2004 GMC SONOMA trailer

22,500 Miles (37 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
30,000 Miles (50 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)❑Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
- In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
- In hilly or mountainous terrain.
- When doing frequent trailer towing.
- Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every 50,000 miles
(83 000 km).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
❑Replace fuel filter.An Emission Control Service. (See
footnote †.)
❑Replace engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
6-19

37,500 Miles (62 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
45,000 Miles (75 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Inspect engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An
Emission Control Service. (See footnote †.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)❑Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
- In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
- In hilly or mountainous terrain.
- When doing frequent trailer towing.
- Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every 50,000 miles
(83 000 km).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
50,000 Miles (83 000 km)
❑If you have not used your vehicle under severe
conditions listed previously and, therefore, have
not changed your automatic transmission fluid,
change both the fluid and filter.
6-20

52,500 Miles (87 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
60,000 Miles (100 000 km)
❑Change engine oil and filter (or every 12 months,
whicheve occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)❑Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
- In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
- In hilly or mountainous terrain.
- When doing frequent trailer towing.
- Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every 50,000 miles
(83 000 km).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
❑Replace fuel filter.An Emission Control Service. (See
footnote †.)
❑Replace engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
6-21

67,500 Miles (112 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
75,000 Miles (125 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Inspect engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An
Emission Control Service. (See footnote †.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)❑Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
- In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
- In hilly or mountainous terrain.
- When doing frequent trailer towing.
- Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change the uid and lter every 50,000 miles
(83 000 km).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
82,500 Miles (137 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
6-22

90,000 Miles (150 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
- In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C) or
higher.
- In hilly or mountainous terrain.
- When doing frequent trailer towing.
- Uses such as found in taxi, police or delivery
service.If you do not use your vehicle under any of these
conditions, change the uid and lter every 50,000 miles
(83 000 km).
❑Replace fuel filter.An Emission Control Service. (See
footnote †.)
❑Replace engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
6-23

Driving (cont.)
Hill and Mountain Roads..............................4-36
In Rain and on Wet Roads...........................4-29
Winter........................................................4-38
Driving Across an Incline..................................4-22
Driving Downhill..............................................4-21
Driving in Mud, Sand, Snow or Ice....................4-25
Driving in Water..............................................4-26
Driving On Grades..........................................4-62
Driving on Off-Road Hills.................................4-18
Driving on Snow or Ice....................................4-39
Driving Through Deep Standing Water...............4-31
Driving Through Flowing Water.........................4-31
Driving Uphill..................................................4-19
Driving with a Trailer.......................................4-60
E
Electrical System
Add-On Equipment......................................5-94
Fuses and Circuit Breakers...........................5-95
Headlamps.................................................5-95
Power Windows and Other Power Options......5-95
Windshield Wiper Fuses...............................5-95
Emissions Inspection and
Maintenance Programs.................................3-31Engine
Air Cleaner/Filter.........................................5-18
Battery.......................................................5-40
Check and Service Engine Soon Light............3-29
Coolant......................................................5-23
Coolant Heater............................................2-19
Coolant Temperature Gage...........................3-28
Cooling System Inspection............................6-30
Drive Belt Routing.......................................6-35
Engine Compartment Overview......................5-12
Exhaust.....................................................2-29
Fan Noise..................................................5-35
Oil .............................................................5-13
Overheating................................................5-26
Starting......................................................2-18
Engine Compartment Fuse Block......................5-98
Engine Coolant Level Check.............................6-25
Engine Oil Additives........................................5-16
Engine Oil Level Check...................................6-25
Engine Speed Control.....................................2-19
Entry Lighting.................................................3-15
Environmental Concerns..................................4-15
Event Data Records (EDR)................................ 7-9
Exit Lighting...................................................3-15
Express Down Window....................................2-13
Extender, Safety Belt.......................................1-26
Exterior Lamps...............................................3-11
5

