2007 GMC SIERRA CLASSIC service

Radio Reception
You may experience frequency interference and
static during normal radio reception if items
such as cellphone chargers, vehicle convenience
accessories, and external electronic devices
are plugged into the accessory power outlet. If
there is interference or static, unplug the item from
the accessory power outlet.
AM
The range for most AM stations is greater than for
FM, especially at night. The longer range can
cause station frequencies to interfere with each
other. For better radio reception, most AM
radio stations will boost the power levels during
the day, and then reduce these levels during
the night. Static can also occur when things like
storms and power lines interfere with radio
reception. When this happens, try reducing the
treble on your radio.
FM Stereo
FM stereo will give the best sound, but FM signals
will reach only about 10 to 40 miles (16 to 65 km).
Tall buildings or hills can interfere with FM
signals, causing the sound to fade in and out.
XM™ Satellite Radio Service
XM™ Satellite Radio Service gives digital radio
reception from coast-to-coast in the 48 contiguous
United States, and in Canada. Just as with FM,
tall buildings or hills can interfere with satellite
radio signals, causing the sound to fade in and out.
In addition, traveling or standing under heavy
foliage, bridges, garages, or tunnels may cause
loss of the XM™ signal for a period of time.
The radio may display NO SIGNAL to indicate
interference.
Care of the Cassette Tape Player
A tape player that is not cleaned regularly
can cause reduced sound quality, ruined
cassettes, or a damaged mechanism. Cassette
tapes should be stored in their cases away
from contaminants, direct sunlight, and extreme
heat. If they are not, they may not operate properly
or may cause failure of the tape player.
350

A non-scrubbing action, wet-type cleaner which
uses a cassette with a fabric belt to clean the tape
head can be used. This type of cleaning cassette
will not eject on its own. A non-scrubbing
action cleaner may not clean as thoroughly as the
scrubbing type cleaner. The use of a
non-scrubbing action, dry-type cleaning cassette is
not recommended.
After the player is cleaned, press and hold the
eject button for ve seconds to reset the CLEAN
indicator. The radio will display --- or CLEANED to
show the indicator was reset.
Cassettes are subject to wear and the sound
quality may degrade over time. Always make sure
the cassette tape is in good condition before
the tape player is serviced.Care of Your CDs and DVDs
Handle CDs carefully. Store them in their original
cases or other protective cases and away from
direct sunlight and dust. The CD player scans the
bottom surface of the disc. If the surface of a
CD is damaged, such as cracked, broken,
or scratched, the CD will not play properly or not
at all. If the surface of a CD is soiled, take a
soft, lint free cloth or dampen a clean, soft cloth in
a mild, neutral detergent solution mixed with
water, and clean it. Make sure the wiping process
starts from the center to the edge.
Do not touch the bottom side of a CD while
handling it; this could damage the surface. Pick up
CDs by grasping the outer edges or the edge of
the hole and the outer edge.
Care of the CD and DVD Player
The use of CD lens cleaners for CDs is not
advised, due to the risk of contaminating the lens
of the CD optics with lubricants internal to the
CD mechanism.
352

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by
heavy braking — rather than keeping pace with
traffic. This is a mistake. The brakes may not have
time to cool between hard stops. The brakes
will wear out much faster if you do a lot of heavy
braking. If you keep pace with the traffic and
allow realistic following distances, you will
eliminate a lot of unnecessary braking. That means
better braking and longer brake life.
If your vehicle’s engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the engine stops, you will still have
some power brake assist. But you will use it
when you brake. Once the power assist is used
up, it may take longer to stop and the brake pedal
will be harder to push.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 468.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system
that will help prevent a braking skid.
When you start your engine and begin to drive
away, ABS will check itself. You may hear a
momentary motor or clicking noise while this test
is going on. This is normal.
If there is a problem
with ABS, this warning
light will stay on.
SeeAnti-Lock Brake
System Warning
Light on page 255.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP
problem, both the brake and ABS warning lights will
come on accompanied by a 10-second chime. The
lights and chime will come on each time the ignition
is turned on until the problem is repaired. See your
dealer for service.
361

