2009 GMC SIERRA 1500 sensor

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 rst 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 in the defroster grille that regulates
when the automatic headlamps turn on. Do not cover the
sensor or the headlamps will come on whenever the
ignition is on.
The system may also turn on the headlamps when
driving through a parking garage, heavy overcast
weather, or a tunnel. 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 automatic headlamp
system is 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 will come 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. SeeInstrument Panel Brightness
on page 3-20.
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). SeeDIC Vehicle
Customization (With DIC Buttons) on page 3-75.
The regular headlamp system can be turned on when
needed.
3-18

The passenger’s temperature setting can be set to
match the driver’s temperature setting by pressing the
PASS button and turning off the PASS indicator.
When the passenger’s temperature setting is set
different than the driver’s setting, the indicator on the
PASS button illuminates and both the driver side
and passenger side temperature displays are shown.
Automatic Operation
AUTO (Automatic):When automatic operation is active
the system controls the inside temperature, the air
delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display changes to
show the current temperature(s) and AUTO is lit on
the display. The current air delivery mode and fan
speed are also displayed for about 5 seconds.
When AUTO is selected, the air conditioning
operation and air inlet are automatically controlled.
The air conditioning compressor may run when the
outside temperature is above freezing. The air inlet
will normally be set to outside air. If it is hot outside,
the air inlet may automatically switch to the
recirculate mode to help quickly cool down the air
inside the vehicle. The light on the button comes on
in recirculation.2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a 74°F (23°C)
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 60°F (15°C)
is chosen, the system remains at the maximum
cooling setting. If a temperature setting of 90°F
(32°C) 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.
3-28

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.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 your comfort setting 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.
3-32

Airbag Readiness Light
The system checks the airbag’s electrical system for
possible malfunctions. If the light stays on it indicates
there is an electrical problem. The system check includes
the airbag sensor, the pretensioners, the airbag modules,
the wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-72.
The airbag readiness light
ashes for a few seconds
when the engine is started.
If the light does not come
on then, have it xed
immediately.{CAUTION:
If the airbag readiness light stays on after the
vehicle is started or comes on while driving, it
means the airbag system might not be working
properly. The airbags in the vehicle might not
inate in a crash, or they could even inate
without a crash. To help avoid injury, have the
vehicle serviced right away.
If there is a problem with the airbag system, an airbag
Driver Information Center (DIC) message can also come
on. SeeDIC Warnings and Messages on page 3-66
for more information.
3-37

Relearn Tire Positions
Your vehicle may have this display. To access this
display, the vehicle must be in P (Park). If your vehicle
has the Tire Pressure Monitor System (TPMS), after
rotating the tires or after replacing a tire or sensor, the
system must re-learn the tire positions. To re-learn the
tire positions, seeTire Pressure Monitor System on
page 5-79.SeeTire Inspection and Rotation on
page 5-84andDIC Warnings and Messages on
page 3-66for more information.
Relearn Remote Key
To access this display, the vehicle must be in P (Park).
This display allows you to match Remote Keyless
Entry (RKE) transmitters to your vehicle. To match an
RKE transmitter to your vehicle:
1. Press the trip odometer reset stem until RELEARN
REMOTE KEY displays.
2. Press and hold the trip odometer reset stem for
three seconds.
The message REMOTE KEY LEARNING ACTIVE
will display.3. Press and hold the lock and unlock buttons on
the rst transmitter at the same time for about
15 seconds.
On vehicles with memory recall seats, the rst
transmitter learned will match driver 1 and
the second will match driver 2.
A chime will sound indicating that the transmitter is
matched.
4. To match additional transmitters at this time, repeat
Step 3.
Each vehicle can have a maximum of eight
transmitters matched to it.
5. To exit the programming mode, you must cycle the
key to LOCK/OFF.
3-62

