2012 GMC SIERRA 1500 sensor

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 (7,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-7
help quickly cool down the air
inside the vehicle. The light
on the button comes on in
recirculation.
2. Set the driver and passenger temperature.
To find your comfort setting, start
with a 23°C (74°F) temperature
setting and allow about
20 minutes for the system to
regulate. Use the driver or
passenger temperature buttons
to adjust the temperature setting
as necessary. If a temperature
setting of 15°C (60°F) is chosen,
the system remains at the
maximum cooling setting. If a
temperature setting of 32°C
(90°F) is chosen, the system
remains at the maximum heat
setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not cover the solar sensor
located on the top of the instrument
panel near the windshield. This sensor regulates air temperature
based on sun load. For more
information on the solar sensor, see
“Sensors”
later in this section.
To avoid blowing cold air in cold
weather, the system delays turning
the fan on until warm air is
available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch overrides this delay and
changes the fan to a selected
speed.
Manual Operation
D C(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and the
AUTO light turns off. The air
delivery mode remains under
automatic control.
H G(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display.
Pressing either mode button while
the system is off changes the air
delivery mode without turning the
system on.
Pressing either mode button while
in automatic control places the
mode under manual control. The air
delivery mode setting displays and
the AUTO light turns off. The fan
remains under automatic control.
H(Vent): Air is directed to the
instrument panel outlets.
)(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
toward the windshield and side
window outlets.

Black plate (9,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Climate Controls 8-9
This mode recirculates and helps
to quickly cool the air inside the
vehicle. It can be used to help
prevent outside air and odors from
entering the vehicle.
The recirculation mode cannot be
used with floor, defog, or defrost
modes. If recirculation is selected
with one of those modes, the
indicator light flashes three times
and then turns off. The air
conditioning compressor also comes
on when this mode is activated.
While in recirculation mode, the
windows may fog when the weather
is cold and damp. To clear the fog,
select either the defog or defrost
mode and increase the fan speed.
The recirculation mode can be
turned off by pressing the outside
air button, or by turning off the
ignition.
;(Outside Air):Press to turn the
outside air mode on. An indicator
light on the button comes on to
show that outside is on. When
selected, air from outside the vehicle circulates throughout the
vehicle. The recirculation mode
cannot be used with the outside
air mode.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
1(Rear Window Defogger):
For
vehicles with this feature, press
to turn the defogger on or off.
It automatically turns off several
minutes after it has been activated.
The defogger can also be turned off
by turning the engine off. Do not
drive the vehicle until all windows
are clear.
Notice: Do not use a razor blade
or sharp object to clear the inside
rear window. Do not adhere
anything to the defogger grid
lines in the rear glass. These
actions may damage the rear
defogger. Repairs would not be
covered by your warranty. Heated Mirror:
For vehicles with
heated outside rearview mirrors, the
mirrors heat to help clear fog or frost
from the surface of the mirror when
the rear window defog button is
pressed. See Power Mirrors on
page 2‑15.
Sensors
The solar sensor, located in the
defrost grille in the middle of the
instrument panel, monitors the solar
heat. Do not cover the solar sensor
or the system will not work properly.

Black plate (10,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
8-10 Climate Controls
The interior temperature sensor,
located in the headliner, measures
the temperature of the air inside the
vehicle.There is also an exterior
temperature sensor located behind
the front grille. This sensor reads
the outside air temperature and
helps maintain the temperature
inside the vehicle. Any cover on the
front of the vehicle could cause a
false reading in the displayed
temperature.
The climate control system uses the
information from these sensors to
maintain comfort settings by
adjusting the outlet temperature, fan
speed, and the air delivery mode.
The system may also supply cooler
air to the side of the vehicle facing
the sun. The recirculation mode will
also be used as needed to maintain
cool outlet temperatures.
Air Vents
Use the air outlets located in the
center and on the side of the
instrument panel to direct the
airflow. Use the thumbwheels near
the air outlets to open or close off
the airflow.
Operation Tips
.Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.
.Keep the path under the front
seats clear of objects to help
circulate the air inside of the
vehicle more effectively.
.Use of non‐GM approved hood
deflectors can adversely affect
the performance of the system.
Check with your dealer before
adding equipment to the outside
of the vehicle.

