2008 GMC SIERRA service

Puddle Lamps
If your vehicle has puddle lamps, they come on when
the unlock button on the Remote Keyless Entry
(RKE) Transmitter is pressed. The lamps time out or
turn off once the engine is started.
Fog Lamps
-(Fog Lamps):If your vehicle has fog lamps, the
control is located next to the exterior lamps control
on the instrument panel, to the left of the steering
column.
The ignition must be in the ON/RUN position for the fog
lamps to come on.
Press the button to turn the fog lamps on or off. A light
will come on in the instrument panel cluster.
When the fog lamps are turned on, the parking lamps
automatically turn on.
When the headlamps are changed to high-beam, the
fog lamps also go off. When the high-beam headlamps
are turned off, the fog lamps will come on again.
Some localities have laws that require the headlamps to
be on along with the fog lamps.
Auxiliary Roof Mounted Lamp
If your vehicle has this feature, this button includes
wiring provisions for a dealer or a qualied service
center to install an auxiliary roof lamp.
This button is located on
the overhead console.
When the wiring is connected to an auxiliary roof
mounted lamp, pressing the bottom of the button will
activate the lamp and illuminate an indicator light at the
bottom of this button. Pressing the top of the button
will turn off the roof mounted lamp and indicator.
The emergency roof lamp circuit is fused at 30 amps,
so the total current draw of the attached lamps
should be less than this value. The attachment points
for the roof lamp circuits are two blunt cut wires located
above the overhead console, a dark green switched
power wire and a black ground wire.
For further information on roof mount emergency lamp
installation, please visit the GM Uptter website at
www.gmuptters.com or contact your dealer.
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EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels
of corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC)
message might be displayed, such as Battery Saver
Active or Service Battery Charging System. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. See
DIC Warnings and Messages on page 3-63.
Battery Run-Down Protection
This feature shuts off the dome and reading lamps, if
they are left on for more than 10 minutes after the
ignition is turned off. The cargo lamp shuts off
after 20 minutes. This prevents the battery from
running down.
Accessory Power Outlet(s)
Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone or CB radio.
The vehicle may have two accessory power outlets
located below the climate control system, or may have
one accessory power outlet and one cigarette lighter.
The cigarette lighter is designed to t only in the
receptacle closest to the driver.
There may be another accessory power outlet in the
rear cargo area. If the vehicle has a oor console, there
is an accessory power outlet inside the storage bin
and one on the rear of the oor console.
To use an accessory power outlet, remove the protective
cap. When not in use, always cover the accessory
power outlet with the protective cap.
Notice:Leaving electrical equipment plugged in for
an extended period of time while the vehicle is off
will drain the battery. Power is always supplied
to the outlets. Always unplug electrical equipment
when not in use and do not plug in equipment
that exceeds the maximum 20 ampere rating.
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Airbag Readiness Light
There is an airbag readiness light on the instrument
panel cluster, which shows the airbag symbol. The
system checks the airbag’s electrical system for
malfunctions. The light tells you if there is an electrical
problem. The system check includes the airbag
sensor, the pretensioners, the airbag modules, the
wiring and the crash sensing and diagnostic module.
For more information on the airbag system, seeAirbag
System on page 1-68.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
The light should go out
and the system is ready.
If the airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your
airbag system may not work properly. Have your vehicle
serviced right away.{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the airbag
readiness light stays on after you start your
vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-63for
more information.
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When you manually turn the right front passenger’s
airbag 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 to remind you that the airbag has been
turned off. This light will go off when you turn the airbag
on. SeeAirbag Off Switch on page 1-76for more on
this, including important safety information.
{CAUTION:
If the right front passenger’s airbag is turned
off for a person who is not in a risk group
identied 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
inate and help protect the person sitting there.
Do not turn off the passenger’s airbag unless
the person sitting there is in a risk group
identied by the national government. See
Airbag Off Switch on page 1-76for more on this,
including important safety information.
