ECU GMC SIERRA 2008 Workshop Manual

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

The GVWR includes the weight of the vehicle, all
occupants, fuel, and cargo.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR). To nd
out the actual loads on your front and rear
axles, you need to go to a weigh station and
weigh your vehicle. Your dealer can help you with
this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certication/Tire label also contains important
information about your Front Axle Reserve
Capacity. See “What is front axle reserve capacity,
and how do I calculate it?” underAdding a
Snow Plow or Similar Equipment on page 4-43.
{CAUTION:
In the case of a sudden stop or collision,
things carried in the bed of your truck
could shift forward and come into the
passenger area, injuring you and others. If
you put things in the bed of your truck,
you should make sure they are properly
secured.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
4-40

Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Using heavier suspension components to get
added durability might not change your weight
ratings. Ask your dealer to help you load
your vehicle the right way.
If you put things inside your vehicle — like
suitcases, tools, packages, or anything
else — they go as fast as the vehicle goes.
If you have to stop or turn quickly, or if there
is a crash, they will keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.
There is also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving“ underOff-Road
Driving on page 4-12.
4-41

Two-Tiered Loading
Depending on the model of your pick-up, you can
create an upper load platform by positioning
two or four 2 inches (5 cm) by 6 inches (15 cm)
wooden planks across the width of the pickup box.
The planks must be inserted in the pickup box
depressions. The length of the planks must allow
for at least a 3/4 inch (2 cm) bearing surface
on each end of the plank.
When using this upper load platform, be sure the
load is securely tied down to prevent it from
shifting. The load’s center of gravity should be
positioned in a zone over the rear axle. The zone
is located in the area between the front of each
wheel well and the rear of each wheel well.
The center of gravity height must not extend above
the top of the pickup box areboard.
Any load that extends beyond the vehicle’s
taillamp area must be properly marked according
to local laws and regulations.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.Add-On Equipment
When you carry removable items, you may need
to put a limit on how many people you carry
inside your vehicle. Be sure to weigh your vehicle
before you buy and install the new equipment.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the front or rear axle.
* Equipment Maximum Weight
Ladder Rack and
Cargo750 lbs (340 kg)
Cross Toolbox and
Cargo400 lbs (181 kg)
Side Boxes and Cargo 250 lbs per side
(113 kg per side)
* The combined weight for all rail-mounted
equipment should not exceed 1,000 lbs (454 kg).
4-42

Here are some guidelines for safely carrying a snow
plow on your vehicle:
Make sure the weight on the front and rear axles
does not exceed the axle rating for each.
For the front axle, if more cargo or passengers must
be carried, appropriate counter ballast must be
installed rear of the rear axle. Counter ballast must
be properly secured so it will not move during driving.
Follow the snow plow manufacturer’s
recommendations regarding rear ballast. Rear
ballast may be required to ensure a proper front and
rear weight distribution ratio, even though the actual
weight at the front axle may be less than the front
axle rating.
The snow plow manufacturer or installer can assist
you in determining the amount of rear ballast
required, to help make sure your snowplow/vehicle
combination does not exceed the GVW rating, the
front and rear axle ratings, and the front and rear
weight distribution ratio.
The total vehicle must not exceed the GVW rating.Front axle reserve capacity is the difference between
your front Gross Axle Weight Rating (GAWR) and the
front axle weight of your vehicle with full fuel and
passengers. Basically, it is the amount of weight you can
add to your front axle before reaching your front GAWR.
The front axle reserve capacity for your vehicle can be
found in the lower right corner of the Certication/Tire
label, as shown.
United States
Canada
4-44