service GMC SIERRA 1500 2012 User Guide

Black plate (29,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Seats and Restraints 3-29
other parts. The service manual
for your vehicle covers the need
to replace other parts.
.The vehicle has a crash sensing
and diagnostic module which
records information after a
crash. SeeVehicle Data
Recording and Privacy on
page 13‑19 andEvent Data
Recorders on page 13‑19.
.Let only qualified technicians
work on the airbag systems.
Improper service can mean that
an airbag system will not work
properly. See your dealer for
service.
Airbag On-Off Switch
If one of the switches pictured in the
following illustrations is located in
the glove box, the vehicle has an
airbag on-off switch that you can
use to manually turn on or off the
right front passenger airbag.
United States
Canada and Mexico If the vehicle does not have an
airbag off switch, it may have a
passenger sensing system. See
Passenger Sensing System on
page 3‑32.
This switch should only be turned to
the off position if the person in the
right front passenger position is a
member of a passenger risk
group identified by the national
government as follows:
Infant. An infant (less than 1 year
old) must ride in the front seat
because:
.My vehicle has no rear seat;
.My vehicle has a rear seat too
small to accommodate a
rear-facing infant seat; or
.The infant has a medical
condition which, according to
the infant's physician, makes it
necessary for the infant to ride in
the front seat so that the driver
can constantly monitor the
child's condition.

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Seats and Restraints 3-31
To turn off the right front passenger
airbag, insert the ignition key into
the switch, push in, and move the
switch to the off position.
The word OFF or the off symbol will
come on in the passenger airbag
status indicator located in the
overhead console to let you know
that the right front passenger airbag
is off, after the system check is
completed. The airbag off light will
come on and stay on to let you
know that the right front passenger's
airbag is off. SeeAirbag On-Off
Light on page 5‑19.
{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)
WARNING (Continued)
To help avoid injury to yourself or
others, have the vehicle serviced
right away. SeeAirbag Readiness
Light on page 5‑18 for more
information, including important
safety information.
United States
Canada and Mexico
To turn the right front passenger
airbag on again, insert the ignition
key into the switch, push in, and
move the switch to the on position.
The right front passenger frontal
airbag is now enabled (may inflate).
See Airbag On-Off Light on
page 5‑19 for more information.

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3-34 Seats and Restraints
The passenger sensing system is
designed to turn on (may inflate) the
right front passenger frontal airbag
anytime the system senses that a
person of adult size is sitting
properly in the right front
passenger seat.
When the passenger sensing
system has allowed the airbag to be
enabled, the on indicator will light
and stay lit to remind you that the
airbag is active.
For some children, including
children in child restraints, and for
very small adults, the passenger
sensing system may or may not
turn off the right front passenger
frontal airbag, depending upon the
person's seating posture and body
build. Everyone in your vehicle
who has outgrown child restraints
should wear a safety belt
properly—whether or not there is
an airbag for that person.{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. See Airbag Readiness
Light on page 5‑18 for more
information, including important
safety information.
If the On Indicator is Lit for a
Child Restraint
If a child restraint has been installed
and the on indicator is lit:
1. Turn the vehicle off.
2. Remove the child restraint from the vehicle. 3. Remove any additional items
from the seat such as blankets,
cushions, seat covers, seat
heaters, or seat massagers.
4. Reinstall the child restraint following the directions
provided by the child restraint
manufacturer and refer to
Securing Child Restraints
(Center Front Seat Position) on
page 3‑58 orSecuring Child
Restraints (Right Front Seat
Position) on page 3‑58 or
Securing Child Restraints (Rear
Seat Position) on page 3‑55.
5. If, after reinstalling the child restraint and restarting the
vehicle, the on indicator is still lit,
turn the vehicle off. Then slightly
recline the vehicle seatback
and adjust the seat cushion,
if adjustable, to make sure that
the vehicle seatback is not
pushing the child restraint into
the seat cushion.

