service indicator GMC SIERRA 1500 2015 Owners Manual

Black plate (4,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
iv Introduction
Danger, Warnings, and
Cautions
{Danger
Text marked{Danger provides
information on risk of fatal injury.
Disregarding this information may
endanger life.
{Warning
Text marked{Warning provides
information on risk of accident or
injury. Disregarding this
information may lead to injury.
{Caution
Text marked{Caution provides
information that may indicate a
hazard that could result in injury
or death. It could also result in
possible damage to the vehicle.
A circle with a slash through it is a
safety symbol which means “Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: This symbol is shown when
you need to see your owner manual
for additional instructions or
information.
*: This symbol is shown when
you need to see a service manual
for additional instructions or
information.
Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. For more
information on the symbol, refer to
the Index.
0: Adjustable Pedals
9:Airbag Readiness Light
!:Antilock Brake System (ABS)

Black plate (30,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
3-30 Seats and Restraints
Warning (Continued)
Do not turn off the front outboard
passenger frontal airbag unless
the person sitting there is in a risk
group.
To turn off the front outboard
passenger frontal 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 front outboard passengerfrontal 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 front outboard
passenger frontal airbag is off. See
Airbag On-Off Light on page 5-18.
{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 front outboard
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
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.To turn the front outboard passenger
frontal airbag on again, insert the
ignition key into the switch, push in,
and move the switch to the on
position.
The front outboard passenger
frontal airbag is now enabled
(may inflate). See Airbag On-Off
Light on page 5-18.
Passenger Sensing
System
If the vehicle has one of the
following indicators, then the vehicle
has a passenger sensing system for
the front outboard passenger
position, unless there is an airbag
on-off switch on the instrument

Black plate (32,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
3-32 Seats and Restraints
Warning (Continued)
inflate under some unusual
circumstance, even though the
airbag is off.
Secure rear-facing child restraints
in a rear seat, even if the airbag
is off. If you secure a
forward-facing child restraint in
the front outboard passenger
seat, always move the seat as far
back as it will go. It is better to
secure the child restraint in a
rear seat.
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.
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag if:
.The front outboard passenger
seat is unoccupied.
.The system determines an infant
is present in a child restraint.
.A front outboard passenger
takes his/her weight off of the
seat for a period of time.
.There is a critical problem with
the airbag system or the
passenger sensing system.
When the passenger sensing
system has turned off the front
outboard passenger frontal airbag,
the off indicator will light and stay lit
as a reminder that the airbag is off.
See Passenger Airbag Status
Indicator on page 5-20.
The passenger sensing system is
designed to turn on the front
outboard passenger frontal airbag
anytime the system senses that a
person of adult size is sitting
properly in the front outboard
passenger seat.
When the passenger sensing
system has allowed the airbag to be
enabled, the on indicator will light
and stay lit as a reminder 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 front outboard passenger
frontal airbag, depending upon the
person's seating posture and body
build. Everyone in the 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.

Black plate (35,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Seats and Restraints 3-35
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. Topurchase a service manual, see
Service Publications Ordering
Information on page 13-11.
{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
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly. Theoperation of the airbag system can
also be affected by 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.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
In addition, the vehicle may have a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger 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

Black plate (14,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-14 Instruments and Controls
Fuel Gauge
Metric
EnglishWhen the ignition is on, the fuel
gauge indicates about how much
fuel is left in the tank.
There is an arrow near the fuel
gauge pointing to the side of the
vehicle the fuel door is on.
When the indicator nears empty, the
low fuel light comes on. There still is
a little fuel left, but the vehicle
should be refueled soon.
Here are four things that some
owners ask about. None of these
show a problem with the fuel gauge:
.At the service station, the fuel
pump shuts off before the gauge
reads full.
.It takes a little more or less fuel
to fill up than the gauge
indicated. For example, the
gauge may have indicated the
tank was half full, but it actually
took a little more or less than
half the tank's capacity to fill
the tank.
.The gauge moves a little while
turning a corner or speeding up.
.The gauge takes a few seconds
to stabilize after the ignition is
turned on, and goes back to
empty when the ignition is
turned off.

Black plate (17,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-17
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
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 may continue several times ifthe 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.
Passenger Safety Belt
Reminder Light
There may be a passenger safety
belt reminder light near the
passenger airbag status indicator.
See
Passenger Sensing System on
page 3-30.
For vehicles equipped with the
passenger safety belt warning light,
when the vehicle is started this light
flashes and a chime may come on
to remind passengers to fasten their
safety belt. Then the light stays on
solid until the belt is buckled. This

Black plate (18,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-18 Instruments and Controls
cycle continues several times if the
passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger safety belt is
buckled, neither the chime nor the
light comes on.
The front passenger safety belt
warning light and chime may turn on
if an object is put on the seat such
as a briefcase, handbag, grocery
bag, laptop, or other electronic
device. To turn off the warning light
and/or chime, remove the object
from the seat or buckle the
safety belt.
Airbag Readiness Light
This light shows if there is an
electrical problem with the airbag
system. The system check includes
the airbag sensor(s), passenger
sensing system (if equipped), the
pretensioners, the airbag modules,
the wiring, and the crash sensingand diagnostic module. For more
information on the airbag system,
see
Airbag System on page 3-21.
The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.
{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
(Continued)
Warning (Continued)
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 may also come on.
See Airbag System Messages on
page 5-41.
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.

Black plate (20,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-20 Instruments and Controls
Warning (Continued)
passenger frontal airbag could
inflate even though the airbag
on-off switch is turned off.
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 word ON or the on symbol is
lit, it means that the front outboard
passenger frontal airbag is enabled
(may inflate). See Airbag On-Off
Switch on page 3-28 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
following indicators, then the vehicle
has a passenger sensing system for
the front outboard passenger
position unless there is an airbag
on-off switch on the instrument
panel endcap. If there is an airbag
on-off switch, the vehicle does not
have a passenger sensing system.
See Airbag On-Off Switch on
page 3-28.
The passenger airbag status
indicator is on the overhead
console. See Passenger Sensing
System on page 3-30 for important
safety information.
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 front
outboard passenger frontal airbag.

Black plate (21,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Instruments and Controls 5-21
If the word ON or the on symbol is
lit on the passenger airbag status
indicator, it means that the front
outboard 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 front
outboard 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 5-18 for more
information, including important
safety information.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as a check to show the light is working.
It should go out when the engine is
started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging
system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a
message.
See
Battery Voltage and Charging
Messages on page 5-35.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.

Black plate (22,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
5-22 Instruments and Controls
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors the operation
of the vehicle to ensure emissions
are at acceptable levels, helping to
maintain a clean environment. The
malfunction indicator lamp comes
on when the vehicle is placed in
ON/RUN, as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer. See
Ignition Positions on page 9-24.
If the malfunction indicator lamp
comes on while the engine is
running, this indicates that the OBD
II system has detected a problem
and diagnosis and service might be
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 also
assists the service technician in
correctly diagnosing any
malfunction.
{Caution
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.
{Caution
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