light GMC SONOMA 2003 Owner's Guide

Heating
Turn the center knob clockwise or counterclockwise to
raise or lower the temperature on the inside of your
vehicle.
When it’s cold outside 0°F(−18°C) or lower, use the
engine coolant heater, if equipped, to provide warmer air
faster to your vehicle. An engine coolant heater warms
the coolant that the engine uses to provide heat to
warm the inside of your vehicle. For more information,
seeEngine Coolant Heater on page 2-24.
Cooling
On hot days, open the windows to let hot inside air
escape; then close them. This helps to reduce the time
it takes for your vehicle to cool down. It also helps
the system to operate more efficiently.
A/C (Air Conditioning):Turn the knob to the A/C
position to turn the air-conditioning system on or
off. When the system is on, this setting cools and
dehumidies the air entering your vehicle and directs
it through theoor outlets as well as the instrument
panel outlets.
MAX A/C (Maximum Air Conditioning):This mode
recirculates much of the air inside your vehicle so
it cools quickly. It directs most of the air through the
instrument panel outlets and a small amount through
theoor outlets.
-(Blend):Use this mode to direct half the air to the
windshield and half to theoor outlets. Close the
center outlets to help defrost the side windows more
quickly. In this mode, the system will automatically force
outside air into your vehicle and it will also run the
air-conditioning compressor, unless it falls below the
temperature at which air conditioning is effective.
You may notice a slight change in engine performance
when the air-conditioning compressor shuts off and
turns on again. This is normal. The system is designed
to make adjustments to help with fuel economy while
still maintaining the selected temperature.
For quick cool down on hot days, do the following:
1. Select A/C.
2. Select the coolest temperature.
3. Select the highest fan speed.
On cool, but sunny days, the sun may warm the upper
part of your body, but the lower part may not be
warm enough. To remedy this, do the following:
1. Select the bi-level mode.
2. Select the temperature.
3. Select the fan speed.
The air-conditioning system removes moisture from the
air, so you may sometimes notice a small amount of
water dripping underneath your vehicle while idling
or after turning off the engine. This is normal.
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2003 - Sonoma OM

Operation Tips

Clear away any ice, snow or leaves from the air
inlets at the base of the windshield that may
block theow of air into your vehicle.
Use of non-GM approved hood deectors may
adversely affect the performance of the system.
Keep the path under the front seats clear of objects
to help circulate the air inside of your vehicle more
effectively.
Warning Lights, Gages and
Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briey when you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly–and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
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2003 - Sonoma OM

Speedometer and Odometer
Your speedometer lets you see your speed in both
miles per hour (mph) and kilometers per hour (km/h).
Your odometer shows how far your vehicle has
been driven, in either miles (used in the United States)
or kilometers (used in Canada).
The odometer mileage can be checked without the
vehicle running. Simply press the trip odometer button.
You may wonder what happens if your vehicle needs
a new odometer installed. If the new one can be set to
the mileage total of the old odometer, then it must
be. But if it can’t, then it’s set at zero, and a label must
be put on the driver’s door to show the old mileage
reading when the new odometer was installed.
Trip Odometer
The trip odometer can tell you how far your vehicle has
been driven since you last set the trip odometer to zero.
To view the trip odometer, press the button near the
readout. To reset the trip odometer, hold the button until
it resets.
Tachometer
The tachometer (if equipped) displays the engine speed
in revolutions per minute (rpm).Notice:On vehicles with a manual transmission,
if you operate the engine with the tachometer in the
shaded warning areas, your vehicle’s engine or
other parts of your vehicle could be damaged.
Damage to your engine or vehicle caused by
operating the engine with the tachometer in the
shaded warning areas isn’t covered by your vehicle
warranty. Don’t operate the tachometer in the
shaded warning areas.
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
come on for several seconds to remind people to
fasten their safety belts, unless the driver’s safety belt is
already buckled.
The safety belt light will
also come on and stay
on for several seconds,
then it willash for
several more.
If the driver’s belt is already buckled, neither the chime
nor the light will come on.
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2003 - Sonoma OM

Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag’s electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, seeAir Bag System on page 1-54.
This light will come on
when you start your
vehicle, and it willash
for a few seconds.
Then the light should go
out. This means the
system is ready.
If the air bag readiness light stays on after you start the
vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help avoid
injury to yourself or others, have your vehicle
serviced right away if the air bag readiness light
stays on after you start your vehicle.
The air bag readiness light shouldash for a few
seconds when you turn the ignition key to RUN. If the
light doesn’t come on then, have itxed so it will
be ready to warn you if there is a problem.
Air Bag Off Light
When you turn the right front passenger’s air bag off,
this light will come on and stay on to remind you that the
air bag has been turned off. This light will go off when
you turn the air bag back on again. SeeAir Bag
Off Switch on page 1-60for more on this, including
important safety information.
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2003 - Sonoma OM

{CAUTION:
If the right front passenger’s air bag is turned
off for a person who isn’t in a risk group
identied by the national government, that
person won’t have the extra protection of an air
CAUTION: (Continued)
CAUTION: (Continued)
bag. In a crash, the air bag wouldn’t be able to
inate and help protect the person sitting there.
Don’t turn off the passenger’s air bag unless the
person sitting there is in a risk group identied
by the national government. See″Air Bag Off
Switch″in the Index for more on this, including
important safety information.
{CAUTION:
If the air bag readiness light ever comes on
when you have turned off the air bag, it means
that something may be wrong with the air bag
system. The right front passenger’s air bag
could inate even though the switch is off. If
this ever happens, don’t let anyone whom the
national government has identied as a member
of a passenger air bag risk group sit in the right
front passenger’s position (for example, don’t
secure a rear-facing child restraint in your
vehicle) until you have your vehicle serviced.
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2003 - Sonoma OM

Charging System Light
The charging system light
will come on briey when
you turn on the ignition,
but the engine is not
running, as a check to
show you it is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have a
problem with the charging system. It could indicate
that you have problems with a generator drive belt,
or another electrical problem. Have it checked
right away. Driving while this light is on could drain
your battery.
If you must drive a short distance with the light on,
be certain to turn off all your accessories, such as the
radio and air conditioner.
Voltmeter Gage
When your engine is not
running, but the ignition is
on (in RUN), this gage
shows your battery’s state
of charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power
at engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.
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2003 - Sonoma OM

You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Up-Shift Light
You have the shift light if
you have a manual
transmission.
Shifting when the indicator light is on will help you get
the best fuel economy. See“Up-Shift Light”under
Manual Transmission Operation on page 2-28.
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 briey when you turn the
ignition key to RUN. If it doesn’t come on then, have it
xed so it will be ready to warn you if there’s a problem.
United StatesCanada
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2003 - Sonoma OM

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
oor. It may take longer to stop. If the light is still on,
have the vehicle towed for service. SeeTowing
Your Vehicle on page 4-42.
{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’ve pulled off the road and stopped
carefully, have the vehicle towed for service.
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 briey when you turn the ignition key to RUN. If
the light doesn’t come on then, have itxed so it will be
ready to warn you if there is a problem.
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2003 - Sonoma OM

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 5-28for more
information.
Malfunction Indicator Lamp
Service Engine Soon Light in the
United States or Check Engine Light
in Canada
Your vehicle is equipped with a computer which
monitors operation of the fuel, ignition and emission
control systems.
This system is called OBD II (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the
life of the vehicle, helping to produce a cleaner
environment. United States
Canada
United StatesCanada
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2003 - Sonoma OM

The SERVICE ENGINE SOON or CHECK ENGINE light
comes on to indicate that there is a problem and
service is required. Malfunctions often will be indicated
by the system before any problem is apparent. This
may prevent more serious damage to your vehicle. This
system is also designed to assist your service
technician in correctly diagnosing any malfunction.
Notice:If you keep driving your vehicle with this
light on, after a while, your emission controls
may not work as well, your fuel economy may not
be as good and your engine may not run as
smoothly. This could lead to costly repairs that may
not be covered by your warranty.
Notice:Modications made to the engine,
transmission, exhaust, intake or fuel system of your
vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and may cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This may
also result in a failure to pass a required Emission
Inspection/Maintenance test.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn’t come on, have it repaired.This light will also come on during a malfunction in one of
two ways:
Light Flashing—Amisre condition has been
detected. A misre increases vehicle emissions and
may damage the emission control system on your
vehicle. Diagnosis and service may be required.
Light On Steady—An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
Avoiding steep uphill grades.
If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stopsashing and remains on steady, see
“If the Light Is On Steady”following.
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2003 - Sonoma OM