2003 GMC SONOMA automatic transmission

Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-82.
Spare Tire Check
At least twice a year, after the monthly ination check of
the spare tire determines that the spare is inated to
the correct tire ination pressure, make sure that
the spare tire is stored securely. Push, pull, and then try
to rotate or turn the tire. If it moves, use the wheel
wrench to tighten the cable. SeeChanging a Flat Tire
on page 5-68.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. SeePart D: Recommended Fluids and
Lubricants on page 6-33.
Manual Transmission Check
Check the transmissionuid level; add if needed.
SeeManual Transmission Fluid on page 5-23. Check
for leaks. Auid leak is the only reason foruid
loss. Have the system inspected and repaired if needed.
Automatic Transmission Check
Check the transmissionuid level; add if needed.
SeeAutomatic Transmission Fluid on page 5-20.Auid
loss may indicate a problem. Check the system and
repair if needed.
Hydraulic Clutch System Check
Check theuid level in the clutch reservoir. See
Hydraulic Clutch on page 5-24.
Auid loss in this system could indicate a problem.
Have the system inspected and repaired at once.
At Least Four Times a Year
Tailgate Lubrication Service
Lubricate tailgate latch bolt, handle assembly pivot
points, and hinges with lubricant recommended
in Part D.
6-27
2003 - Sonoma OM

At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specied in Part D.
Body Lubrication Service
Lubricate all body door and fuel door hinges, latches
and locks, including the glove box and console
doors, the body hood, secondary latch, pivots, spring
anchor, release pawl and any moving seat hardware.
Lubricate the hood safety lever pivot and prop rod pivot.
Part D tells you what to use. More frequent lubrication
may be required when exposed to a corrosive
environment.
Starter Switch Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-32if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push the clutch down halfway and
try to start the engine. The starter should work only
when the clutch is pushed down all the way to the
oor. If the starter works when the clutch isn’t pushed
all the way down, your vehicle needs service.
6-28
2003 - Sonoma OM

Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-32if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don’t start the engine. Without applying
the regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), your vehicle needs service.
Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
With an automatic transmission, the key should turn
to LOCK only when the shift lever is in PARK (P).
With a manual transmission, the key should turn to
LOCK only when you press the key release button.
On all vehicles, the key should come out only in LOCK.
6-29
2003 - Sonoma OM

Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
To check the parking brake’s holding ability: With
the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
To check the PARK (P) mechanism’s holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Underbody Flushing Service
At least every spring, use plain water toush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-30
2003 - Sonoma OM

Part D: Recommended Fluids and
Lubricants
Fluids and lubricants identied below by name, part
number or specication may be obtained from your
dealer.
Usage Fluid/Lubricant
Engine OilEngine oil with the American
Petroleum Institute Certied for
Gasoline Engines starburst symbol
of the proper viscosity. To determine
the preferred viscosity for your
vehicle’s engine, seeEngine Oil on
page 5-13.
Engine Coolant50/50 mixture of clean, drinkable
water and use only DEX-COOL
®
Coolant. SeeEngine Coolant on
page 5-25.
Hydraulic Brake
SystemDelco Supreme 11
®Brake Fluid or
equivalent DOT-3 brakeuid.
Windshield
Washer SolventGM Optilkeen
®Washer Solvent or
equivalent.
Hydraulic
Clutch SystemHydraulic Clutch Fluid (GM Part No.
U.S. 12345347, in Canada
10953517, or equivalent DOT-3
brakeuid).
Usage Fluid/Lubricant
Power Steering
SystemGM Power Steering Fluid (GM Part
No. U.S. 1052884, in Canada
993294, or equivalent).
Manual
Transmission
with V6 EngineSynchromesh Transmission Fluid
(GM Part No. U.S. 12345349, in
Canada 10953465, or equivalent).
Manual
Transmission
with L4 EngineFriction Modied Synchromesh
Transmission Fluid (GM Part No.
U.S. 12377916, in Canada
10953509).
Automatic
TransmissionDEXRON
®-III Automatic
Transmission Fluid.
Key Lock
CylindersMulti-Purpose Lubricant, Superlube
®
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Chassis
LubricationChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Front Wheel
BearingsWheel bearing lubricant meeting
requirements of NLGI #2, Category
GC or GC-LB (GM Part No. U.S.
1051344, in Canada 993037, or
equivalent).
Front and Rear
Axle (Standard
Differential)SAE 80W-90 Axle Lubricant (GM
Part No. U.S. 1052271, in Canada
10950849, or equivalent).
6-33
2003 - Sonoma OM

Usage Fluid/Lubricant
Rear Axle
(Locking
Differential)Axle Lubricant; use only GM Part
No. U.S. 1052271, in Canada
10950849.Do not add friction
modier.
Transfer CaseDEXRON
®-III Automatic
Transmission Fluid.
Transfer Case
Shift LeverChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Rear Driveline
Center Spline
and Universal
JointsChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Constant
Velocity
Universal JointChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Clutch Pushrod
to Clutch Fork
JointChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Usage Fluid/Lubricant
Hood Latch
Assembly,
Secondary
Latch, Pivots,
Spring
Anchor and
Release PawlLubriplate
®Lubricant Aerosol (GM
Part No. U.S. 12346293, in Canada
992723, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Hood and Door
Hinges, Fuel
Filler Door and
Folding SeatsMulti-Purpose Lubricant, Superlube
®
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Tailgate Handle
Pivot Points,
Hinges, Latch
Bolt and
LinkageMulti-Purpose Lubricant, Superlube
®
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Weatherstrip
ConditioningDielectric Silicone Grease (GM Part
No. U.S. 12345579, in Canada
10953014, or equivalent).
Weatherstrip
SqueaksSynthetic Grease with Teon,
Superlube
®(GM Part No. U.S.
12371287, in Canada 10953437,
or equivalent).
6-34
2003 - Sonoma OM

Audio System(s) (cont.)
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 Feature................................3-67
Understanding Radio Reception.....................3-67
Automatic Headlamp System............................3-11
Automatic Transmission...................................2-22
Fluid..........................................................5-20
Operation...................................................2-25
Automatic Transmission Check..........................6-27
Automatic Transmission Shift Lock Control
System Check.............................................6-29
B
Backing Up....................................................4-58
Battery..........................................................5-42
Battery Replacement......................................... 2-6
Battery Rundown Protection.............................3-15
Bed Rails......................................................2-52
Before Leaving on a Long Trip.........................4-33
Before You Go Off-Roading..............................4-13
Body Lubrication Service..................................6-28
Brake
Parking......................................................2-32
System Inspection.......................................6-32Brake (cont.)
System Warning Light..................................3-27
Brake Adjustment............................................5-41
Brake Fluid....................................................5-39
Brake Pedal Travel.........................................5-41
Brake Wear...................................................5-41
Brakes..........................................................5-39
Braking........................................................... 4-5
Braking in Emergencies..................................... 4-7
Break-In, New Vehicle.....................................2-20
Bulb Replacement...........................................5-50
Center High-Mounted Stoplamp (CHMSL)........5-54
Halogen Bulbs............................................5-50
Headlamps.................................................5-50
One-Piece Front Turn Signal Lamps...............5-52
Replacement Bulbs......................................5-55
Taillamps....................................................5-55
Two-Piece Front Turn Signal Lamps...............5-53
Buying New Tires...........................................5-62
C
California Fuel.................................................. 5-5
Canada........................................................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-6
Capacities and Specifications............................5-94
Carbon Monoxide...................4-36, 4-51, 2-12, 2-37
2
2003 - Sonoma OM

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