2012 GMC SIERRA 1500 service

Black plate (23,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-23
If the malfunction indicator lamp
comes on and stays on while the
engine is running, this indicates that
there is an OBD II problem and
service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice:If the vehicle is
continually driven with this light
on, the emission controls might
not work as well, the vehicle fuel
economy might not be as good,
and the engine might not run as
smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty. Notice:
Modifications made
to the engine, transmission,
exhaust, intake, or fuel system
of the vehicle or the replacement
of the original tires with other
than those of the same Tire
Performance Criteria (TPC) can
affect the vehicle's emission
controls and can cause this light
to come on. Modifications to
these systems could lead to
costly repairs not covered by
the vehicle warranty. This could
also result in a failure to pass a
required Emission Inspection/
Maintenance test. See
Accessories and Modifications on
page 10‑3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required. To prevent more serious damage to
the vehicle:
.Reduce vehicle speed.
.Avoid hard accelerations.
.Avoid steep uphill grades.
.If towing a trailer, reduce the
amount of cargo being hauled as
soon as it is possible.
If the light continues to flash, stop
and park the vehicle. Turn the
vehicle off, wait at least 10 seconds,
and restart the engine. If the light is
still flashing, follow the previous
steps and see your dealer for
service as soon as possible.
Light On Steady: An emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.

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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.

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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.

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Instruments and Controls 5-27
StabiliTrak®OFF Light
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.
Press and release the Traction
Control System (TCS)/StabiliTrak
button to turn off TCS, and a
message displays in the DIC.
Press and briefly hold the TCS/
StabiliTrak button to turn off the
StabiliTrak system; the StabiliTrak
Off light comes on and a message
appears in the Driver Information
Center (DIC).If the StabiliTrak/TCS system is
off, the system does not assist in
controlling the vehicle. Turn on the
StabiliTrak/TCS system and the
indicator light turns off.
See
StabiliTrak
®System on
page 9‑55, and Ride Control System
Messages on page 5‑44 for more
information.
Traction Control System
(TCS)/StabiliTrak®Light
The TCS/StabiliTrak light comes on
briefly when the engine is started.
If the light does not come on or
stays on, have the vehicle serviced
by the dealer. If the system is
working normally, the indicator light
turns off. If the light comes on and stays
on while driving, and a message
displays in the Driver Information
Center (DIC), have the vehicle
serviced by the dealer. See
Ride
Control System Messages on
page 5‑44 for more information.
If the light flashes while driving, this
means that StabiliTrak or TCS is
assisting in controlling the vehicle.
See StabiliTrak
®System on
page 9‑55 for more information.
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine
is started. It provides information
about tire pressures and the TPMS.

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 (29,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-29
information. When fuel is added this
light and message should go off. If it
does not, have the vehicle serviced
by your dealer.
Security Light
The security light should come on
briefly as the engine is started. If the
system is working normally, the
indicator light turns off. If it does not
come on, have the vehicle serviced
by your dealer.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system.This light is also used to indicate the
status of the anti-theft alarm system
when the ignition is turned off. The
light will flash rapidly if the alarm
system is arming and one or more
of the monitored entry points is not
closed. The light will stay on if the
alarm is arming and all entry points
are closed.
For information regarding this light
and the vehicle's security system,
see
Anti-theft Alarm System on
page 2‑11.High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer on page 6‑3.
Front Fog Lamp Light
For vehicles with fog lamps, this
light comes on when the fog lamps
are on.
The light goes out when the fog
lamps are turned off. See Fog
Lamps on page 6‑6 for more
information.

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5-34 Instruments and Controls
Vehicle Information Menu
Items (with DIC Buttons)
T(Vehicle Information):Press
this button to scroll through the
following menu items:
Oil Life
Press the vehicle information
button until OIL LIFE REMAINING
displays. This display shows an
estimate of the oil's remaining useful
life. If you see 99% OIL LIFE
REMAINING on the display, that
means 99% of the current oil life
remains. The engine oil life system
will alert you to change the oil on a
schedule consistent with your
driving conditions.
When the remaining oil life is low,
the CHANGE ENGINE OIL SOON
message will appear on the display.
See “CHANGE ENGINE OIL SOON”
under Engine Oil Messages on
page 5‑42. You should change the
oil as soon as you can. See Engine
Oil on page 10‑7. In addition to the
engine oil life system monitoring the
oil life, additional maintenance is recommended in the Maintenance
Schedule in this manual. See
Maintenance Schedule on
page 11‑3
for more information.
Remember, you must reset the OIL
LIFE display after each oil change.
It will not reset itself. Also, be
careful not to reset the OIL LIFE
display accidentally at any time
other than when the oil has just
been changed. It cannot be reset
accurately until the next oil change.
To reset the engine oil life system,
see Engine Oil Life System on
page 10‑10.
Units
Press the vehicle information button
until UNITS displays. This display
allows you to select between metric
or English units of measurement.
Once in this display, press the set/
reset button to select between
METRIC or ENGLISH units. All of
the vehicle information will then
be displayed in the unit of
measurement selected. Tire Pressure
If the vehicle has the Tire Pressure
Monitor System (TPMS), the
pressure for each tire can be viewed
in the DIC. The tire pressure will be
shown in either kilopascals (kPa) or
pounds per square inch (psi). Press
the vehicle information button
until the DIC displays FRONT
TIRES kPa (PSI) LEFT ##
RIGHT ##. Press the vehicle
information button again until the
DIC displays REAR TIRES kPa
(PSI) LEFT ## RIGHT ##.
If a low tire pressure condition is
detected by the system while
driving, a message advising you to
add pressure in a specific tire will
appear in the display. See
Tire
Pressure on page 10‑58 andTire
Messages on page 5‑45 for more
information.
If the tire pressure display shows
dashes instead of a value, there
may be a problem with the vehicle.
If this consistently occurs, see your
dealer for service.

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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.