2003 GMC SONOMA battery

Automatic Transmission Operation
Your automatic transmission has a shift lever on the
steering column.
There are several different positions for your shift lever.
It features an electronic shift position indicator within
the instrument cluster. This display must be powered
anytime the shift lever is capable of being moved out of
PARK (P). This means that if your key is in OFF, but
not locked, there will be a small current drain on
your battery which could discharge your battery over a
period of time. If you need to leave your key in the
ignition in OFF for an extended period, it is
recommended that you disconnect the battery cable
from the battery to prevent discharging your battery.PARK (P):This position locks your rear wheels. It’s the
best position to use when you start your engine because
your vehicle can’t move easily.
{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brakefirmly set. Your vehicle can roll.
Don’t leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won’t move, even when you’re on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P). See“Shifting
Into Park (P)”in the Index. If you’re pulling a
trailer, see“Towing a Trailer”in the Index.
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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

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

Emissions Inspection and Maintenance
Programs
Some state/provincial and local governments have or
may begin programs to inspect the emission control
equipment on your vehicle. Failure to pass this
inspection could prevent you from getting a vehicle
registration.
Here are some things you need to know to help your
vehicle pass an inspection:
Your vehicle will not pass this inspection if the SERVICE
ENGINE SOON or CHECK ENGINE light is on or not
working properly.
Your vehicle will not pass this inspection if the OBD
(on-board diagnostic) system determines that critical
emission control systems have not been completely
diagnosed by the system. The vehicle would be
considered not ready for inspection. This can happen if
you have recently replaced your battery or if your battery
has run down. The diagnostic system is designed to
evaluate critical emission control systems during normal
driving. This may take several days of routine driving.
If you have done this and your vehicle still does not pass
the inspection for lack of OBD system readiness, your
GM dealer can prepare the vehicle for inspection.
Oil Pressure Gage
The oil pressure gage shows the engine oil pressure in
psi (pounds per square inch) when the engine is
running. Canadian vehicles indicate pressure in kPa
(kilopascals).United States
Canada
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2003 - Sonoma OM

{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’t 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
doesn’t collect there.
Open a window just a little on the side of the
vehicle that’s 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.
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2003 - Sonoma OM

When towing your vehicle, turn the ignition to OFF.
To prevent your battery from draining while towing,
remove the RDO BATT and CLSTR fuses from
the instrument panel fuse block. Be sure to replace the
fuse when you reach your destination. SeeFuses
and Circuit Breakers on page 5-89. Be sure to use the
proper towing equipment designed for recreational
vehicle towing. Follow the instructions for the towing
equipment.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P) for
an automatic transmission, or if your vehicle is
in gear, for a manual transmission. You or
others could be injured. Make sure the parking
brake isfirmly set before you shift the transfer
case to NEUTRAL.
If your vehicle has four-wheel-drive it cannot be dinghy
towed. A four-wheel-drive vehicle must be towed by
atbed.
Dolly Towing
Notice:Towing your vehicle with all four wheels on
the ground will damage drivetrain components.
Your two-wheel-drive vehicle should not be towed with
two wheels on the ground. Your transmission has no
provision for internal lubrication while being towed.
To properly tow your vehicle, it should be placed on a
platform trailer with all four wheels off the ground. Towing
with all four wheels on the ground should be avoided.Two-Wheel-Drive Vehicles Only
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2003 - Sonoma OM

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.......................................................5-5
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-6
Filling a Portable Fuel Container.......................5-8
Checking Things Under
the Hood......................................................5-8
Hood Release................................................5-9
Engine Compartment Overview.......................5-10
Engine Oil...................................................5-13
Engine Air Cleaner/Filter................................5-18
Automatic Transmission Fluid
.........................5-20
Manual Transmission Fluid
.............................5-23
Hydraulic Clutch
...........................................5-24Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-27
Engine Overheating.......................................5-28
Cooling System............................................5-30
Engine Fan Noise.........................................5-36
Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-47
Four-Wheel Drive............................................5-48
Front Axle......................................................5-49
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps..................................................5-50
One-Piece Front Turn Signal Lamps................5-52
Two-Piece Front Turn Signal Lamps................5-53
Center High-Mounted Stoplamp (CHMSL).........5-54
Taillamps.....................................................5-55
Replacement Bulbs.......................................5-55
Section 5 Service and Appearance Care
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2003 - Sonoma OM

A. Battery
B. Coolant Recovery Tank
C. Automatic Transmission Dipstick (If Equipped)
D. Engine Oil Fill Cap and Dipstick
E. Power Steering ReservoirF. Brake Master Cylinder
G. Engine Air Cleaner/Filter
H. Engine Compartment Fuse Block
I. Windshield Washer Fluid Reservoir
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2003 - Sonoma OM