Black plate (61,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Driving and Operating 9-61
Object Detection
Systems
Ultrasonic Parking Assist
If available, the Ultrasonic Rear
Parking Assist (URPA) system
assists the driver with parking
and avoiding objects while in
R (Reverse). URPA operates at
speeds less than 8 km/h (5 mph).
The sensors on the rear bumper
detect objects up to 2.5 m (8 ft)
behind the vehicle, and at least
25 cm (10 in) off the ground.
{WARNING
The URPA system does not
detect pedestrians, bicyclists,
animals, or objects below the
bumper or that are too close or
too far from the vehicle. To
prevent injury, death, or vehicle
damage, even with URPA, always(Continued)
WARNING (Continued)
check the area around the vehicle
and check all mirrors before
backing.
How the System Works
URPA comes on automatically
when the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by audible
beeps. The interval between the
beeps becomes shorter as the
vehicle gets closer to the obstacle.
When the distance is less than
30 cm (12 in) the beeping is a
continuous tone for five seconds.
To be detected, objects must be at
least 25 cm (10 in) off the ground
and below tailgate level. Objects
must also be within 2.5 m (8 ft) from the rear bumper. This distance may
be less during warmer or humid
weather.
Turning the System On and Off
The URPA system can be turned
on and off using the rear park aid
disable button located next to the
radio.
The indicator light comes on when
the system is disabled and turns off
when the system is on.
When the system is off, PARK
ASSIST OFF displays on the Driver
Information Center (DIC). The
message disappears after a short
period of time.

Black plate (62,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
9-62 Driving and Operating
URPA defaults to the on setting
each time the vehicle is started.
Notice:If you use URPA while the
tailgate is lowered, it may not
detect an object behind your
vehicle, and you might back into
the object and damage your
vehicle. Always verify the tailgate
is closed when using URPA or
turn off URPA when driving with
the tailgate lowered.
When the System Does Not
Seem to Work Properly
The following messages may be
displayed on the DIC:
SERVICE PARK ASSIST: If this
message occurs, take the vehicle to
your dealer to repair the system. PARK ASST BLOCKED SEE
OWNERS MANUAL:
This
message can occur under the
following conditions:
.The ultrasonic sensors are not
clean. Keep the vehicle's rear
bumper free of mud, dirt, snow,
ice, and slush. For cleaning
instructions, see Exterior Care
on page 10‑98.
.The park assist sensors are
covered by frost or ice. Frost or
ice can form around and behind
the sensors and may not always
be seen; this can occur after
washing the vehicle in cold
weather. The message may not
clear until the frost or ice has
melted.
.A trailer was attached to the
vehicle, or an object was
hanging out of the tailgate during
the last drive cycle. Once the
object is removed and the
tailgate is raised, URPA will
return to normal operation.
.A tow bar is attached to the
vehicle.
.The bumper is damaged. Take
the vehicle to your dealer to
repair the system.
.Other conditions, such as
vibrations from a jackhammer or
the compression of air brakes on
a very large truck, are affecting
system performance.
Rear Vision
Camera (RVC)
If available, the Rear Vision Camera
(RVC) system displays part of the
scene behind the vehicle.
{WARNING
The RVC system does not display
pedestrians, bicyclists, animals,
or any other object located
outside the camera's field of view,
below the bumper, or under the
vehicle. Do not back the vehicle
(Continued)

Black plate (45,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-45
The Engine Compartment Fuse
Block is located in the engine
compartment, on the driver side of
the vehicle.
Lift the cover to access the fuse
block.
Notice:Spilling liquid on any
electrical component on the
vehicle may damage it. Always
keep the covers on any electrical
component.
To remove fuses, hold the end of
the fuse between your thumb and
index finger and pull straight out.
Fuses Usage
1 Right Trailer Stop/
Turn Lamp
2 Electronic Suspension
Control, Automatic Level
Control Exhaust
3 Left Trailer Stop/
Turn Lamp Fuses
Usage
4 Engine Controls
5 Engine Control Module,
Throttle Control
6 Trailer Brake Controller
7 Front Washer
8 Oxygen Sensor