
Flat Tire........................................................5-67
Flat Tire, Changing.........................................5-68
Fluid
Automatic Transmission................................5-20
Manual Transmission....................................5-23
Power Steering...........................................5-37
Windshield Washer......................................5-38
FM ...............................................................3-67
Fog Lamps ....................................................3-13
Following Distance..........................................4-57
Four-Wheel Drive....................................2-29, 5-48
Front Axle......................................................5-49
Front Map Lamps...........................................3-14
Front Storage Area.........................................2-49
Fuel............................................................... 5-4
Additives...................................................... 5-5
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-8
Filling Your Tank........................................... 5-6
Fuels in Foreign Countries.............................. 5-6
Gage .........................................................3-35
Gasoline Octane........................................... 5-4
Gasoline Specifications.................................. 5-5
Low Warning Light.......................................3-35
System Inspection
.......................................6-31
Fuses
Fuses and Circuit Breakers
...........................5-89
Windshield Wiper
.........................................5-88G
Gage
Check Gages Warning Light..........................3-34
Engine Coolant Temperature.........................3-29
Fuel..........................................................3-35
Oil Pressure...............................................3-32
Speedometer..............................................3-23
Tachometer.................................................3-23
Voltmeter Gage...........................................3-26
Garment Hooks..............................................2-50
Gasoline
Octane........................................................ 5-4
Specifications............................................... 5-5
Getting Familiar with Off-Road Driving................4-16
Glass Surfaces...............................................5-81
Glove Box.....................................................2-41
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
H
Hazard Warning Flashers................................... 3-3
Head Restraints............................................... 1-7
Headlamp High/Low-Beam Changer.................... 3-6
Headlamps....................................................5-50
Bulb Replacement.......................................5-50
Electrical System.........................................5-88
6
2003 - Sonoma OM

Headlamps (cont.)
Halogen Bulbs............................................5-50
One-Piece Front Turn Signal Lamps...............5-52
Two-Piece Front Turn Signal Lamps...............5-53
Heated Seats................................................... 1-5
Heating.........................................................3-18
Highway Hypnosis...........................................4-34
Hill and Mountain Roads..................................4-34
Hitches..........................................................4-56
Hood
Checking Things Under.................................. 5-8
Release....................................................... 5-9
Horn ............................................................... 3-4
How to Add Coolant to the Coolant
Recovery Tank............................................5-32
How to Add Coolant to the Radiator..................5-34
How to Add Fluid....................................5-22, 5-24
How to Check................................5-20, 5-23, 5-59
How to Check and Add Fluid
............................5-25
How to Check Lubricant
..........................5-47, 5-49
How to Check Power Steering Fluid
..................5-37
How to Inspect the Engine Air Cleaner/Filter
.......5-19
How to Use This Manual
...................................... ii
How to Wear Safety Belts Properly
...................1-15
Hydraulic Clutch
.............................................5-24
Hydraulic Clutch System Check
........................6-27
Hydroplaning
..................................................4-30I
If No Steam Is Coming From Your Engine..........5-29
If Steam Is Coming From Your Engine...............5-28
If the Light Is Flashing.....................................3-30
If the Light Is On Steady.................................3-31
If You Are Stuck in Sand, Mud, Ice or Snow.......4-40
If You Do Decide To Pull A Trailer.....................4-52
If You’re Caught in a Blizzard...........................4-38
Ignition Positions.............................................2-20
Ignition Transmission Lock Check......................6-29
Infants and Young Children, Restraints...............1-32
Inflation–Tire Pressure...................................5-58
Inspection
Brake System.............................................6-32
Engine Cooling System................................6-31
Exhaust System..........................................6-31
Fuel System...............................................6-31
Part C - Periodic Maintenance.......................6-31
Steering, Suspension and Front Drive
Axle Boot and Seal..................................6-31
Throttle System...........................................6-32
Transfer Case and Front Axle
(Four-Wheel Drive)...................................6-32
Installing a Garage Door Opener.......................2-43
Instrument Panel
Cluster.......................................................3-21
Overview..................................................... 3-2
7
2003 - Sonoma OM

