light GMC SIERRA 2011 Workshop Manual

Black plate (21,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-21
{WARNING
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 inflate in a
crash, or they could even inflate
without a crash. To help avoid
injury, have the vehicle serviced
right away.
If there is a problem with the airbag
system, a Driver Information Center
(DIC) message can also come on.
See Airbag System Messages on
page 5‑48 for more information.
Airbag On-Off Light
If the vehicle has an airbag on-off
switch, it also has a passenger
airbag status indicator located in the
overhead console.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
for on and off, will light for several
seconds as a system check. Then, after several more seconds,
the status indicator ON or OFF,
or either the on or off symbol, will
light to let you know the status of
the right front passenger frontal
airbag.
When the right front passenger
airbag is manually turned off using
the airbag on-off switch in the glove
box, the indicator light OFF or the
off symbol will come on and stay on
as a reminder that the airbag has
been turned off. This light will go off
when the airbag has been turned
on. See
Airbag On-Off Switch on
page 3‑37 for more information,
including important safety
information.

Black plate (22,1)GMC Sierra Owner Manual - 2011
5-22 Instruments and Controls
United StatesCanada and Mexico
{WARNING
If the right front passenger airbag
is turned off for a person who is
not in a risk group identified by
the national government, that
person will not have the extra
protection of an airbag. In a
crash, the airbag will not be able
to inflate and help protect the
person sitting there.(Continued)
WARNING (Continued)
Do not turn off the passenger
airbag unless the person sitting
there is in a risk group identified
by the national government.
SeeAirbag On-Off Switch on
page 3‑37 for more on this,
including important safety
information.
{WARNING
If the airbag readiness light
ever comes on and stays on, it
means that something may be
wrong with the airbag system.
For example, the right front
passenger airbag could inflate
even though the airbag on-off
switch is turned off.
(Continued)

Black plate (23,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-23
WARNING (Continued)
To help avoid injury to yourself or
others, have the vehicle serviced
right away. SeeAirbag Readiness
Light on page 5‑20 for more
information, including important
safety information.
If the word ON or the on symbol
is lit, it means that the right front
passenger frontal airbag is enabled
(may inflate). See Airbag On-Off
Switch on page 3‑37 for more
information, including important
safety information.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the airbag
on-off switch. See your dealer for
service.
Passenger Airbag Status
Indicator
If the vehicle has one of the
indicators pictured in the following
illustrations, then the vehicle has
a passenger sensing system for
the right front passenger position
unless there is an airbag off switch
located in the glove box. If there
is an airbag off switch, the vehicle
does not have a passenger system
system. See Airbag On-Off Switch
on page 3‑37.
The passenger airbag status
indicator is on the overhead
console. See Passenger Sensing
System on page 3‑40 for important
safety information.
In addition, if the vehicle has a
passenger sensing system for the
right front passenger position, the
label on the vehicle's sun visor
refers to “ADVANCED AIRBAGS”.
United States
Canada and Mexico
When the vehicle is started, the
passenger airbag status indicator
will light ON and OFF, or the symbol
for on and off, for several seconds
as a system check. Then, after
several more seconds, the status
indicator will light either ON or OFF,
or either the on or off symbol to let
you know the status of the right front
passenger frontal airbag.

Black plate (24,1)GMC Sierra Owner Manual - 2011
5-24 Instruments and Controls
If the word ON or the on symbol is
lit on the passenger airbag status
indicator, it means that the right
front passenger frontal airbag is
enabled (may inflate).
If the word OFF or the off symbol is
lit on the airbag status indicator, it
means that the passenger sensing
system has turned off the right front
passenger frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be
a problem with the lights or the
passenger sensing system.
See your dealer for service.{WARNING
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light on page 5‑20 for more
information, including important
safety information.
Charging System Light
This light comes on briefly when
the ignition key is turned to START,
but the engine is not running, as a
check to show it is working. If it does not, have the vehicle
serviced by your dealer.
The light should go out once
the engine starts. If it stays on,
or comes on while driving, there
could be a problem with the
charging system. A charging system
message in the Driver Information
Center (DIC) can also appear.
See
Battery Voltage and Charging
Messages on page 5‑41 for more
information. This light could indicate
that there are problems with a
generator drive belt, or that there
is an electrical problem. Have it
checked right away. If the vehicle
must be driven a short distance with
the light on, turn off accessories,
such as the radio and air
conditioner.
For vehicles with a Hybrid, see
the Hybrid Supplement for more
information.

