2000 GMC SONOMA ignition

2-43
The following does not apply to vehicles first sold in
Canada, and to some early production vehicles.
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.
3. To return to the automatic mode, push the DOME
OVERRIDE button four times within six seconds
(the 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 (If Equipped)
Use your fog lamps for better vision in foggy or misty
conditions. Your parking lamps or low
-beam headlamps
must be on for your fog lamps to work.
The fog lamp switch is on the instrument panel under
the lamps switch. Press the switch to turn the fog lamps
on. Press the switch again to turn them off. A light will
glow in the switch when the fog lamps are on.
The fog lamps will go off whenever your high
-beam
headlamps come on. When the high
-beam headlamps
go off, the fog lamps will come on again.

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Interior Lamps
Brightness Control
Turn the thumbwheel next to the headlamp switch up to
make your instrument panel lights brighter. Turn the
thumbwheel all the way up to turn on the interior lamps.
Illuminated Entry
Your vehicle is equipped with an illuminated entry feature.
When the doors are opened, the dome lamps will come
on if the DOME OVERRIDE button is in the ªoutº
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 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 ªoutº position.
Exit Lighting
With exit lighting, the interior lamps will come on when
you remove the key from the ignition to help you seewhile 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 ªoutº position.
Front Map Lamps (If Equipped)
If your vehicle has front map lamps, they are located
on the inside rearview mirror. They will automatically
come on for approximately 40 seconds when the
doors are unlocked with the 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 keyless
entry transmitter.
You can also turn the lamps on and off by pressing the
switch near each lamp.
Dome Lamps
The dome lamps will come on when you open the doors.
You can also turn the dome lamps on by turning the
thumbwheel, located next to the parking/headlamps
knob, all the way up to the top detent position.
In this position, the dome lamps will remain on
whether the doors are opened or closed.

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You can use the DOME OVERRIDE button, located
below the parking/headlamp knob, to set the dome
lamps to come on automatically when the doors are
opened, or to remain off. To turn the lamps off, press the
button into the ªinº position. With the button in this
position, the dome lamps will remain off when the doors
are open. To return the lamps to automatic operation,
press the button again and return it to the ªoutº position.
With the button in this position, the dome lamps will
come on when you open the door. This will override the
illuminated entry feature, unless you use your keyless
entry transmitter to unlock the vehicle.
Battery Run-Down 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 run
-down 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.
Mirrors
Inside Day/Night Rearview Mirror
Pull the tab under the mirror toward you to reduce glare
from headlamps behind you after dark. Push the tab
away from you for normal daytime operation.
Outside Manual Adjust Mirror
Adjust your outside mirrors so you can just see the side
of your vehicle.
You can fold them before entering a car wash. Pull the
mirrors in toward the vehicle. Push the mirrors back out
when finished.

2-55 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, the passenger air bag suppression
circuit and the crash sensing and diagnostic module. For
more information on the air bag system, see ªAir Bagº
in the Index.
This light will come on
when you start your vehicle,
and it will flash 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 inflate in a crash, or they
could even inflate 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 should flash for a few
seconds 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.

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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 inflate
even though the switch is off. If this ever
happens, don't let anyone whom the national
government has identified 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.
Charging System Indicator Light
The charging system light
will come on briefly 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.

2-58 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.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.
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 ªShift Lightº in the Index.

2-59 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.
United States CanadaThis 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. (See ªTowing Your Vehicleº
in the Index.)
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.

2-60 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. See
ªBrake System Warning Lightº earlier in this section.
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
United States Canada
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.
The ªProblems on the Roadº section of this manual
shows you what to do. See ªEngine Overheatingº in
the Index.