If your vehicle is in cruise control when the TAS
begins to limit wheel spin, the cruise control will
automatically disengage. When road conditions
allow you to safely use it again, you may re-engage
the cruise control. SeeCruise Control on page 217.
When the traction off
light is on, the TAS is
off and will not limit
wheel spin. Adjust your
driving accordingly.
The traction off light will come on under the
following conditions:
The Traction Assist System is turned off,
either by pressing the TAS on/off button,
located on the instrument panel, or by turning
off the automatic engagement feature of
the TAS.
The transmission is in FIRST (1); TAS will not
operate in this gear. This is normal.
The vehicle is driven on an extremely rough
road. When the vehicle leaves the rough
surface, slows down or stops, the light will go
off and TAS will turn on again. This is normal.
A Traction Assist System, Anti-Lock Brake
System or engine-related problem has been
detected and the vehicle needs service.
If the vehicle has been driven with the TAS
system on for long periods of time, or if the
vehicle has gone through many several high
speed braking maneuvers the system may be
automatically disabled. The system will
automatically re-enable after approximately
two minutes of not using the brakes.
SeeTraction Off Light on page 256.
The Traction Assist System, as delivered from the
factory, will automatically come on whenever
you start your vehicle. To limit wheel spin,
especially in slippery road conditions, you should
always leave the system on. But you can turn
the TAS off if you ever need to. You should turn
the TAS off if your vehicle ever gets stuck in sand,
mud or snow and rocking the vehicle is required.
364

To reinstall the lower air dam, do the following:
1. Line up each
push-pin with its
intended retainer
and push the washer
portion of the
push-pin toward the
retainer until it
locks into place.
2. Push the at end of
the push-pin toward
the retainer until
it locks into place,
making sure each
is secure.Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary
maintenance and service work done. Check to
make sure all underbody shields, if the vehicle has
them, are properly attached. Be sure you read
all the information about your four-wheel-drive
vehicle in this manual. Is there enough fuel? Is the
spare tire fully inated? Are the uid levels up
where they should be? What are the local
laws that apply to off-roading where you will be
driving? If you do not know, you should check with
law enforcement people in the area. Will you be
on someone’s private land? If so, be sure to
get the necessary permission.
375

After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake
linings cleaned and checked. These substances
can cause glazing and uneven braking. Check the
body structure, steering, suspension, wheels,
tires, and exhaust system for damage. Also, check
the fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service
due to off-road use. Refer to the Maintenance
Schedule for additional information.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to
be impaired — by alcohol or drugs, with night
vision problems, or by fatigue.
Here are some tips on night driving.
Drive defensively.
Do not drink and drive.
Adjust the inside rearview mirror to reduce the
glare from headlamps behind you.
Since you cannot see as well, you may need
to slow down and keep more space between
you and other vehicles.
Slow down, especially on higher speed roads.
Your vehicle’s headlamps can light up only so
much road ahead.
In remote areas, watch for animals.
If you are tired, pull off the road in a safe
place and rest.
No one can see as well at night as in the daytime.
But as we get older these differences increase.
A 50-year-old driver may require at least twice as
much light to see the same thing at night as a
20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the
day in bright sunshine you are wise to wear
sunglasses. Your eyes will have less trouble
adjusting to night. But if you are driving, do not
wear sunglasses at night. They may cut down on
glare from headlamps, but they also make a
lot of things invisible.
391

Before changing lanes, check your mirrors.
Then use your turn signal.
Just before you leave the lane, glance quickly
over your shoulder to make sure there is not
another vehicle in your blind spot.
Once you are moving on the freeway, make
certain you allow a reasonable following distance.
Expect to move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your
exit, do not, under any circumstances, stop and
back up. Drive on to the next exit.
The exit ramp can be curved, sometimes quite
sharply. The exit speed is usually posted.
Reduce your speed according to your
speedometer, not to your sense of motion.
After driving for any distance at higher speeds,
you may tend to think you are going slower than
you actually are.Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested.
If you must start when you are not fresh — such as
after a day’s work — do not plan to make too
many miles that rst part of the journey. Wear
comfortable clothing and shoes you can easily
drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it
needs service, have it done before starting out.
Of course, you will nd experienced and able
service experts in GM dealerships all across
North America. They will be ready and willing to
help if you need it.
398

Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservoir
full? Are all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you
checked all levels?
Lamps:Are they all working? Are the lenses
clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough
for long-distance driving? Are the tires
all inated to the recommended pressure?
Weather Forecasts:What is the weather
outlook along your route? Should you
delay your trip a short time to avoid a major
storm system?
Maps:Do you have up-to-date maps?
Highway Hypnosis
Is there actually such a condition as highway
hypnosis? Or is it just plain falling asleep at the
wheel? Call it highway hypnosis, lack of
awareness, or whatever.
There is something about an easy stretch of road
with the same scenery, along with the hum of the
tires on the road, the drone of the engine, and the
rush of the wind against the vehicle that can make
you sleepy. Do not let it happen to you! If it does,
your vehicle can leave the road in less than a
second, and you could crash and be injured.
What can you do about highway hypnosis?
First, be aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated,
with a comfortably cool interior.
Keep your eyes moving. Scan the road ahead
and to the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service, or parking area and take a nap, get
some exercise, or both. For safety, treat
drowsiness on the highway as an emergency.
399