2003 GMC SONOMA hood release

Never go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal pressed
down in a manual shift. This is called“free-wheeling”.
Your brakes will have to do all the work and could
overheat and fade.
Q:Am I likely to stall when going downhill?
A:It’s much more likely to happen going uphill. But if
it happens going downhill, here’s what to do.
Stop your vehicle by applying the regular brakes.
Apply the parking brake.
Shift to PARK (P) (or to neutral with the manual
transmission) and, while still braking, restart the
engine.
Shift back to a low gear, release the parking brake,
and drive straight down.
If the engine won’t start, get out and get help.
Driving Across an Incline
Sooner or later, an off-road trail will probably go
across the incline of a hill. If this happens, you have to
decide whether to try to drive across the incline.
Here are some things to consider:
A hill that can be driven straight up or down may be
too steep to drive across. When you go straight up
or down a hill, the length of the wheel base (the
distance from the front wheels to the rear wheels)
reduces the likelihood the vehicle will tumble
end over end. But when you drive across an incline,
the much more narrow track width (the distance
between the left and right wheels) may not prevent
the vehicle from tilting and rolling over. Also,
driving across an incline puts more weight on the
downhill wheels. This could cause a downhill
slide or a rollover.
Surface conditions can be a problem when you
drive across a hill. Loose gravel, muddy spots,
or even wet grass can cause your tires to slip
sideways, downhill. If the vehicle slips sideways,
it can hit something that will trip it (a rock, a rut, etc.)
and roll over.
4-22
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

Hood Release
To open the hood, do the following:
1. Pull the handle
located inside the
vehicle on the lower
left side of the
instrument panel.
2. Lift the hood.3. Release the hood prop from its retainer and put the
hood prop into the slot in the hood.
Before closing the hood, be sure all thefiller caps are
on properly. Then lift the hood to relieve pressure on the
hood prop.
Remove the hood prop from the slot in the hood and
return the prop to its retainer.
Then, pull the hood downfirmly to close. It will latch
when dropped from about 10 to 12 inches (25 to 30 cm)
without pressing on the hood.
5-9
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

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

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