Locks
Door ........................................................... 2-8
Leaving Your Vehicle....................................2-11
Lockout Protection.......................................2-11
Power Door .................................................. 2-9
Programmable Automatic Door Locks............... 2-9
Rear Door Security Locks.............................2-11
Long Trip/Highway Definition.............................. 6-6
Long Trip/Highway Intervals............................... 6-6
Long Trip/Highway Scheduled Maintenance........6-18
Loss of Control...............................................4-12
Low Fuel Warning Light...................................3-35
Luggage Carrier..............................................2-50
Lumbar
Manual Controls............................................ 1-4
Power Controls............................................. 1-5
M
Maintenance, Normal Replacement Parts............5-96
Maintenance Schedule
At Each Fuel Fill.........................................6-26
At Least Four Times a Year..........................6-27
At Least Once a Month................................6-26
At Least Once a Year..................................6-28
At Least Twice a Year..................................6-26Maintenance Schedule (cont.)
Brake System Inspection..............................6-32
Engine Cooling System Inspection.................6-31
Exhaust System Inspection...........................6-31
Fuel System Inspection................................6-31
How This Section is Organized....................... 6-3
Introduction.................................................. 6-2
Long Trip/Highway Scheduled Maintenance.....6-18
Maintenance Requirements............................. 6-2
Part A - Scheduled Maintenance Services......... 6-4
Part B - Owner Checks and Services.............6-26
Part C - Periodic Maintenance Inspections......6-31
PartD-Recommended Fluids and
Lubricants...............................................6-33
PartE-Maintenance Record........................6-35
Selecting the Right Schedule
.......................... 6-5
Short Trip/City Scheduled Maintenance
............. 6-7
Steering, Suspension and Front Drive
Axle Boot and Seal Inspection
...................6-31
Throttle System Inspection
............................6-32
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
....................6-32
Using Your
................................................... 6-4
Your Vehicle and the Environment
................... 6-2
Maintenance When Trailer Towing
.....................4-60
Making Turns
.................................................4-58
9
2003 - Sonoma OM

Parking
Brake........................................................2-32
Over Things That Burn.................................2-36
Parking Brake and Automatic Transmission
Park (P) Mechanism Check...........................6-30
Parking on Hills..............................................4-59
Parking Your Vehicle.......................................2-36
Part A - Scheduled Maintenance Services............ 6-4
Part B - Owner Checks and Services................6-26
Part C - Periodic Maintenance Inspections..........6-31
PartD-Recommended Fluids and Lubricants....6-33
PartE-Maintenance Record...........................6-35
Passing.................................................4-10, 4-58
Passlock
®......................................................2-19
Payload.........................................................4-48
Pickup Conversion to Chassis Cab....................4-50
Plan Ahead When Possible................................ 7-7
Playing a Cassette Tape..................................3-52
Playing a Compact Disc..................3-45, 3-54, 3-62
Playing a Specific Loaded
Compact Disc
.............................................3-63
Playing the Radio
...................3-37, 3-40, 3-47, 3-56
Power
Accessory Outlets
........................................3-15
Door Locks
.................................................. 2-9
Electrical System
.........................................5-88
Lumbar Controls
........................................... 1-5
Seat
............................................................ 1-4Power (cont.)
Steering Fluid.............................................5-37
Windows....................................................2-15
Power Steering................................................ 4-8
Programmable Automatic Door Locks.................. 2-9
Q
Questions and Answers About Safety Belts.........1-15
R
Radiator Pressure Cap....................................5-27
Radio Messages.............................3-39, 3-45, 3-52
Radios..........................................................3-36
AM-FM Radio.............................................3-37
Care of Your Cassette Tape Player................3-68
Care of Your CD Player...............................3-69
Care of Your CDs ........................................3-69
Radio with Cassette and CD.........................3-47
Radio with CD............................................3-40
Radio with Six-Disc CD................................3-56
Setting the Time for Radios with Radio
Data Systems (RDS)................................3-37
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-36
Theft-Deterrent............................................3-67
Understanding Reception..............................3-67
RDS Messages..............................3-43, 3-51, 3-61
11
2003 - Sonoma OM