Black plate (25,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-25
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors operation of
the fuel, ignition, and emission
control systems. It ensures that
emissions are at acceptable levels
for the life of the vehicle, helping to
produce a cleaner environment.
This light should come on when the
ignition is on, but the engine is not
running, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer.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, after a while, 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.

Black plate (26,1)GMC Sierra Owner Manual - 2011
5-26 Instruments and Controls
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, when
it is safe to do so, stop the vehicle.
Find a safe place to 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. The following may correct an
emissions system malfunction:
.Make sure the fuel cap is
fully installed. See
Filling
the Tank on page 9‑88.
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 the light off.
.Make sure the electrical system
is not wet. The system could
be wet if the vehicle was driven
through a deep puddle of water.
The condition is usually
corrected when the electrical
system dries out. A few driving
trips should turn the light off.
.Make sure to fuel the vehicle
with quality fuel. Poor fuel quality
causes the engine not to run as
efficiently as designed and can
cause: stalling after start-up,
stalling when the vehicle is
changed into gear, misfiring,
hesitation on acceleration,
or stumbling on acceleration.
These conditions might go away
once the engine is warmed up.
If one or more of these
conditions occurs, change the
fuel brand used. It will require at
least one full tank of the proper
fuel to turn the light off.
See Recommended Fuel on
page 9‑84.
If none of the above have made
the light turn off, your dealer can
check the vehicle. The dealer
has the proper test equipment
and diagnostic tools to fix any
mechanical or electrical problems
that might have developed.

Black plate (27,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-27
Emissions Inspection and
Maintenance Programs
Some state/provincial and
local governments may have
programs to inspect the on-vehicle
emission control equipment.
For the inspection, the emission
system test equipment is connected
to the vehicle’s Data Link
Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. See your dealer if assistance
is needed.The vehicle may not pass
inspection if:
.The malfunction indicator lamp is
on with the engine running, or if
the light does not come on when
the ignition is turned to ON/RUN
while the engine is off.
.The critical emission control
systems have not been
completely diagnosed by
the system. This can happen
if the battery has recently
been replaced or if the battery
has run down. The diagnostic
system evaluates 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, 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.

Black plate (28,1)GMC Sierra Owner Manual - 2011
5-28 Instruments and Controls
This light can also come on due to
low brake fluid. SeeBrake Fluid on
page 10‑32 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 (Continued)
WARNING (Continued)
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 10‑103.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
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.

Black plate (29,1)GMC Sierra Owner Manual - 2011
Instruments and Controls 5-29
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.
SeeBrake System Warning Light on
page 5‑27.
For vehicles with a Driver
Information Center (DIC), see Brake
System Messages on page 5‑42 for
all brake related DIC messages.
For vehicles with a Hybrid, see
the Hybrid Supplement for more
information.Four-Wheel-Drive Light
The four-wheel-drive light
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 9‑54
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 9‑51.

Black plate (30,1)GMC Sierra Owner Manual - 2011
5-30 Instruments and Controls
StabiliTrak®Indicator
Light
For vehicles with the StabiliTrak
system, 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 while driving, there could be a
problem with the StabiliTrak system
and the vehicle might need service.
When this warning light is on, the
StabiliTrak system is off and does
not limit wheel spin. The light flashes if the system is
active and is working to assist the
driver with directional control of the
vehicle in difficult driving conditions.
See
StabiliTrak
®System on
page 9‑70 for more information.
If the vehicle is a hybrid, see
the hybrid supplement 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. When the Light is On Steady
This indicates that one or more
of the tires are significantly
underinflated.
A tire pressure message can
accompany the light. See
Tire
Messages on page 5‑49 for more
information. 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 10‑66
for more information.
When the Light Flashes First and
Then is On Steady
This indicates that there may be
a problem with the Tire Pressure
Monitor System. The light flashes
for about a minute and stays on
steady for the remainder of the
ignition cycle. This sequence
repeats with every ignition cycle.
See Tire Pressure Monitor
Operation on page 10‑69 for
more information.