Page 153 of 556

Black plate (15,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
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.
Page 154 of 556
Black plate (16,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-16 Instruments and Controls
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Engine Coolant
Temperature Gauge
Metric
English
This gauge shows the engine
coolant temperature.
It also provides an indicator of how
hard the vehicle is working. During
a majority of the operation, the
gauge reads 100°C (210°F) or less.
If pulling a load or going up hills, it
is normal for the temperature to
fluctuate and go over the 113°C
(235°F) mark. If the gauge reaches
the 125°C (260°F) mark, it indicates
that the cooling system is working
beyond its capacity. See
Engine Overheating on
page 10‑22.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
Voltmeter Gauge
This gauge indicates the battery
voltage when the ignition is
turned on.
When the ignition is on, this gauge
indicates the battery voltage.
Page 155 of 556

Black plate (17,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
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.
Page 156 of 556

Black plate (18,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-18 Instruments and Controls
Passenger Safety Belt
Reminder Light
For vehicles equipped with the
passenger safety belt reminder
light, several seconds after the
engine is started, a chime sounds
for several seconds to remind the
front passenger to buckle their
safety belt. The passenger safety
belt light flashes and then stays on
solid until the belt is buckled. This
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
The system checks the airbag's
electrical system for possible
malfunctions. If the light stays on
it indicates there is an electrical
problem. The system check
includes the airbag sensor(s), the
pretensioners, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
see
Airbag System on page 3‑21.
The airbag readiness light comes on
solid for a few seconds when the
engine 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
without a crash. To help avoid
injury, have the vehicle serviced
right away.
Page 157 of 556

Black plate (19,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-19
If there is a problem with the airbag
system, a Driver Information Center
(DIC) message can also come on.
SeeAirbag System Messages on
page 5‑45 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 3‑29 for more information,
including important safety
information.
Page 158 of 556

Black plate (20,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-20 Instruments and Controls
United States
Canada 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.
Do not turn off the passenger
airbag unless the person sitting
there is in a risk group identified
by the national government. See
Airbag On-Off Switch on
page 3‑29for 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.
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 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 3‑29 for more
information, including important
safety information.
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Black plate (21,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
Instruments and Controls 5-21
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. SeeAirbag On-Off Switch
on page 3‑29.
The passenger airbag status
indicator is on the overhead
console. See Passenger Sensing
System on page 3‑32 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.
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.
Page 160 of 556

Black plate (22,1)GMC Sierra Owner Manual - 2012 - CRC - 11/15/11
5-22 Instruments and Controls
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
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 5‑39 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.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.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, to produce
a cleaner environment. This light
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 9‑26.