2012 GMC SIERRA 1500 warning light

Black plate (25,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-25
The vehicle would be considered
not ready for inspection. This
can happen if the 12-volt battery
has recently been replaced or
run down. The diagnostic system
is designed to evaluate critical
emission control systems during
normal driving. This can take
several days of routine driving.
If this has been done and the
vehicle still does not pass the
inspection for lack of OBD II
system readiness, your dealer
can prepare the vehicle for
inspection.
Brake System Warning
Light
With the ignition on, the brake
system warning light comes on
when the parking brake is set. If the
vehicle is driven with the parking
brake engaged, a chime sounds
when the vehicle speed is greater
than 8 km/h (5 mph).The vehicle brake system consists
of two hydraulic circuits. If one
circuit is not working, the remaining
circuit can still work to stop the
vehicle. For normal braking
performance, both circuits need to
be working.
If the warning light comes on and a
chime sounds there could be a
brake problem. Have the brake
system inspected right away.
This light can also come on due to
low brake fluid. See
Brake Fluid on
page 10‑28 for more information.
MetricEnglish
This light comes on briefly when the
ignition key is turned to ON/RUN.
If it does not come on then, have it
fixed so it is ready to warn if there is
a problem.
{WARNING
The brake system might not be
working properly if the brake
system warning light is on.
Driving with the brake system
warning light on can lead to a
crash. If the light is still on after
the vehicle has been pulled off
the road and carefully stopped,
have the vehicle towed for
service.
If the light comes on while driving,
pull off the road and stop carefully.
The pedal might be harder to push
or might go closer to the floor. It can
take longer to stop. If the light is
still on, have the vehicle towed for
service. See Towing the Vehicle on
page 10‑93.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.

Black plate (26,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-26 Instruments and Controls
Antilock Brake System
(ABS) Warning Light
For vehicles with the Antilock Brake
System (ABS), this light comes on
briefly when the engine is started.
If it does not, have the vehicle
serviced by your dealer. If the
system is working normally the
indicator light then goes off.
If the ABS light stays on, turn the
ignition off. If the light comes on
while driving, stop as soon as it is
safely possible and turn the ignition
off. Then start the engine again to
reset the system. If the ABS light
stays on, or comes on again while
driving, the vehicle needs service.
If the regular brake system warning
light is not on, the vehicle still has
brakes, but not antilock brakes.If the regular brake system warning
light is also on, the vehicle does not
have antilock brakes and there is a
problem with the regular brakes.
See
Brake System Warning Light on
page 5‑25.
For vehicles with a Driver
Information Center (DIC), see Brake
System Messages on page 5‑40 for
all brake‐related DIC messages.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Four-Wheel-Drive Light
For vehicles equipped with the
four-wheel-drive light, it comes on
when a vehicle with a manual transfer case is shifted into
four-wheel drive and the front axle
engages.
Some delay between the shifting
and the light coming on is normal.
See
Four-Wheel Drive on page 9‑40
for more information.
Tow/Haul Mode Light
For vehicles with the Tow/Haul
Mode feature, this light comes on
when the Tow/Haul Mode has been
activated.
For more information, see Tow/Haul
Mode on page 9‑39.

Black plate (28,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-28 Instruments and Controls
When the Light Is On Steady
This indicates that one or more
of the tires are significantly
underinflated.
A Driver Information Center (DIC)
tire pressure message may also
display. SeeTire Messages on
page 5‑45. Stop as soon as
possible, and inflate the tires to the
pressure value shown on the Tire
and Loading Information label. See
Tire Pressure on page 10‑58.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light
will come on at every ignition
cycle. See Tire Pressure Monitor
Operation on page 10‑62.Engine Oil Pressure Light
Notice: Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine
oil low can also damage the
engine. The repairs would not be
covered by the vehicle warranty.
Check the oil level as soon as
possible. Add oil if required,
but if the oil level is within the
operating range and the oil
pressure is still low, have the
vehicle serviced. Always follow
the maintenance schedule for
changing engine oil.
This light comes on briefly while
starting the engine. If it does not,
have the vehicle serviced by your
dealer. If the system is working
normally the indicator light then
goes off. If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle
could be low on oil and it might
have some other system problem.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Low Fuel Warning Light
This light, under the fuel gauge,
comes on briefly while the engine is
being started.
This light and a chime, if the vehicle
is equipped with a radio, comes on
when the fuel tank is low on fuel.
The Driver Information Center also
displays a FUEL LEVEL LOW
message. See
Fuel System
Messages on page 5‑43 for more

