2004 GMC SONOMA headlamp

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.
3-14

Driving Uphill
Once you decide you can safely drive up the hill, you
need to take some special steps.
•Use a low gear and get a firm grip on the steering
wheel.
•Get a smooth start up the hill and try to maintain
your speed. Do not use more power than you
need, because you do not want your wheels to start
spinning or sliding.
•Try to drive straight up the hill if at all possible. If
the path twists and turns, you might want to find
another route.
{CAUTION:
Turning or driving across steep hills can be
dangerous. You could lose traction, slide
sideways, and possibly roll over. You could be
seriously injured or killed. When driving up
hills, always try to go straight up.
•Ease up on your speed as you approach the top of
the hill.
•Attach a flag to the vehicle to make you more
visible to approaching traffic on trails or hills.
•Sound the horn as you approach the top of the hill
to let opposing traffic know you are there.
•Use your headlamps even during the day. They
make you more visible to oncoming traffic.
{CAUTION:
Driving to the top (crest) of a hill at full speed
can cause an accident. There could be a
drop-off, embankment, cliff, or even another
vehicle. You could be seriously injured or
killed. As you near the top of a hill, slow down
and stay alert.
4-19

Here are some tips on night driving.
•Drive defensively.
•Do not drink and drive.
•Adjust your inside rearview mirror to reduce the
glare from headlamps behind you.
•Since you can not see as well, you may need to
slow down and keep more space between you
and other vehicles.
•Slow down, especially on higher speed roads. Your
headlamps can light up only so much road ahead.
•In remote areas, watch for animals.
•If you are tired, pull off the road in a safe place
and rest.
No one can see as well at night as in the daytime. But
as we get older these differences increase. A
50-year-old driver may require at least twice as much
light to see the same thing at night as a 20-year-old.
What you do in the daytime can also affect your
night vision. For example, if you spend the day in bright
sunshine you are wise to wear sunglasses. Your
eyes will have less trouble adjusting to night. But if you
are driving, do not wear sunglasses at night. They
may cut down on glare from headlamps, but they also
make a lot of things invisible.You can be temporarily blinded by approaching
headlamps. It can take a second or two, or even several
seconds, for your eyes to re-adjust to the dark. When
you are faced with severe glare (as from a driver
who does not lower the high beams, or a vehicle with
misaimed headlamps), slow down a little. Avoid
staring directly into the approaching headlamps.
Keep your windshield and all the glass on your vehicle
clean — inside and out. Glare at night is made much
worse by dirt on the glass. Even the inside of the glass
can build up a film caused by dust. Dirty glass makes
lights dazzle and flash more than clean glass would,
making the pupils of your eyes contract repeatedly.
Remember that your headlamps light up far less of a
roadway when you are in a turn or curve. Keep
your eyes moving; that way, it is easier to pick out dimly
lighted objects. Just as your headlamps should be
checked regularly for proper aim, so should your eyes
be examined regularly. Some drivers suffer from
night blindness — the inability to see in dim light — and
are not even aware of it.
4-28

{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO (carbon
monoxide) gas to get inside. CO could
overcome you and kill you. You can not see it
or smell it, so you might not know it is in your
vehicle. Clear away snow from around the
base of your vehicle, especially any that is
blocking your exhaust pipe. And check around
again from time to time to be sure snow does
not collect there.
Open a window just a little on the side of the
vehicle that is away from the wind. This will
help keep CO out.Run your engine only as long as you must. This saves
fuel. When you run the engine, make it go a little
faster than just idle. That is, push the accelerator
slightly. This uses less fuel for the heat that you get and
it keeps the battery charged. You will need a
well-charged battery to restart the vehicle, and possibly
for signaling later on with your headlamps. Let the
heater run for a while.
Then, shut the engine off and close the window almost
all the way to preserve the heat. Start the engine
again and repeat this only when you feel really
uncomfortable from the cold. But do it as little as
possible. Preserve the fuel as long as you can. To help
keep warm, you can get out of the vehicle and do
some fairly vigorous exercises every half hour or so until
help comes.
4-41

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the Outside of
Your Vehicle..............................................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specifications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under
the Hood....................................................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid.........................5-19
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-35
Power Steering Fluid.....................................5-35Windshield Washer Fluid................................5-36
Brakes........................................................5-37
Battery........................................................5-40
Jump Starting...............................................5-41
Rear Axle.......................................................5-46
Four-Wheel Drive............................................5-46
Front Axle......................................................5-47
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-49
One-Piece Front Turn Signal Lamps................5-51
Two-Piece Front Turn Signal Lamps................5-51
Center High-Mounted Stoplamp (CHMSL).........5-52
Taillamps.....................................................5-53
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Inflation - Tire Pressure.................................5-67
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Uniform Tire Quality Grading..........................5-71
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-72
Section 5 Service and Appearance Care
5-1

Tire Chains..................................................5-74
If a Tire Goes Flat........................................5-74
Changing a Flat Tire.....................................5-75
Compact Spare Tire......................................5-85
Appearance Care............................................5-86
Cleaning the Inside of Your Vehicle.................5-86
Care of Safety Belts......................................5-89
Weatherstrips...............................................5-89
Cleaning the Outside of Your Vehicle..............5-89
Sheet Metal Damage.....................................5-91
Finish Damage.............................................5-92
Underbody Maintenance................................5-92
Chemical Paint Spotting.................................5-92
Vehicle Care/Appearance Materials..................5-93Vehicle Identication......................................5-94
Vehicle Identification Number (VIN).................5-94
Service Parts Identification Label.....................5-94
Electrical System............................................5-94
Add-On Electrical Equipment..........................5-94
Headlamps..................................................5-95
Windshield Wiper Fuses................................5-95
Power Windows and Other Power Options.......5-95
Fuses and Circuit Breakers............................5-95
Capacities and Specications........................5-101
Section 5 Service and Appearance Care
5-2

Headlamps
One-Piece Composite Headlamp
System
1. Open the hood.
2. Remove the black retainer clips by lifting up.
3. Pull the headlamp assembly out.
4. Unplug the electrical connector.5. Turn the bulb assembly counterclockwise to remove
it from the headlamp assembly.
6. Put the new bulb into the bulb assembly and
reinstall it in the headlamp assembly by turning
it clockwise until it is tight.
7. Plug in the electrical connector.
8. Put the headlamp assembly back into the vehicle.
9. Install the two retaining clips.
10. Close the hood.
5-49

Two-Piece Composite Headlamp
System
1. Open the hood.
2. Remove the black retainer clips by lifting up.
3. Unplug the electrical connector.
4. Pull the headlamp lens assembly out.5. Turn the bulb assembly counterclockwise to remove
it from the headlamp assembly.
6. Put the new bulb into the bulb assembly and
reinstall it in the headlamp assembly by turning
it clockwise until it is tight.
7. Plug in the electrical connector.
8. Put the headlamp lens assembly back into the
vehicle.
9. Install the two retaining clips.
10. Close the hood.
5-50