{CAUTION:
If the airbag readiness light ever comes on
when you have turned off the airbag, it means
that something may be wrong with the airbag
system. The right front passenger’s airbag
could inate even though the switch is off. If
this ever happens, do not let anyone whom the
national government has identied as a
member of a passenger airbag risk group sit in
the right front passenger’s position (for
example, do not secure a rear-facing child
restraint in the right front passenger’s seat)
until you have your vehicle serviced. See
Airbag Off Switch on page 1-76andAirbag
Readiness Light on page 3-38for more on this,
including important safety information.
If the word ON or the on symbol is lit, it means that the
right front passenger’s frontal airbag is enabled (may
inate). SeeAirbag Off Switch on page 1-76for more on
this, 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/retailer for service.
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{CAUTION:
Even though the passenger sensing system is
designed to turn off the right front passenger’s
frontal airbag if the system detects a rear-facing
child restraint, no system is fail-safe, and no
one can guarantee that an airbag will not deploy
under some unusual circumstance, even
though it is turned off. We recommend that
rear-facing child restraints be secured in the
rear seat, even if the airbag is off.
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’s frontal
airbag. SeePassenger Sensing System on page 1-80
for more on this, 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 passenger sensing
system. See your dealer/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-38for more on this, including
important safety information.
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Readings outside the normal operating range may 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.
You can only drive for a short time with the readings
outside the normal operating range. If you must
drive, turn off all unnecessary accessories.
Readings outside the normal operating range indicate a
possible problem in the electrical system. Have the
vehicle serviced as soon as possible.Brake System Warning Light
With the ignition on, the brake system warning light
will come on when you set the parking brake. If you
try to drive with the parking brake engaged, a chime
will sound when the vehicle speed is greater
than 5 mph (8 km/h).
Your vehicle’s hydraulic brake system is divided into
two parts. If one part is not working, the other part can
still work and stop you. For good braking, though,
you need both parts working well.
If the warning light comes on and a chime sounds there
could be a brake problem. Have your brake system
inspected right away.
This light may also come on due to low brake uid. See
Brakes on page 5-42for more information.
United States
Canada
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This light should come on briey when you turn the
ignition key to RUN. If it does not come on then, have it
xed so it will be ready to warn you if there is a
problem.
{CAUTION:
Your brake system may not be working properly
if the brake system warning light is on. Driving
with the brake system warning light on can lead
to an accident. If the light is still on after you
have pulled off the road and stopped carefully,
have the vehicle towed for service.
If the light comes on while you are driving, pull off the
road and stop carefully. You may notice that the pedal is
harder to push or may go closer to the oor. It may
take longer to stop. If the light is still on, have the vehicle
towed for service. SeeTowing Your Vehicle on
page 4-50.
Antilock Brake System Warning
Light
For vehicles with the
Antilock Brake System
(ABS), this light will come
on briey when you
start the engine.
That is normal. If the light does not come on then, have it
xed so it will be ready to warn you if there is a problem.
If the ABS light stays on, turn the ignition off, if the light
comes on when you are 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 still
stays on, or comes on again while you are driving, your
vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but you do
not have antilock brakes. If the regular brake system
warning light is also on, you do not have antilock brakes
and there is a problem with your regular brakes. See
Brake System Warning Light on page 3-44
For vehicles with a Driver Information Center (DIC), see
DIC Warnings and Messages on page 3-63for all
brake related DIC messages.
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StabiliTrak®Indicator Light
If equipped, this warning
light should come on
briey when the engine
is started.
If the warning light does not come on then, have it xed
so it will be ready to warn you if there is a problem. If
it stays on, or comes on when you are driving, there may
be a problem with your StabiliTrak
®system and your
vehicle may need service. When this warning light is on,
the system is off and will not limit wheel spin. Adjust
your driving accordingly.
This light will also ash when the StabiliTrak
®system is
active.
If the StabiliTrak
®system warning light comes on and
stays on for an extended period of time when the system
is turned on, your vehicle needs service. See
StabiliTrak
®System on page 4-6for more information.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read 210°F (100°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
uctuate and go over the 235°F (113°C) mark. However,
if the gage reaches the 260°F (125°C) mark, it
indicates that the cooling system is working beyond its
capacity.
SeeEngine Overheating on page 5-30.
United StatesCanada
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