2003 GMC SONOMA automatic transmission fluid

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

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
5-11
2003 - Sonoma OM

When you open the hood on the 4300 V6 engine, you’ll see:
A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Automatic Transmission Dipstick (If Equipped)F. Power Steering Reservoir
G. Brake Master Cylinder Reservoir
H. Engine Air Cleaner/Filter
I. Engine Compartment Fuse Block
J. Windshield Washer Fluid Reservoir
5-12
2003 - Sonoma OM

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmissionfluid
level is when the engine oil is changed.
Change both thefluid andfilter every 15,000 miles
(25 000 km) 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 thefluid andfilter every
50,000 miles (83 000 km).
SeePart A: Scheduled Maintenance Services
on page 6-4.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at the dealership service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too littleuid can damage
your transmission. Too much can mean that some
of theuid could come out and fall on hot engine
part or exhaust system parts, starting are.
Too littleuid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmissionuid.
Wait at least 30 minutes before checking the
transmissionfluid level if you have been driving:
•When outside temperatures are above 90°F (32°C).
•At high speed for quite a while.
•In heavy traffic–especially in hot weather.
•While pulling a trailer.
To get the right reading, thefluid should be at normal
operating temperature, which is 180°Fto200°F
(82°Cto93°C)
5-20
2003 - Sonoma OM

3. Check both sides of the dipstick, and read the lower
level. Thefluid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a hot
check.
4. If thefluid level is in the acceptable range, push the
dipstick back in all the way; thenflip the handle
down to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmissionfluid to use. SeePart D:
Recommended Fluids and Lubricants on page 6-33.
Addfluid only after checking the transmissionfluid while
it is hot. (A cold check is used only as a reference.)
If thefluid level is low, add only enough of the proper
fluid to bring the level up to the HOT area for a hot
check. It doesn’t take muchfluid, generally less
than one pint (0.5 L). Don’t overfill.
Notice:We recommend you use onlyuid labeled
DEXRON
®-III, becauseuid with that label is
made especially for your automatic transmission.
Damage caused byuid other than DEXRON
®-III is
not covered by your new vehicle warranty.
•After addingfluid, recheck thefluid level as
described under“How to Check”earlier.
•When the correctfluid level is obtained, push the
dipstick back in all the way; thenflip the handle
down to lock the dipstick in place.
5-22
2003 - Sonoma OM

ApplicationCapacities
English Metric
Automatic Transmission
Drain and Refill5.0 quarts 4.7 L
Differential Fluid
Rear Axle
Front Axle4.0 pints
2.6 pints1.9 L
1.2 L
Air Conditioning Capacity
Air Conditioning Refrigerant R134a1.8 lbs 0.79 kg
All capacities are approximate. After refill, the levelmustbe checked.
All capacities are approximate. When adding, be sure tofill to the appropriate level or as recommended in
this manual. SeePart E: Maintenance Record on page 6-35
Capacities and Specications
Type VIN Code Transmission Spark Plug Gap Firing Order
2200
L4HAutomatic
Manual0.040 inches
(1.01 mm)1-3-4-2
4300
V6XAutomatic
Manual0.060 inches
(1.52 mm)1-6-5-4-3-2
5-95
2003 - Sonoma OM

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

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