Stalling on an Incline.......................................4-24
Starter Switch Check.......................................6-28
Starting Your Engine.......................................2-22
Shifting Into................................................2-22
Starting Your VORTEC™2200 L4 Engine............ 6-4
Starting Your VORTEC™4300 V6 Engine..........2-23
Steering.......................................................... 4-8
Steering in Emergencies.................................... 4-9
Steering, Suspension and Front Drive
Axle Boot and Seal Inspection.......................6-31
Steering Tips................................................... 4-8
Storage
Garment Hooks...........................................2-50
Storage Areas
Front Storage Area......................................2-49
Glove Box..................................................2-41
Luggage Carrier..........................................2-50
Overhead Console.......................................2-42
Storing a Flat or Spare Tire and Tools...............5-76
Stuck in Sand, Mud, Ice or Snow......................4-40
Sun Visors.....................................................2-16
Sunglasses Storage Compartment.....................2-46
Sunroof.........................................................2-52
Swing-Out Windows........................................2-16
T
Tachometer....................................................3-23
Tailgate.........................................................2-12Tailgate Lubrication Service..............................6-27
Taillamps.......................................................5-55
Temperature and Compass Display....................2-44
Testing the Alarm............................................2-18
Theft-Deterrent, Radio.....................................3-67
Theft-Deterrent Systems...................................2-17
Content Theft-Deterrent
................................2-17
Passlock
®...................................................2-19
Third Door
.....................................................2-12
Throttle System Inspection
...............................6-32
Tilt Wheel
........................................................ 3-4
Time Delay
....................................................2-39
Tire Inflation Check
.........................................6-26
Tires
.....................................................5-58, 5-84
Buying New Tires
........................................5-62
Chains
.......................................................5-66
Changing a Flat Tire
....................................5-68
Compact Spare Tire
.....................................5-78
If a Tire Goes Flat
.......................................5-67
Inflation–Tire Pressure
...............................5-58
Inspection and Rotation
................................5-60
Uniform Tire Quality Grading
.........................5-63
Wheel Alignment and Tire Balance
.................5-64
Wheel Replacement
.....................................5-65
When It Is Time for New Tires
......................5-61
To Use the Engine Coolant Heater
....................2-24
Top of the Instrument Panel
.............................5-81
Top Strap
......................................................1-41
14
2003 - Sonoma OM

Vinyl.............................................................5-80
Visors...........................................................2-16
Voltmeter Gage..............................................3-26
W
Warning Lights, Gages and Indicators................3-20
Warnings
Hazard Warning Flashers............................... 3-3
Other Warning Devices.................................. 3-4
Safety and Symbols......................................... iii
Vehicle Damage.............................................. iv
Washing Your Vehicle......................................5-82
Weatherstrip Lubrication...................................6-27
Weight of the Trailer........................................4-53
Weight of the Trailer Tongue.............................4-55
What Kind of Engine Oil to Use........................5-14
What to Add ..................................................5-40
What to Do with Used Oil ................................5-17
What to Use ..........................5-26, 5-38, 5-47, 5-49
Wheels
Alignment and Tire Balance..........................5-64
Replacement...............................................5-65
When to Add Engine Oil..................................5-13
When to Change Engine Oil.............................5-16
When to Check......................................5-23, 5-59
When to Check and Change............................5-20
When to Check and Change Lubricant.......5-47, 5-49When to Check and What to Use.....................5-24
When to Check Power Steering Fluid................5-37
When to Inspect the Engine Air Cleaner/Filter.....5-19
When You Are Ready to Leave
After Parking on a Hill..................................4-60
Where to Put the Restraint.......................1-39, 1-40
Why Safety Belts Work....................................1-12
Window Lockout.............................................2-15
Windows.......................................................2-14
Manual......................................................2-15
Power ........................................................2-15
Sliding Rear................................................2-16
Swing-Out Windows.....................................2-16
Windshield and Wiper Blades...........................5-84
Windshield Washer........................................... 3-7
Fluid..........................................................5-38
Windshield Washer Fluid Level Check................6-26
Windshield Wiper
Blade Replacement......................................5-56
Fuses........................................................5-88
Windshield Wipers............................................ 3-7
Winter Driving................................................4-36
Wiper Blade Check.........................................6-27
Wood Panels.................................................5-81
Y
Your Vehicle and the Environment....................... 6-2
16
2003 - Sonoma OM