2004 GMC SONOMA brake

;(Parking Lamps):Turning the exterior lamps
control to this position turns on the parking lamps
together with the following:
•Sidemarker Lamps
•Taillamps
•License Plate Lamps
•Instrument Panel Lights
O(Headlamps):Turning the exterior lamps control to
this position turns on the headlamps, together with
the previously listed lamps and lights.
Automatic Headlamp System
When it is dark enough outside, your automatic
headlamp system will turn on your headlamps at the
normal brightness along with other lamps such as
the taillamps, sidemarker, parking lamps and the
instrument panel lights. The radio lights will also be dim.
Your vehicle is equipped with a light sensor on the
top of the instrument panel under the radio speaker grill.
Be sure it is not covered or the system will be on
whenever the ignition is on.
The system may also turn on your headlamps when
driving through a parking garage, heavy overcast
weather or a tunnel. This is normal.There is a delay in the transition between the daytime
and nighttime operation of the Daytime Running
Lamps (DRL) and the automatic headlamp systems so
that driving under bridges or bright overhead street
lights does not affect the system. The DRL and
automatic headlamp system will only be affected when
the light sensor sees a change in lighting lasting
longer than the delay.
To idle your vehicle with the automatic headlamp
system off, set the parking brake while the ignition is off.
Then start your vehicle. The automatic headlamp
system will stay off until you release the parking brake.
As with any vehicle, you should turn on the regular
headlamps when you need them.
You may be able to turn off your automatic headlamp
system. See “Daytime Running Lamps (DRL)” later
in this section for more information.
If you start your vehicle in a dark garage, the automatic
headlamp system will come on immediately. Once
you leave the garage, it will take approximately
one minute for the automatic headlamp system to
change to DRL if it is light outside. During that delay,
your instrument panel cluster may not be as bright
as usual. Make sure your instrument panel brightness
control is in the full bright position. See “Instrument
Panel Brightness Control” underInterior Lamps
on page 3-15.
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Lamps On Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on, the driver’s door
is opened and your ignition is in OFF, LOCK or
ACCESSORY. To turn the chime off, turn the control
counterclockwise or turn the instrument panel brightness
thumbwheel down to the fully dimmed position. In the
automatic mode, the headlamps turn off once the ignition
key is in OFF.
Daytime Running Lamps
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. Fully functional
daytime running lamps are required on all vehicles
first sold in Canada.The DRL system will make your headlamps come on
at reduced brightness when the following conditions
are met:
•The ignition is on,
•the exterior lamp control is in OFF,
•the sensor detects daytime light,
•an automatic transmission is not in PARK (P), and
•the parking brake is released.
When the DRL are on, only your headlamps will be on.
The taillamps, sidemarker and other lamps won’t be
on. The instrument panel won’t be lit up either.
When it begins to get dark, the headlamps will
automatically switch from DRL to the regular headlamps.
The DRL system on some vehicles may turn off
temporarily while the turn signals are activated.
To idle an automatic transmission vehicle with the DRL
off, put the transmission in PARK (P). To idle a
manual transmission vehicle with the DRL off, set the
parking brake. The DRL will stay off until you shift out of
PARK (P) or release the parking brake.
The following does not apply to vehicles sold in Canada.
3-13

Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The
light will stay on if your parking brake doesn’t release
fully. If it stays on after your parking brake is fully
released, it means you have a brake problem.
Your vehicle’s hydraulic brake system is divided into two
parts. If one part isn’t 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, there could be a brake
problem. Have your brake system inspected right away.This light should come on briefly when you turn the
ignition key to RUN. If it doesn’t come on then, have it
fixed so it will be ready to warn you if there’s a
problem.
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, the pedal may go closer to the
floor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing
Your Vehicle on page 4-45.
{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.
United States
Canada
3-27