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3-36 Seats and Restraints
Additional Factors Affecting
System Operation
Safety belts help keep the
passenger in position on the
seat during vehicle maneuvers
and braking, which helps the
passenger sensing system maintain
the passenger airbag status.
See“Safety Belts” and“Child
Restraints” in the Index for
additional information about the
importance of proper restraint use.
If the shoulder portion of the belt is
pulled out all the way, the child
restraint locking feature will be
engaged. This may unintentionally
cause the passenger sensing
system to turn the airbag off for
some adult size occupants. If this
happens, let the belt go back all the
way and start again.
A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such as
seat covers, seat heaters, and seat
massagers can affect how well the
passenger sensing system operates. We recommend that
you not use seat covers or other
aftermarket equipment except when
approved by GM for your specific
vehicle. See
Adding Equipment to
the Airbag-Equipped Vehicle on
page 3‑37 for more information
about modifications that can affect
how the system operates.
The on indicator may be lit if an
object, such as a briefcase,
handbag, grocery bag, laptop or
other electronic device, is put on an
unoccupied seat. If this is not
desired, remove the object from
the seat.
{WARNING
Stowing of articles under the
passenger seat or between the
passenger seat cushion and
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system. To
purchase a service manual, see
Service Publications Ordering
Information on page 13‑16.
{WARNING
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
(Continued)

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Seats and Restraints 3-37
WARNING (Continued)
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Q: Is there anything I might addto or change about the vehicle
that could keep the airbags
from working properly?
A: Yes. If you add things that
change your vehicle's frame,
bumper system, height, front end
or side sheet metal, they may
keep the airbag system from
working properly. Changing or
moving any parts of the front
seats, safety belts, the airbag
sensing and diagnostic module,
steering wheel, instrument
panel, roof-rail airbag modules,
ceiling headliner or pillar garnish
trim, overhead console, front sensors, side impact sensors,
or airbag wiring can affect the
operation of the airbag system.
In addition, the vehicle may have
a passenger sensing system
for the right front passenger's
position, which includes sensors
that are part of the passenger's
seat. The passenger sensing
system may not operate properly
if the original seat trim is
replaced with non-GM covers,
upholstery or trim, or with
GM covers, upholstery or
trim designed for a different
vehicle. Any object, such as an
aftermarket seat heater or a
comfort enhancing pad or
device, installed under or on top
of the seat fabric, could also
interfere with the operation of
the passenger sensing system.
This could either prevent proper
deployment of the passenger
airbag(s) or prevent the
passenger sensing system
from properly turning off the
passenger airbag(s). See
Passenger Sensing System on
page 3‑32.
If you have any questions
about this, you should contact
Customer Assistance before you
modify your vehicle. The phone
numbers and addresses for
Customer Assistance are in
Step Two of the Customer
Satisfaction Procedure in
this manual. See
Customer
Satisfaction Procedure (U.S.
and Canada) on page 13‑1 or
Customer Satisfaction
Procedure (Mexico) on
page 13‑3.
If the vehicle has rollover
roof-rail airbags, see Different
Size Tires and Wheels on
page 10‑70 for additional
important information.

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3-38 Seats and Restraints
Q: What if I added a snow plow?Will it keep the airbags from
working properly?
A: We have designed our airbag
systems to work properly under
a wide range of conditions,
including snow plowing with
vehicles that have the optional
Snow Plow Prep Package
(RPO VYU). But do not change
or defeat the snow plow's
“tripping mechanism.” If you do,
it can damage your snow plow
and your vehicle, and it may
cause an airbag inflation.
Q: Because I have a disability, I have to get my vehicle
modified. How can I find out
whether this will affect my
airbag system?
A: If you have questions, call
Customer Assistance. The
phone numbers and addresses
for Customer Assistance are
in Step Two of the Customer
Satisfaction Procedure in
this manual. See Customer Satisfaction Procedure (U.S.
and Canada) on page 13‑3
or
Customer Satisfaction
Procedure (Mexico) on
page 13‑3.
In addition, your dealer and the
service manual have information
about the location of the airbag
sensors, sensing and diagnostic
module and airbag wiring.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See
Airbag Readiness Light on
page 5‑18.
Notice: If an airbag covering is
damaged, opened, or broken, the
airbag may not work properly. Do
not open or break the airbag
coverings. If there are any
opened or broken airbag covers,
have the airbag covering and/or
airbag module replaced. For
the location of the airbags, see Where Are the Airbags? on
page 3‑23. See your dealer for
service.
Replacing Airbag System
Parts after a Crash
{WARNING
A crash can damage the
airbag systems in the vehicle.
A damaged airbag system
may not work properly and
may not protect you and your
passenger(s) in a crash, resulting
in serious injury or even death.
To help make sure the airbag
systems are working properly
after a crash, have them
inspected and any necessary
replacements made as soon as
possible.

