Page 281 of 424

Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, thefluid in your manual transmission
doesn’t require changing.
How to Check
Because this operation can be a little difficult, you may
choose to have this done at your GM dealership
service department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading.
Notice:Too much or too little uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission uid.
Check thefluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest yourfingers on the
transmission case.Then, follow these steps:
1. Remove thefiller plug.
2. Check that the lubricant level is up to the bottom of
thefiller plug hole.
3. If thefluid level is good, install the plug and be sure
it is fully seated. If thefluid level is low, add more
fluid as described in the next steps.
5-23
2003 - Sonoma OM
Page 301 of 424

Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. Be sure to follow the steps below to do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you don’t follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that wouldn’t be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won’t work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12–volt
battery with a negative ground system.Notice:If the other system isn’t a 12-volt system
with a negative ground, both vehicles can be
damaged.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brakefirmly on both vehicles involved
in the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure
the transfer case is not in NEUTRAL (N).
Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all lamps that aren’t needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
5-43
2003 - Sonoma OM
Page 326 of 424

Changing a Flat Tire
If a tire goesflat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warningflashers.
{CAUTION:
Changing a tire can cause an injury. The
vehicle can slip off the jack and roll over you
or other people. You and they could be badly
injured. Find a level place to change your tire.
To help prevent the vehicle from moving:
1. Set the parking brake rmly.
2. Put an automatic transmission shift lever in
PARK (P), or shift a manual transmission to
FIRST (1) or REVERSE (R).
3. Turn off the engine.
Put the wheel blocks at the front and rear
of the tire farthest away from the one
being changed. That would be the tire on
the other side of the vehicle, at the
opposite end.The following steps will tell you how to use the jack and
change a tire.
Removing the Spare Tire and Tools
The jacking equipment you’ll need is stored inside the
plastic jack cover which is behind the front seats, either
on the center of the wall (extended cab) or on the
passenger’s side of the wall (regular cab).
The jacking equipment for the crew cab is located behind
the rear seatback on the passenger’s side of the vehicle.
5-68
2003 - Sonoma OM
Page 348 of 424
Fuse Usage
A Not Used
B Not Used
1 Not Used
2 Cigarette Lighter, Data Link
Connector
3 Cruise Control Module and Switch,
Body Control Module, Heated SeatsFuse Usage
4 Gages, Body Control Module,
Instrument Panel Cluster
5 Parking Lamps, Power Window
Switch, Body Control Module,
Ashtray Lamp
6 Steering Wheel Radio Controls
7 Headlamps Switch, Body Control
Module, Headlamp Relay
8 Courtesy Lamps, Battery Run-Down
Protection
9 Heating, Ventilation, Air Cooling
Control Head (Manual)
10 Turn Signal
11 Cluster, Engine Control Module
12 Interior Lights
13 Auxiliary Power
14 Power Locks Motor
15 4WD Switch, Engine Controls
(VCM, PCM, Transmission)
16 Supplemental Inflatable Restraint
17 Front Wiper
18 Steering Wheel Radio Controls
19 Radio, Battery
5-90
2003 - Sonoma OM
Page 353 of 424
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 Speci cations
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
Page 366 of 424