2000 GMC SONOMA key

2-42
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
headlamp system when you need it.
Lamps On Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on and your ignition
is in OFF, LOCK or ACCESSORY. To turn the chime
off, turn the knob all the way to the left or turn the
instrument panel dimmer down to the fully dimmed
position. In the automatic mode, the headlamps turn
off once the ignition key is in OFF.
Daytime Running Lamps (If Equipped)
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 lights are required on
all vehicles first sold in Canada.The DRL system will make your headlamps come on at
reduced brightness when:

the ignition is on,

the headlamp switch is in automatic headlamp mode,

the light 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) or set the
parking brake. 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.

2-44
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.

2-45
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.

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NOTICE:
Do not operate the engine with the tachometer in
the red range, or engine damage will occur.
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 briefly 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.
Safety Belt Reminder Light
When the key is turned to RUN or START, a chime will
come on for about eight 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 about 20 seconds, then
it will flash for about
55 seconds.
If the driver's belt is already buckled, neither the tone
nor the light will come on.

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.

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.

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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
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center 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 stops flashing and remains on steady, see
ªIf the Light Is On Steadyº following.
If the light continues to flash, 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 ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
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. See ªFilling Your Tankº in the Index. 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.