Black plate (30,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-30 Instruments and Controls
Cruise Control Light
For vehicles equipped with cruise
control, this light comes on
whenever the cruise control is set.
The light goes out when the cruise
control is turned off. SeeCruise
Control on page 9‑58 for more
information.
Information Displays
Driver Information
Center (DIC)
The vehicle has a Driver Information
Center (DIC).
The DIC displays information about
this vehicle. It also displays warning
messages if a system problem is
detected.
All messages will appear in
the DIC display located below the
tachometer in the instrument panel
cluster.
The DIC comes on when the ignition
is on. After a short delay, the DIC
will display the information that was
last displayed before the engine
was turned off. The DIC has different displays
which can be accessed by pressing
the DIC buttons located on the
instrument panel, next to the
steering wheel. If the vehicle does
not have DIC buttons, the trip
odometer reset stem can be used to
access some of the menu items.
The DIC displays trip, fuel, and
vehicle system information, and
warning messages if a system
problem is detected.
The DIC also allows some features
to be customized. See
Vehicle
Personalization (With DIC Buttons)
on page 5‑48 for more information.
If the vehicle has a diesel
engine, see the Duramax
®diesel
supplement for more information.

Black plate (40,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-40 Instruments and Controls
SERVICE BATTERY
CHARGING SYSTEM
On some vehicles, this message
displays if there is a problem with
the battery charging system. Under
certain conditions, the charging
system light may also turn on in
the instrument panel cluster. See
Charging System Light on
page 5‑22. Driving with this problem
could drain the battery. Turn off all
unnecessary accessories. Have the
electrical system checked as soon
as possible. See your dealer.
Brake System Messages
SERVICE BRAKE SYSTEM
This message displays along with
the brake system warning light if
there is a problem with the brake
system. SeeBrake System Warning
Light on page 5‑25. If this message
appears, stop as soon as possible
and turn off the vehicle. Restart the
vehicle and check for the message
on the DIC display. If the message
is still displayed or appears again when you begin driving, the brake
system needs service as soon as
possible. See your dealer.
SERVICE BRAKES SOON
On some vehicles, this message
displays if there is a problem with
the brake system. If this message
appears, stop as soon as possible
and turn off the vehicle. Restart the
vehicle and check for the message
on the DIC display. If the message
is still displayed or appears again
when you begin driving, the brake
system needs service. See your
dealer.
SERVICE TRAILER BRAKE
SYSTEM
On vehicles with the Integrated
Trailer Brake Control (ITBC) system,
this message displays and a chime
may sound when there is a problem
with the ITBC system.
When this message displays, power
is no longer available to the trailer
brakes.
As soon as it is safe to do so,
carefully pull your vehicle over to
the side of the road and turn the
ignition off. Check the wiring
connection to the trailer and turn the
ignition back on. If this message still
displays, either your vehicle or the
trailer needs service. See your
dealer.
See
“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9‑94 for more
information.
Door Ajar Messages
DRIVER DOOR OPEN
This message displays and a chime
may sound if the driver door is not
fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.

Black plate (45,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-45
STABILITRAK OFF may also
display when the stability control
has been automatically disabled.
There are several conditions that
can cause this message to appear.
.One condition is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time.
.The message also displays if the
brake system warning light is on.
SeeBrake System Warning
Light on page 5‑25.
.The message could display if the
stability system takes longer
than usual to complete its
diagnostic checks due to driving
conditions.
.The message displays if an
engine or vehicle related
problem has been detected and
the vehicle needs service. See
your dealer. The message turns off as soon as
the conditions that caused the
message to be displayed are no
longer present.
Airbag System Messages
SERVICE AIR BAG
This message displays if there is a
problem with the airbag system.
Have your dealer inspect the
system for problems. See
Airbag
Readiness Light on page 5‑18 and
Airbag System on page 3‑21 for
more information.
Anti-theft Alarm System
Messages
SERVICE THEFT DETERRENT
SYSTEM
This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart so you may want to take the
vehicle to your dealer before turning off the engine. See
Immobilizer
Operation on page 2‑13 for more
information.
Starting the Vehicle
Messages
FAST IDLE ON
If your vehicle has this feature, this
message displays when the fast idle
feature is on. See Fast Idle System
on page 9‑29 for more information.
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
system is not working properly.
The tire pressure light also flashes
and then remains on during the
same ignition cycle. See Tire
Pressure Light on page 5‑27.

