster may not
be as bright as usual. Make sure the
instrument panel brightness control
is in the full bright position. See
Instrument Panel Illumination
Control on page 6‑7.
To idle the vehicle with the
automatic headlamp system off,
turn the control to the off position.
The headlamps will also stay on
after you exit the vehicle. This
feature can be programmed using
the Driver Information Center (DIC).
See
Vehicle Personalization (With
DIC Buttons) on page 5‑48.

Black plate (5,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-5
If the vehicle is not equipped
with DIC buttons, exit lighting is
automatic. When it is dark enough
outside, the exterior lamps remain
on for 30 seconds after the ignition
is moved from ON/RUN to
LOCK/OFF.
For vehicles without a radio, the
instrument panel light remains on for
30 seconds with the driver door
closed. For vehicles with a radio,
the instrument panel light remains
on for 10 minutes with the driver
door closed. SeeRetained
Accessory Power (RAP) on
page 9‑29.
The regular headlamp system can
be turned on when needed.Hazard Warning Flashers
|(Hazard Warning Flashers):
Press this button located on top of
the steering column, to make the
front and rear turn signal lamps
flash on and off. This warns others
that you are having trouble. Press
again to turn the flashers off.
When the hazard warning flashers
are on, the vehicle's turn signals will
not work.
Turn and Lane-Change
Signals
An arrow on the instrument panel
cluster flashes in the direction of the
turn or lane change.
Move the lever all the way up or
down to signal a turn.
Raise or lower the lever for less
than one second until the arrow
starts to flash to signal a lane
change. This causes the turn
signals to automatically flash
three times. It will flash six times
if tow-haul mode is active.

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 (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 (8,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-8 Driving and Operating
.Use headlamps even during the
day to make the vehicle more
visible.
{WARNING
Driving to the top of a hill at high
speed can cause an accident.
There could be a drop-off,
embankment, cliff, or even
another vehicle. You could be
seriously injured or killed. As you
near the top of a hill, slow down
and stay alert.
.Never go downhill forward
or backward with either the
transmission or transfer case in
N (Neutral). The brakes could
overheat and you could lose
control.
{WARNING
If the vehicle has the two‐speed
automatic transfer case, shifting
the transfer case to N (Neutral)
can cause your vehicle to roll
even if the transmission is in
P (Park). This is because the
N (Neutral) position on the
transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
.When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
{WARNING
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill:
1. Apply the brakes to stop the vehicle, and then apply the
parking brake.
2. Shift into P (Park) for an automatic transmission
or 1 (First) for a manual
transmission and then restart
the engine.
.If driving uphill when the
vehicle stalls, shift to
R (Reverse), release the
parking brake, and back
straight down.

Black plate (15,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-15
If it takes some time for help to
arrive, now and then when you run
the engine, push the accelerator
pedal slightly so the engine runs
faster than the idle speed. This
keeps the battery charged to restart
the vehicle and to signal for help
with the headlamps. Do this as little
as possible to save fuel.
If the Vehicle Is Stuck
Slowly and cautiously spin the
wheels to free the vehicle when
stuck in sand, mud, ice, or snow.
See“Rocking Your Vehicle to Get It
Out” later in this section.
If the vehicle has a traction system,
it can often help to free a stuck
vehicle. Refer to the vehicle's
traction system in the Index. If stuck
too severely for the traction system
to free the vehicle, turn the traction
system off and use the rocking
method.
{WARNING
If the vehicle's tires spin at high
speed, they can explode, and you
or others could be injured. The
vehicle can overheat, causing an
engine compartment fire or other
damage. Spin the wheels as little
as possible and avoid going
above 56 km/h (35 mph).
For information about using tire
chains on the vehicle, see Tire
Chains on page 10‑74.
Rocking Your Vehicle to Get
It Out
Turn the steering wheel left and
right to clear the area around the
front wheels. For four-wheel-drive
vehicles, shift into Four‐Wheel High. For vehicles with StabiliTrak
®, turn
the traction control part of the
system off. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal while
shifting, and press lightly on the
accelerator pedal when the
transmission is in gear. Slowly
spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the
vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. Recovery
hooks can be used, if the vehicle
has them. If the vehicle does need
to be towed out, see Towing the
Vehicle on page 10‑93.

Black plate (67,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-67
Reverse this procedure to reinstall
the RVC and make sure the
grommet and connection are
secure.
When the System Does Not
Seem To Work Properly
The RVC system might not work
properly or display a clear image if:
.The RVC is turned off. See
“Turning the RVC System On or
Off”earlier in this section.
.It is dark.
.The sun or the beam of
headlamps is shining directly
into the camera lens.
.Ice, snow, mud, or anything else
builds up on the camera lens.
Clean the lens, rinse it with
water, and wipe it with a soft
cloth.
.The back of the vehicle is in
an accident, the position and
mounting angle of the camera
can change or the camera can
be affected. Be sure to have the
camera and its position and
mounting angle checked at your
dealer.
The RVC system display in the
rearview mirror may turn off or not
appear as expected due to one of
the following conditions. If this
occurs the left indicator light on the
mirror will flash.
.A slow flash may indicate a loss
of video signal, or no video
signal present during the reverse
cycle.
.A fast flash may indicate that
the display has been on for
the maximum allowable time
during a reverse cycle, or the
display has reached an Over
Temperature limit. The fast flash conditions are
used to protect the video
device from high temperature
conditions. Once conditions
return to normal the device will
reset and the green indicator will
stop flashing.
During any of these fault conditions,
the display will be blank and the
indicator will flash while the vehicle
is in R (Reverse) or until the
conditions return to normal.
Press and hold
zwhen the left
indicator light is flashing to turn off
the video display along with the left
indicator light.

Black plate (97,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-97
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are
installed in the underhood electrical
center, but the wires are not
connected. They should be
connected by your dealer or a
qualified service center. The fuse
and wire for the ITBC is factory
installed and connected if the
vehicle is equipped with an ITBC.
The fuse for the battery feed is not
required if the vehicle has an
auxiliary battery. If the vehicle does
not have an auxiliary battery, have
your dealer or authorized service
center install the required fuse.
If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, located at
the end of the shift lever. This will
boost the vehicle system voltage
and properly charge the battery.
If the trailer is too light for Tow/
Haul Mode, or the vehicle is not
equipped with Tow/Haul, turn on the headlamps as a second way to
boost the vehicle system and
charge the battery.
Camper/Fifth-Wheel Trailer Wiring
Package
The seven-wire camper harness is
located under the front edge of the
pickup box on the driver side of
the vehicle, attached to the frame
bracket. A connector must be
added to the wiring harness which
connects to the camper.
The harness contains the following
camper/trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed
.Dark Blue: Trailer Brake
If the vehicle is equipped with the
“Heavy-Duty Trailering”
option,
please refer to “Heavy-Duty Trailer
Wiring Package” earlier in this
section.
When the camper-wiring harness
is ordered without the heavy-duty
trailering package, a seven-wire
harness with a seven-pin connector
is located at the rear of the vehicle
and is tied to the vehicle's frame.