Anti-Lock Brake System
Warning Light
With the anti-lock brake
system, this light will come
on when you start your
engine and may stay on for
several seconds. That’s
normal.
If the light stays on, or comes on when you’re driving,
your vehicle needs service. If the regular brake
system warning light isn’t on, you still have brakes, but
you don’t have anti-lock brakes. If the regular brake
system warning light is also on, you don’t have anti-lock
brakes and there’s a problem with your regular
brakes. SeeBrake System Warning Light on page 3-27.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If
the light doesn’t come on then, have it fixed so it will be
ready to warn you if there is a problem.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine is
too hot!
It means that your engine coolant has overheated. If
you have been operating your vehicle under normal
driving conditions, you should pull off the road, stop your
vehicle and turn off the engine as soon as possible.
SeeEngine Overheating on page 5-26for more
information.
United StatesCanada
3-28

Your Driving, the Road, and
Your Vehicle
Defensive Driving
The best advice anyone can give about driving is: Drive
defensively.
Please start with a very important safety device in your
vehicle: Buckle up. SeeSafety Belts: They Are for
Everyone on page 1-8.
Defensive driving really means “be ready for anything.”
On city streets, rural roads or freeways, it means
“always expect the unexpected.”
Assume that pedestrians or other drivers are going to
be careless and make mistakes. Anticipate what
they might do. Be ready for their mistakes.
Rear-end collisions are about the most preventable of
accidents. Yet they are common. Allow enough following
distance. It is the best defensive driving maneuver, in
both city and rural driving. You never know when
the vehicle in front of you is going to brake or turn
suddenly.
Defensive driving requires that a driver concentrate on
the driving task. Anything that distracts from the driving
task — such as concentrating on a cellular telephone call,
reading, or reaching for something on the floor — makesproper defensive driving more difficult and can even
cause a collision, with resulting injury. Ask a passenger to
help do things like this, or pull off the road in a safe place
to do them yourself. These simple defensive driving
techniques could save your life.Drunken Driving
Death and injury associated with drinking and driving is
a national tragedy. It is the number one contributor
to the highway death toll, claiming thousands of victims
every year.
Alcohol affects four things that anyone needs to drive a
vehicle:
•Judgment
•Muscular Coordination
•Vision
•Attentiveness.
Police records show that almost half of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was
drinking and driving. In recent years, more than
16,000 annual motor vehicle-related deaths have been
associated with the use of alcohol, with more than
300,000 people injured.
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{CAUTION:
Drinking and then driving is very dangerous.
Your reexes, perceptions, attentiveness and
judgment can be affected by even a small
amount of alcohol. You can have a serious — or
even fatal — collision if you drive after drinking.
Please do not drink and drive or ride with a
driver who has been drinking. Ride home in a
cab; or if you are with a group, designate a
driver who will not drink.
Control of a Vehicle
You have three systems that make your vehicle go
where you want it to go. They are the brakes, the steering
and the accelerator. All three systems have to do their
work at the places where the tires meet the road.
Sometimes, as when you are driving on snow or ice, it
is easy to ask more of those control systems than
the tires and road can provide. That means you can lose
control of your vehicle.
4-5

Braking
Braking action involvesperception timeand
reaction time.
First, you have to decide to push on the brake pedal.
That isperception time.Then you have to bring up your
foot and do it. That isreaction time.
Averagereaction timeis about 3/4 of a second. But that
is only an average. It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical condition, alertness, coordination
and eyesight all play a part. So do alcohol, drugs and
frustration. But even in 3/4 of a second, a vehicle moving
at 60 mph (100 km/h) travels 66 feet (20 m). That
could be a lot of distance in an emergency, so keeping
enough space between your vehicle and others is
important.
And, of course, actual stopping distances vary greatly
with the surface of the road (whether it is pavement
or gravel); the condition of the road (wet, dry, icy); tire
tread; the condition of your brakes; the weight of
the vehicle and the amount of brake force applied.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. Your brakes may not have time to cool
between hard stops. Your 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 engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your 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.
4-6

Anti-lock Brake System
Your vehicle has anti-lock brakes. ABS is an advanced
electronic braking system that will help prevent a
braking skid.
When you start your engine and begin to drive away,
your anti-lock brake system 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
the anti-lock brake system,
this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-28.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is what
happens with ABS:
A computer senses that wheels are slowing down. If
one of the wheels is about to stop rolling, the computer
will separately work the brakes at each front wheel
and at both rear wheels.
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