Black plate (46,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-46 Instruments and Controls
Several conditions may cause this
message to appear. SeeTire
Pressure Monitor Operation on
page 10‑62 for more information.
If the warning comes on and stays
on, there may be a problem with the
TPMS. See your dealer.
TIRE LEARNING ACTIVE
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays when the system
is re-learning the tire positions on
your vehicle. The tire positions must
be re-learned after rotating the tires
or after replacing a tire or sensor.
See Tire Inspection on page 10‑65,
Tire Rotation on page 10‑65, Tire
Pressure Monitor System on
page 10‑60, and Tire Pressure on
page 10‑58 for more information.
TIRE LOW ADD AIR TO TIRE
If the vehicle has the Tire Pressure
Monitor System (TPMS), this
message displays when the
pressure in one or more of the
vehicle's tires is low. This message also displays LEFT FRT (left front),
RIGHT FRT (right front), LEFT RR
(left rear), or RIGHT RR (right rear)
to indicate the location of the low
tire. The low tire pressure warning
light will also come on. See
Tire
Pressure Light on page 5‑27. You
can receive more than one tire
pressure message at a time. To
read the other messages that may
have been sent at the same time,
press the set/reset button or the
trip odometer reset stem. If a tire
pressure message appears on the
DIC, stop as soon as you can. Have
the tire pressures checked and set
to those shown on the Tire Loading
Information label. See Tires on
page 10‑50, Vehicle Load Limits on
page 9‑16, and Tire Pressure on
page 10‑58. The DIC also shows
the tire pressure values. See Driver
Information Center (DIC) on
page 5‑30.
Transmission Messages
SERVICE 4 WHEEL DRIVE
If the vehicle has four-wheel
drive, this message may display
if a problem occurs with the
four-wheel-drive system. If this
message appears, stop as soon as
possible and turn off the vehicle.
Make sure the key is in the LOCK/
OFF position for at least one minute
and then restart the vehicle and
check for the message on the DIC
display. If the message is still
displayed or appears again
when you begin driving, the
four-wheel-drive system needs
service. See your dealer.

Black plate (1,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Lighting 6-1
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . . 6-1
Exterior Lamps OffReminder . . . . . . . . . . . . . . . . . . . . 6-2
Headlamp High/Low-Beam Changer . . . . . . . . . . . . . . . . . . . . . 6-3
Flash-to-Pass . . . . . . . . . . . . . . . . . 6-3
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . 6-3
Automatic Headlamp System . . . . . . . . . . . . . . . . . . . . . . 6-4
Hazard Warning Flashers . . . . . 6-5
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . 6-5
Fog Lamps . . . . . . . . . . . . . . . . . . . . 6-6
Auxiliary Roof-Mounted Lamp . . . . . . . . . 6-6
Interior Lighting
Instrument Panel IlluminationControl . . . . . . . . . . . . . . . . . . . . . . 6-7
Cargo Lamp . . . . . . . . . . . . . . . . . . 6-8
Dome Lamps . . . . . . . . . . . . . . . . . 6-8
Reading Lamps . . . . . . . . . . . . . . . 6-8
Lighting Features
Entry Lighting . . . . . . . . . . . . . . . . . 6-9
Exit Lighting . . . . . . . . . . . . . . . . . . . 6-9
Battery Load Management . . . . 6-9
Battery Power Protection . . . . 6-10
Exterior Lighting
Exterior Lamp Controls
The exterior lamps control is located
on the instrument panel to the left of
the steering wheel.
It controls the following systems:
.Headlamps
.Taillamps
.Parking Lamps
.License Plate Lamps
.Instrument Panel Lights
.Roof Marker Lamps
(If Equipped)