sensor GMC SIERRA 1500 2012 User Guide

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

Black plate (46,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-46 Vehicle Care
FusesUsage
9 Antilock Brakes System 2
10 Trailer Back-up Lamps
11 Driver Side Low-Beam
Headlamp
12 Engine Control Module
(Battery)
13 Fuel Injectors, Ignition
Coils (Right Side)
14 Transmission Control
Module (Battery)
15 Vehicle Back-up Lamps
16 Passenger Side
Low-Beam Headlamp
17 Air Conditioning
Compressor
18 Oxygen Sensors
19 Transmission Controls
(Ignition)
20 Fuel Pump
21 Fuel System Control
Module Fuses
Usage
22 Not Used
23 Not Used
24 Fuel Injectors, Ignition
Coils (Left Side)
25 Trailer Park Lamps
26 Driver Side Park Lamps
27 Passenger Side Park
Lamps
28 Fog Lamps
29 Horn
30 Passenger Side
High-Beam Headlamp
31 Daytime Running
Lamps (DRL)
32 Driver Side High-Beam
Headlamp
33 Daytime Running Lamps 2
34 Sunroof
35 Key Ignition System, Theft
Deterrent System Fuses
Usage
36 Windshield Wiper
37 SEO B2 Upfitter Usage
(Battery)
38 Electric Adjustable Pedals
39 Climate Controls (Battery)
40 Airbag System (Ignition)
41 Amplifier
42 Audio System
43 Miscellaneous (Ignition),
Cruise Control
44 Not Used
45 Airbag System (Battery)
46 Instrument Panel Cluster
47 Power Take-Off
48 Auxiliary Climate Control
(Ignition)
49 Center High-Mounted
Stoplamp (CHMSL)
50 Rear Defogger

Black plate (60,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-60 Vehicle Care
Tire Pressure for
High-Speed Operation
{WARNING
Driving at high speeds, 160 km/h
(100 mph) or higher, puts an
additional strain on tires.
Sustained high-speed driving
causes excessive heat buildup
and can cause sudden tire failure.
You could have a crash and you
or others could be killed. Some
high-speed rated tires require
inflation pressure adjustment for
high-speed operation. When
speed limits and road conditions
are such that a vehicle can be
driven at high speeds, make sure
the tires are rated for high-speed
operation, in excellent condition,
and set to the correct cold tire
inflation pressure for the
vehicle load.Vehicles with P265/70R17 or
P275/55R20 size tires require
inflation pressure adjustment when
driving the vehicle at speeds of
160 km/h (100 mph) or higher.
Set the cold tire inflation pressure
to 20 kPa (3 psi) above the
recommended cold tire pressure
shown on the Tire and Loading
Information label.
Return the tires to the
recommended cold tire inflation
pressure when high-speed driving
has ended. See
Vehicle Load Limits
on page 9‑16 andTire Pressure on
page 10‑58.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to a
receiver located in the vehicle. Each tire, including the spare
(if provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tire
pressure telltale when one or
more of your tires is significantly
under‐inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires
as soon as possible, and inflate
them to the proper pressure.

Black plate (62,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
10-62 Vehicle Care
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. See
Vehicle Load
Limits on page 9‑16.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires
are inflated to the correct inflation
pressure. If the vehicle has DIC
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, see Driver Information
Center (DIC) on page 5‑30 andTire
Messages on page 5‑45.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven.
This could be an early indicator that
the air pressure is getting low and
needs to be inflated to the proper
pressure. A Tire and Loading Information
label shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See
Vehicle Load
Limits on page 9‑16, for an example
of the Tire and Loading Information
label and its location. Also see Tire
Pressure on page 10‑58.
The TPMS can warn about a
low tire pressure condition but it
does not replace normal tire
maintenance. See Tire Inspection
on page 10‑65, Tire Rotation on
page 10‑65 andTires on
page 10‑50.
Notice: Tire sealant materials are
not all the same. A non-approved
tire sealant could damage the
TPMS sensors. TPMS sensor
damage caused by using an
incorrect tire sealant is not
covered by the vehicle
warranty. Always use only the
GM-approved tire sealant
available through your dealer or
included in the vehicle.

Black plate (63,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Vehicle Care 10-63
TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When the
system detects a malfunction, the
low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
.One of the road tires has been
replaced with the spare tire.
The spare tire does not have a
TPMS sensor. The malfunction
light and the DIC message
should go off after the road tire
is replaced and the sensor
matching process is performed
successfully. See "TPMS Sensor
Matching Process" later in this
section.
.The TPMS sensor matching
process was not done or
not completed successfully
after rotating the tires. The
malfunction light and the DIC
message should go off after
successfully completing the
sensor matching process. See
"TPMS Sensor Matching
Process" later in this section.
.One or more TPMS sensors
are missing or damaged. The
malfunction light and the DIC
message should go off when the
TPMS sensors are installed and
the sensor matching process is
performed successfully. See
your dealer for service.
.Replacement tires or wheels do
not match the original equipment
tires or wheels. Tires and wheels
other than those recommended
could prevent the TPMS from
functioning properly. SeeBuying
New Tires on page 10‑68.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly, it cannot detect or signal a
low tire condition. See your dealer
for service if the TPMS malfunction
light and DIC message come on
and stay on.
TPMS Sensor Matching
Process
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new
tire/wheel position after rotating the
vehicle’s tires or replacing one or
more of the TPMS sensors. Also,
the TPMS sensor matching
process should be performed after
replacing a spare tire with a road
tire containing the TPMS sensor.