Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-3
Rear Seats
............................................... 1-9
Safety Belts
.............................................1-10
Child Restraints
.......................................1-30
Air Bag System
.......................................1-54
Restraint System Check
............................1-64
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
....................................... 2-8
Windows
.................................................2-14
Theft-Deterrent Systems
............................2-17
Starting and Operating Your Vehicle
...........2-20
Mirrors
....................................................2-39
Storage Areas
.........................................2-41
Sunroof
..................................................2-52
Vehicle Personalization
.............................2-54
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-2
Climate Controls
......................................3-17
Warning Lights, Gages and Indicators
.........3-20
Audio System(s)
.......................................3-36
Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-42Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-4
Checking Things Under the Hood
................. 5-8
Rear Axle
...............................................5-47
Four-Wheel Drive
.....................................5-48
Front Axle
...............................................5-49
Bulb Replacement
....................................5-50
Windshield Wiper Blade Replacement
.........5-56
Tires
......................................................5-58
Appearance Care
.....................................5-79
Vehicle Identification
.................................5-87
Electrical System
......................................5-88
Capacities and Specifications
.....................5-94
Normal Maintenance Replacement Parts
......5-96
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance Information
.................. 7-2
Reporting Safety Defects
............................ 7-8
Index................................................................ 1
2003 GMC Sonoma Owner ManualM
2003 - Sonoma Owner Manual
Turn Signal/Multifunction Lever
The lever on the left side of the steering column
includes the following:
Turn and Lane-Change Signals
Headlamp High/Low-Beam Changer
Flash-to-Pass Feature
Windshield Wipers
Windshield Washer
Cruise Control (If Equipped)
Turn and Lane-Change Signals
The turn signal has two upward (for right) and two
downward (for left) positions. These positions allow you
to signal a turn or a lane change.
To signal a turn, move the lever all the way up or
down. When the turn is nished, the lever will return
automatically.
An arrow on the
instrument panel cluster
will ash in the direction of
the turn or lane change.
To signal a lane change, just raise or lower the lever
until the arrow starts to ash. Hold it there until you
complete your lane change. The lever will return by itself
when you release it.
As you signal a turn or a lane change, if the arrows
don’t ash but just stay on, a signal bulb may be burned
out and other drivers won’t see your turn signal.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows don’t go on at all when you signal
a turn, check the fuse (seeFuses and Circuit Breakers
on page 5-89) and for burned-out bulbs.
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2003 - Sonoma OM
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns
than normal. Do this so your trailer won’t strike
soft shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have extra
wiring and a heavy-duty turn signal asher.
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
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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
5-1
2003 - Sonoma OM
Bulb Replacement
SeeReplacement Bulbs on page 5-55for the proper
types of bulbs to use. For any bulb changing procedure
not listed in this section, contact your GM dealer’s
service department.
Halogen Bulbs
{CAUTION:
Halogen bulbs have pressurized gas inside
and can burst if you drop or scratch the bulb.
You or others could be injured. Be sure to
read and follow the instructions on the bulb
package.
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.
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2003 - Sonoma OM
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.
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.
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2003 - Sonoma OM
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.
One-Piece Front Turn Signal Lamps
1. Remove the headlamp assembly as shown in
″One-Piece Composite Headlamp System″
underHeadlamps on page 5-50.
2. Twist the bulb socket
counterclockwise
to remove it from the
headlamp assembly.
3. Pull the bulb straight out to remove it from the
socket.
4. Push the new bulb into the socket until it snaps
into place.
5. Put the bulb socket into the lamp assembly and
twist it clockwise until it is tight.
6. Put the headlamp assembly back into the vehicle.
7. Install the two retaining clips.
8. Close the hood.
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2003 - Sonoma OM
Two-Piece Front Turn Signal Lamps
1. Remove the headlamp assembly as shown in
″Two-Piece Composite Headlamp System″
underHeadlamps on page 5-50.
2. Locate the locking
tabs on the assembly.
Squeeze the tabs
together and push that
end of the assembly
out while holding
the tabs. The assembly
will swing out.3. Unplug the electrical connector.
4. Turn the harness bulb socket counterclockwise to
remove it. Pull the bulb straight out to remove it
from the socket.
5. Push the new bulb into the socket until it snaps
into place.
6. Put the socket into the lamp assembly and turn it
clockwise until it is tight.
7. To reinstall the assembly, snap the outboard end of
the lamp assembly back into the vehicle. Then
swing the assembly in and snap it into place.
8. Install the two retaining clips.
9. Close the hood.
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2003 - Sonoma OM