2003 GMC SONOMA ignition

The following does not apply to vehicles sold in Canada.
When necessary, you may turn off the automatic
headlamp system and the Daytime Running
Lamps (DRL) feature by following the steps below:
1. Turn the ignition to RUN.
2. Press the DOME OVERRIDE button four times
within six seconds. After the fourth press of the
button, a chime will sound informing you that
the system is off. The system will revert back to the
automatic on mode when the ignition is turned to
OFF and then to RUN again.
3. To return to the automatic mode, push the DOME
OVERRIDE button four times within six seconds
(a chime will sound), or turn the ignition to OFF and
then to RUN again.
As with any vehicle, you should turn on the regular
headlamp system when you need it.Fog Lamps
Your vehicle may be equipped with fog lamps. Use your
fog lamps for better vision in foggy or misty conditions.
Your parking lamps or headlamps must be on for
your fog lamps to work.
The fog lamp button is located on the instrument panel
near the lamp control.
Press the button to turn the fog lamps on. Press the
button again to turn them off. A light will glow in
the button when the fog lamps are on.
Fog lamps will go off whenever your high-beam
headlamps come on. When the high-beams go off,
the fog lamps will come on again.
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2003 - Sonoma OM

Interior Lamps
Instrument Panel Brightness
This feature controls the brightness of the instrument
panel lights.
It is located on the driver’s side of your instrument panel
next to the exterior lamps control.
Turn the thumbwheel up to make your instrument panel
lights brighter or down to dim them. Turn the
thumbwheel all the way up to turn on the interior lamps.
Entry Lighting
Your vehicle is equipped with an entry lighting feature.
When any door is opened, the dome lamps will
come on if the DOME OVERRIDE button is in the out
position. If your vehicle is equipped with remote keyless
entry and all the doors are closed, or the front door
handles are lifted and released, the lamps will stay on
for a short period of time and will turn off automatically.
If you use your remote keyless entry transmitter to
unlock the vehicle, the interior lights will come on for a
short time whether or not the DOME OVERRIDE
button is in the out position.
Exit Lighting
With exit lighting, the interior lamps will come on when
you remove the key from the ignition to help you
see while exiting the vehicle. These lights will stay on
for a short period of time and then will go out, if the
DOME OVERRIDE button is in the out position.
Front Map Lamps
If your vehicle is a Crew Cab®and has front map
lamps, they are located in the overhead console. For all
other vehicles that have this feature, they are located
on the inside rearview mirror. The front map lights
that are located on the inside rearview mirror will
automatically come on for approximately 40 seconds
when the doors are unlocked with the remote keyless
entry transmitter (if equipped) or until the ignition key is
turned to RUN or ACCESSORY. The lamps will also
stay on for approximately 40 seconds after you exit the
vehicle, unless you lock the doors with the remote
keyless entry transmitter.
You can also turn the lamps on and off by pressing the
switch near each lamp.
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2003 - Sonoma OM

Dome Lamp
The dome lamp will come on when you open any door.
You can also turn the dome lamps on by turning the
instrument panel brightness thumbwheel, located next to
the exterior lamps control, all the way up to the
second notch. In this position, the dome lamps will
remain on whether a door is opened or closed.
You can use the DOME OVERRIDE button, located
below the exterior lamps control, to set the dome lamps
to come on automatically when any door is opened,
or to remain off. To turn the lamps off, press the button
in. With the button in, the dome lamps will remain off
when any door is opened. To return the lamps to
automatic operation, press the button again and return
it to the out position. With the button in this position,
the dome lamps will come on when you open any door.
This will override the illuminated entry feature, unless
you use your remote keyless entry transmitter
(if equipped) to unlock the vehicle.
Battery Rundown Protection
This feature shuts off the dome, courtesy, vanity,
reading, glove box, cargo and underhood lamps if they
are left on for more than 20 minutes when the ignition
is off. This will keep your battery from running down.If the battery rundown protection shuts off the interior
lamps, it may be necessary to do one of the following to
return it to normal operation:
Shut off all lamps and close all doors, or
turn the ignition key to RUN.
Accessory Power Outlets
Your vehicle may be equipped with an accessory
power outlet.
With accessory power outlets you can plug in auxiliary
electrical equipment such as a cellular telephone or
CB radio.
There may be an accessory power outlet located near
the center of the vehicle on the lower part of the
instrument panel. A small cap must be pulled down to
access an accessory power outlet. When not using
an outlet be sure to cover it with the protective cap.
Notice:When using an accessory power outlet,
maximum electrical load must not exceed 20 amps.
Always turn off any electrical equipment when
not in use. Leaving electrical equipment on for
extended periods will drain your battery.
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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

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