Gasoline
Octane........................................................ 5-4
Specifications............................................... 5-5
Getting Familiar with Off-Road Driving................4-16
Glove Box.....................................................2-33
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-6
Headlamp High/Low-Beam Changer.................... 3-7
Headlamps....................................................5-49
Bulb Replacement.......................................5-48
Electrical System.........................................5-95
Halogen Bulbs............................................5-48
One-Piece Front Turn Signal Lamps...............5-51
Two-Piece Front Turn Signal Lamps...............5-51
Heated Seats................................................... 1-4
Highway Hypnosis...........................................4-35
Hill and Mountain Roads..................................4-36
Hitches..........................................................4-59
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn............................................................... 3-5
How to Add Automatic
Transmission Fluid.......................................5-22How to Add Coolant to the Coolant
Recovery Tank............................................5-30
How to Add Coolant to the Radiator..................5-32
How to Check................................................5-67
How to Check Lubricant..........................5-46, 5-47
How to Check Power Steering Fluid..................5-36
How to Check the Automatic
Transmission Fluid.......................................5-20
How to Inspect the Engine Air Cleaner/Filter.......5-18
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-13
Hydroplaning..................................................4-31
I
If No Steam Is Coming From Your Engine..........5-27
If Steam Is Coming From Your Engine...............5-26
If the Light Is Flashing.....................................3-30
If the Light Is On Steady.................................3-30
If You Are Caught in a Blizzard.........................4-40
If You Are Stuck in Sand, Mud, Ice or Snow.......4-42
If You Do Decide To Pull A Trailer.....................4-56
Ignition Positions.............................................2-17
Ignition Transmission Lock Check......................6-28
Infants and Young Children, Restraints...............1-29
Inflation - Tire Pressure...................................5-67
Inspection
Brake System.............................................6-31
Engine Cooling System................................6-30
7

Locking Rear Axle............................................ 4-8
Lockout Protection..........................................2-10
Locks
Door........................................................... 2-7
Leaving Your Vehicle....................................2-10
Lockout Protection.......................................2-10
Power Door.................................................. 2-8
Programmable Automatic Door Locks............... 2-8
Rear Door Security Locks.............................2-10
Long Trip/Highway Definition.............................. 6-6
Long Trip/Highway Intervals............................... 6-6
Long Trip/Highway Scheduled Maintenance........6-17
Loss of Control...............................................4-13
Low Fuel Warning Light...................................3-35
Luggage Carrier..............................................2-40
Lumbar
Power Controls............................................. 1-4
M
Maintenance Schedule
At Each Fuel Fill.........................................6-25
At Least Four Times a Year..........................6-27
At Least Once a Month................................6-25
At Least Once a Year..................................6-27
At Least Twice a Year..................................6-26
Brake System Inspection..............................6-31
Engine Cooling System Inspection.................6-30
Exhaust System Inspection...........................6-30Maintenance Schedule (cont.)
Fuel System Inspection................................6-30
How This Section is Organized....................... 6-3
Introduction.................................................. 6-2
Long Trip/Highway Scheduled Maintenance.....6-17
Maintenance Requirements............................. 6-2
Normal Maintenance Replacement Parts.........6-34
Part A - Scheduled Maintenance Services......... 6-4
Part B - Owner Checks and Services.............6-25
Part C - Periodic Maintenance Inspections......6-30
Part D - Recommended Fluids and
Lubricants...............................................6-32
Part E - Maintenance Record........................6-36
Selecting the Right Schedule.......................... 6-5
Short Trip/City Scheduled Maintenance............. 6-6
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection..........................6-30
Throttle System Inspection............................6-31
Transfer Case and Front Axle (Four-Wheel
Drive) Inspection......................................6-31
Using Your................................................... 6-4
Your Vehicle and the Environment................... 6-2
Maintenance When Trailer Towing.....................4-63
Making Turns.................................................4-61
Malfunction Indicator Light................................3-29
Manual Seats................................................... 1-2
Manual Windows............................................2-12
Manually Closing the Sunroof...........................2-43
Matching Transmitter(s) to Your Vehicle............... 2-5
9