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Seats and Restraints 3-39
If an airbag inflates, you will need to
replace airbag system parts. See
your dealer for service.
If the airbag readiness light stays on
after the vehicle is started or comes
on when you are driving, the airbag
system may not work properly. Have
the vehicle serviced right away.
SeeAirbag Readiness Light on
page 5‑18.Child Restraints
Older Children
Older children who have outgrown
booster seats should wear the
vehicle safety belts. The manufacturer's instructions that
come with the booster seat state the
weight and height limitations for that
booster. Use a booster seat with a
lap-shoulder belt until the child
passes the fit test below:
.Sit all the way back on the seat.
Do the knees bend at the seat
edge? If yes, continue. If no,
return to the booster seat.
.Buckle the lap-shoulder belt.
Does the shoulder belt rest on
the shoulder? If yes, continue.
If no, try using the rear safety
belt comfort guide. See
“Rear
Safety Belt Comfort Guides”
under Lap-Shoulder Belt on
page 3‑14 for more information.
If the shoulder belt still does not
rest on the shoulder, then return
to the booster seat.

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Seats and Restraints 3-63
WARNING (Continued)
To help avoid injury to yourself or
others, have the vehicle serviced
right away. SeeAirbag Readiness
Light on page 5‑18 for more
information, including important
safety information.
If the vehicle does not have a rear
seat that will accommodate a
rear-facing child restraint, a
rear-facing child restraint should not
be installed in the vehicle, even if
the airbag is off.
If the child restraint has the
LATCH system, see Lower Anchors
and Tethers for Children (LATCH
System) on page 3‑47 for how and
where to install the child restraint
using LATCH. If a child restraint is
secured using a safety belt and it
uses a top tether, see Lower
Anchors and Tethers for Children
(LATCH System) on page 3‑47 for
top tether anchor locations. Do not secure a child restraint in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top strap
must be anchored.
In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.
You will be using the lap-shoulder
belt to secure the child restraint in
this position. Follow the instructions
that came with the child restraint.
1. Move the seat as far back as it
will go before securing the
forward-facing child restraint. If you have no other choice but
to install a rear-facing child
restraint in this seat, make sure
the airbag is off once the child
restraint has been installed.
When the airbag off switch
has turned off the right front
passenger frontal airbag, the off
indicator in the airbag off light
should light and stay lit when
you start the vehicle. See
Airbag
On-Off Light on page 5‑19.
2. Put the child restraint on the seat.
3. Pick up the latch plate, and run the lap and shoulder portions of
the vehicle's safety belt through
or around the restraint. The child
restraint instructions will show
you how.

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Instruments and Controls 5-15
Engine Oil Pressure
Gauge
Metric
English
The engine oil pressure gauge
shows the engine oil pressure
in kPa (kilopascals) or psi (pounds
per square inch) when the engine is
running.
Oil pressure can vary with engine
speed, outside temperature and oil
viscosity, but if readings are outside
the normal operating range, the oil
pressure light comes on. See
Engine Oil Pressure Light on
page 5‑28 for more information. A reading outside the normal
operating range can be caused by a
dangerously low oil level or some
other problem causing low oil
pressure. Check the vehicle's
oil as soon as possible. See
“OIL
PRESSURE LOW STOP ENGINE”
under Engine Oil Messages on
page 5‑42 andEngine Oil on
page 10‑7.
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.
If the vehicle has a diesel engine,
see the Duramax diesel supplement
for more information.

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Instruments and Controls 5-17
When the engine is running, this
gauge shows the condition of the
charging system. The gauge can
transition from a higher to lower or a
lower to higher reading. This is
normal. If the vehicle is operating
outside the normal operating range,
the charging system light comes on.
SeeCharging System Light on
page 5‑22 for more information. The
voltmeter gauge may also read
lower when in fuel economy mode.
This is normal.
Readings outside the normal
operating range can also occur
when a large number of electrical
accessories are operating in the
vehicle and the engine is left idling
for an extended period. This
condition is normal since the
charging system is not able to
provide full power at engine idle. As engine speeds are increased,
this condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power.
The vehicle can only be driven for a
short time with the readings outside
the normal operating range. If the
vehicle must be driven, turn off all
accessories, such as the radio and
air conditioner.
Readings outside the normal
operating range indicate a possible
problem in the electrical system.
Have the vehicle serviced as soon
as possible.Safety Belt Reminders
Driver Safety Belt Reminder
Light
There is a driver safety belt
reminder light on the instrument
panel cluster.
When the vehicle is started, this
light flashes and a chime may come
on to remind the driver to fasten
their safety belt. Then the light stays
on solid until the belt is buckled.
This cycle my continue several
times if the driver remains or
becomes unbuckled while the
vehicle is moving.
If the driver safety belt is buckled,
neither the light nor the chime
comes on.