2008 GMC SIERRA ECU

Be sure the cargo is properly loaded.
If small heavy objects are placed on the roof, cut a
piece of 3/8 inch plywood to t inside the crossrails
and siderails to spread the load. Tie the plywood
to the siderail supports.
Tie the load to the crossrails or the siderail supports.
Use the crossrails only to keep the load from sliding.
To move a crossrail, lift the release lever, on both
sides of the rail, up to loosen it. Slide the crossrail to
the desired position balancing the force side to side.
Press the release lever on both sides of the rail,
down to tighten it. Try to slide the crossrail back and
forth slightly to be sure it is tight.
If you need to carry long items, move the crossrails
as far apart as they will go. Tie the load to the
crossrails and the siderails or siderail supports. Also
tie the load to the bumpers. Do not tie the load so
tightly that the crossrails or siderails are damaged.
After moving a crossrail, be sure it is securely locked
into the siderail.
Your vehicle has a Center High-Mounted Stoplamp
(CHMSL) located above the rear glass.
If items are loaded on the roof of the vehicle, care
should be taken not to block or damage the CHMSL unit.
Rear Seat Armrest
Your vehicle may have a rear seat armrest that contains
two cupholders. To access the cupholders, pull the
armrest down from the rear seatback.
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Airbag Readiness Light..................................3-38
Airbag Off Light............................................3-39
Passenger Airbag Status Indicator...................3-41
Charging System Light..................................3-43
Voltmeter Gage............................................3-43
Brake System Warning Light..........................3-44
Antilock Brake System Warning Light...............3-45
StabiliTrak
®Indicator Light..............................3-46
Engine Coolant Temperature Gage..................3-46
Tire Pressure Light.......................................3-47
Malfunction Indicator Lamp.............................3-48
Oil Pressure Gage........................................3-50
Oil Pressure Light.........................................3-51
Security Light...............................................3-52
Fog Lamp Light............................................3-52
Cruise Control Light......................................3-52
Highbeam On Light.......................................3-52
Four-Wheel-Drive Light..................................3-53
Tow/Haul Mode Light....................................3-53
Fuel Gage...................................................3-53
Low Fuel Warning Light.................................3-54Driver Information Center (DIC).......................3-54
DIC Operation and Displays
(With DIC Buttons)....................................3-55
DIC Operation and Displays
(Without DIC Buttons)................................3-60
DIC Warnings and Messages.........................3-63
DIC Vehicle Customization
(With DIC Buttons)....................................3-72
Audio System(s).............................................3-80
Setting the Clock..........................................3-81
Radio(s)......................................................3-84
Using an MP3 (Radio with CD or
Six-Disc CD Player).................................3-102
Using an MP3 (Radio with CD and
DVD Player)...........................................3-106
XM Radio Messages...................................3-111
Navigation/Radio System..............................3-112
Rear Seat Entertainment (RSE) System.........3-113
Rear Seat Audio (RSA)................................3-122
Theft-Deterrent Feature................................3-123
Audio Steering Wheel Controls......................3-124
Radio Reception.........................................3-125
Fixed Mast Antenna....................................3-126
XM™ Satellite Radio Antenna System............3-126
Section 3 Instrument Panel
3-2

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.
3-40

{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.
3-42

Security Light
For information regarding
this light and the vehicle’s
security system, see
Content Theft-Deterrent on
page 2-18.
Fog Lamp Light
The fog lamp light will
come on when the fog
lamps are in use.
The light will go out when the fog lamps are turned off.
SeeFog Lamps on page 3-20for more information.
Cruise Control Light
This light comes on
whenever you set the
cruise control.
The light goes out when the cruise control is turned off.
SeeCruise Control on page 3-14for more information.
Highbeam On Light
This light comes on when
the high-beam headlamps
are in use.
SeeHeadlamp High/Low-Beam Changer on page 3-11
for more information.
3-52

Channel Off Air:This channel is not currently in
service. Tune to another channel.
Channel Unavail:This previously assigned channel is
no longer assigned. Tune to another station. If this
station was one of the presets, choose another station
for that preset button.
No Artist Info:No artist information is available at this
time on this channel. The system is working properly.
No Title Info:No song title information is available
at this time on this channel. The system is working
properly.
No CAT Info:No category information is available at
this time on this channel. The system is working
properly.
No Information:No text or informational messages are
available at this time on this channel. The system is
working properly.
CAT Not Found:There are no channels available for
the selected category. The system is working properly.
XM TheftLocked:The XM receiver in the vehicle
could have previously been in another vehicle. For
security purposes, XM™ receivers cannot be swapped
between vehicles. If this message appears after
having your vehicle serviced, check with your
dealer/retailer.XM Radio ID:If tuned to channel 0, this message
alternates with the XM Radio eight digit radio ID label.
This label is needed to activate the service.
Unknown:If this message is received when tuned to
channel 0, there could be a receiver fault. Consult
with your dealer/retailer.
Check XM Receivr:If this message does not clear
within a short period of time, the receiver could have a
fault. Consult with your dealer/retailer.
XM Not Available:If this message does not clear
within a short period of time, the receiver could have a
fault. Consult with your dealer/retailer.
Navigation/Radio System
Your vehicle may have a navigation radio system.
The navigation system has built-in features intended to
minimize driver distraction. Technology alone, no
matter how advanced, can never replace your own
judgment. See the Navigation System manual for some
tips to help you reduce distractions while driving.
3-112

Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the
roof. Keep cargo in the cargo area as far
forward and low as possible.There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the load oor and
forward of the rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving
on the off-road terrain does not toss things
around.
You will nd other important information in this manual.
SeeLoading Your Vehicle on page 4-36andTires
on page 5-66.
4-14

Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a
supply of windshield washer uid, a rag, some winter
outer clothing, a small shovel, a ashlight, a red
cloth, and reective warning triangles. And, if you will be
driving under severe conditions, include a small bag
of sand, a piece of old carpet, or a couple of burlap bags
to help provide traction. Be sure you properly secure
these items in your vehicle.
Also seeTires on page 5-66.
Driving on Snow or Ice
Most of the time, those places where the tires meet the
road probably have good traction.
However, if there is snow or ice between the tires and
the road, you can have a very slippery situation.
You have a lot less traction, or grip, and need to be
very careful.What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on. But wet ice
can be even more trouble because it can offer the least
traction of all. You can get wet ice when it is about
freezing, 32°F (0°C), and freezing rain begins to fall.
Try to avoid driving on wet ice until salt and sand crews
can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
4-31