2003 GMC SONOMA check engine

If the light continues toash, when it is safe to do so,stop
the vehicle.Find a safe place to park your vehicle. Turn
the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see“If the Light Is
On Steady”following. If the light is stillashing, follow the
previous steps, and see your dealer for service as soon
as possible.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. SeeFilling Your Tank on page 5-6. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. A loose or missing
fuel cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.Have you recently changed brands of fuel?
If so, be sure to fuel your vehicle with quality fuel. See
Gasoline Octane on page 5-4. Poor fuel quality will
cause your engine not to run as efficiently as designed.
You may notice this as stalling after start-up, stalling
when you put the vehicle into gear, misring, hesitation
on acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the
light to turn on.
If you experience one or more of these conditions,
change the fuel brand you use. It will require at least
one full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
your dealer can check the vehicle. Your dealer has
the proper test equipment and diagnostic tools tox any
mechanical or electrical problems that may have
developed.
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Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON or CHECK ENGINE light is on or not
working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your battery
has run down. The diagnostic system is designed to
evaluate critical emission control systems during normal
driving. This may take several days of routine driving.
If you have done this and your vehicle still does not pass
the inspection for lack of OBD system readiness, your
GM dealer can prepare the vehicle for inspection.
Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is
running. Canadian vehicles indicate pressure in kPa
(kilopascals).United States
Canada
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{CAUTION:
Don’t keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catchesre. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused
by a dangerously low oil level or other problems causing
low oil pressure.
Security Light
This light will come on
briey when you turn the
key toward START.
The light will stay on until
the engine starts.
If the lightashes, the Passlock
®system has entered a
tamper mode. If the vehicle fails to start, seePasslock®
on page 2-19.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
®
system. Your vehicle will not be protected by Passlock®,
and you should see your dealer.
Also, seeContent Theft-Deterrent on page 2-17for
additional information regarding the SECURITY light.
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Service Four-Wheel Drive Warning
Light
If you have this light,
it should come on briey
when you turn on the
ignition, as a check
to show you it is working.
The SERVICE 4WD light comes on to indicate that
there may be a problem with the four-wheel drive system
and service is required. Malfunctions can be indicated
by the system before any problem is apparent,
which may prevent serious damage to the vehicle.
This system is also designed to assist your service
technician in correctly diagnosing a malfunction.
Check Gages Warning Light
The CHECK GAGES
light will come on briey
when you are starting
the engine.
If this light comes and stays on while you are driving,
check your coolant temperature and engine oil pressure
gages to see if they are in the warning zones.
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Audio System(s)
Notice:Before you add any sound equipment to
your vehicle—like a tape player, CB radio, mobile
telephone or two-way radio—be sure you can
add what you want. If you can, it’s very important to
do it properly. Added sound equipment may
interfere with the operation of your vehicle’s engine,
Delphi Electronics radio or other systems, and
even damage them. Your vehicle’s systems may
interfere with the operation of sound equipment that
has been added improperly.
So, before adding sound equipment, check with
your dealer and be sure to check federal rules
covering mobile radio and telephone units.
Your audio system has been designed to operate easily
and to give years of listening pleasure. You will get the
most enjoyment out of it if you acquaint yourself with it
rst. Find out what your audio system can do and how to
operate all of its controls to be sure you’re getting the
most out of the advanced engineering that went into it.Your vehicle has a feature called Retained Accessory
Power (RAP). With RAP, you can play your audio
system even after the ignition is turned off. See
“Retained Accessory Power (RAP)”underIgnition
Positions on page 2-20.
Setting the Time for Radios without
Radio Data Systems (RDS)
Press and hold HR until the correct hour appears on the
display. Press and hold MN until the correct minute
appears on the display. To display the time with
the ignition off, press RECALL or HR/MN and the time
will be displayed for a few seconds. There is an
initial two-second delay before the clock goes into the
time-set mode.
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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’re driving, brake
normally but don’t 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.
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’s 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’s say the road is wet and you’re driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here’s 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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Driving in Water
Heavy rain can meanashooding, andood waters
demand extreme caution.
Find out how deep the water is before you drive through
it. If it’s deep enough to cover your wheel hubs, axles
or exhaust pipe, don’t try it—you probably won’t
get through. Also, water that deep can damage your
axle and other vehicle parts.
If the water isn’t too deep, drive slowly through it. At faster
speeds, water splashes on your ignition system and your
vehicle can stall. Stalling can also occur if you get your
tailpipe under water. And, as long as your tailpipe is
under water, you’ll never be able to start your engine.
When you go through water, remember that when your
brakes get wet, it may take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous.Deep water can sweep your vehicle
downstream and you and your passengers
could drown.If it’s only shallow water, it can
CAUTION: (Continued)
CAUTION: (Continued)
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over.Don’t drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-28for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be are 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.
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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’re ready. Try to be well rested. If you
must start when you’re not fresh—such as after a day’s
work—don’t plan to make too many miles thatrst
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’s ready to go. If it needs
service, have it done before starting out. Of course,
you’llnd experienced and able service experts in
GM dealerships all across North America. They’ll be
ready and willing to help if you need it.
Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservior 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’s 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?
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