TIGHTEN GAS CAP
This message may display along with the check engine
light on the instrument panel cluster if the vehicle’s fuel
cap is not tightened properly. SeeMalfunction Indicator
Lamp on page 3-45. Reinstall the fuel cap fully. See
Filling the Tank on page 5-11. The diagnostic system can
determine if the fuel cap has been left off or improperly
installed. A loose or missing fuel cap allows fuel to
evaporate into the atmosphere. A few driving trips with
the cap properly installed should turn this light and
message off.
TIRE LEARNING ACTIVE
If your vehicle has the Tire Pressure Monitor System
(TPMS), this message displays when the system is
re-learning the tire positions on your vehicle. See “DIC
Operation and Displays (Without DIC Buttons)” earlier in
this section for more information. The tire positions must
be re-learned after rotating the tires or after replacing a
tire or sensor. SeeTire Inspection and Rotation on
page 5-84,Tire Pressure Monitor System on page 5-79,
andInflation - Tire Pressure on page 5-76for more
information.
TRACTION CONTROL OFF
If your vehicle has StabiliTrak, this message displays
when the Traction Control System (TCS) is turned
off. Adjust your driving accordingly. SeeStabiliTrak
®
System on page 4-6for more information.
TRAILER CONNECTED
On vehicles with the Integrated Trailer Brake Control
(ITBC) system, this message displays briey when a
trailer with electric brakes is rst connected to the vehicle.
This message clears itself after several seconds. This
message also clears if you acknowledge it. After this
message clears, the TRAILER GAIN/OUTPUT display
appears in the DIC.
See “TRAILER GAIN/OUTPUT” underDIC Operation and
Displays (With DIC Buttons) on page 3-53orDIC
Operation and Displays (Without DIC Buttons) on
page 3-59and “Integrated Trailer Brake Control System”
underTowing a Trailer on page 4-53for more
information.
3-74

Checking Coolant
The coolant surge tank is located in the engine
compartment on the passenger side of the vehicle.
SeeEngine Compartment Overview on page 5-16
for more information on location.
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant surge
tank. If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or
above the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system is
cool before this is done.
The coolant level should be at or above the
FULL COLD mark. If it is not, you may have a
leak in the cooling system.
If the vehicle has a low coolant sensor and the
LOW COOLANT LEVEL message comes on and
stays on, it means you are low on engine coolant.
See “LOW COOLANT LEVEL” underDIC Warnings
and Messages on page 3-66.
5-33

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
vehicle’s 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 inated to the ination
pressure recommended by the vehicle manufacturer
on the vehicle placard or tire ination pressure label.
(If your vehicle has tires of a different size than the
size indicated on the vehicle placard or tire ination
pressure label, you should determine the proper
tire ination 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 signicantly under-inated.
Accordingly, when the low tire pressure telltale
illuminates, you should stop and check your tires
as soon as possible, and inate them to the proper
pressure. Driving on a signicantly under-inated
tire causes the tire to overheat and can lead to tire
failure. Under-ination also reduces fuel efficiency
and tire tread life, and may affect the vehicle’s
handling and stopping ability.Please note that the TPMS is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to
maintain correct tire pressure, even if under-ination
has not reached the level to trigger illumination of
the TPMS low tire pressure telltale.
Your vehicle has also been equipped with a TPMS
malfunction indicator to indicate when the system is not
operating properly. The TPMS malfunction indicator is
combined with the low tire pressure telltale. When the
system detects a malfunction, the telltale will ash for
approximately one minute and then remain continuously
illuminated. This sequence will continue upon
subsequent vehicle start-ups as long as the malfunction
exists.
When the malfunction indicator is illuminated, the
system may not be able to detect or signal low tire
pressure as intended. TPMS malfunctions may occur
for a variety of reasons, including the installation of
replacement or alternate tires or wheels on the vehicle
that prevent the TPMS from functioning properly. Always
check the TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to ensure that
the replacement or alternate tires and wheels allow the
TPMS to continue to function properly.
SeeTire Pressure Monitor Operation on page 5-80for
additional information.
5-79