1999 GMC SONOMA transmission oil

2-18 To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord is located on the driver's side of the engine
compartment, behind the underhood fuse block.
3. Plug it into a normal, grounded 110
-volt AC outlet.
CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the wrong
kind of extension cord could overheat and cause
a fire. You could be seriously injured. Plug the
cord into a properly grounded three
-prong
11 0
-volt AC outlet. If the cord won't reach, use a
heavy
-duty three-prong extension cord rated for
at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away from
moving engine parts. If you don't, it could
be damaged.How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact
your dealer in the area where you'll be parking your
vehicle. The dealer can give you the best advice for that
particular area.
Automatic Transmission Operation
Your automatic transmission has a shift lever on the
steering column.
There are several different positions for your shift lever.
It features an electronic shift position indicator within
the instrument cluster. This display must be powered
anytime the shift lever is capable of being moved out of
PARK (P). This means that if your key is in OFF, but
not locked, there will be a small current drain on your
battery which could discharge your battery over a period
of time. If you need to leave your key in the ignition in
OFF for an extended period, it is recommended that you
disconnect the battery cable from the battery to prevent
discharging your battery.
PARK (P): This locks your rear wheels. It's the best
position to use when you start your engine because your
vehicle can't move easily.

4-53
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine off.
If you do get the overheat warning, see ªEngine
Overheatingº in the Index.
Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet, or into gear for a manual
transmission. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P), or
REVERSE (R) for a manual transmission.
5. Release the regular brakes.

4-54 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

Start your engine;

Shift into a gear; and

Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in
trailer operation are automatic transmission fluid
(don't overfill), engine oil, axle lubricant, belt, cooling
system and brake system. Each of these is covered in
this manual, and the Index will help you find them
quickly. If you're trailering, it's a good idea to review
these sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel (Gasoline)
6
-5 Fuel E-85 (85% Ethanol)
6
-6 Fuels in Foreign Countries
6
-7 Filling Your Tank
6
-9 Filling a Portable Fuel Container
6
-10 Checking Things Under the Hood
6
-13 Engine Oil
6
-18 Engine Air Cleaner/Filter
6
-19 Automatic Transmission Fluid
6
-23 Manual Transmission Fluid
6
-24 Hydraulic Clutch
6
-24 Rear Axle
6
-25 Four-Wheel Drive
6
-27 Engine Coolant
6
-30 Radiator Pressure Cap
6
-30 Power Steering Fluid
6
-31 Windshield Washer Fluid6
-32 Brakes
6
-36 Battery
6
-37 Bulb Replacement
6
-43 Windshield Wiper Blade Replacement
6
-45 Tires
6
-53 Appearance Care
6
-54 Cleaning the Inside of Your Vehicle
6
-56 Care of Safety Belts
6
-57 Cleaning the Outside of Your Vehicle
6
-60 GM Vehicle Care/Appearance Materials Chart
6
-61 Vehicle Identification Number (VIN)
6
-61 Service Parts Identification Label
6
-62 Electrical System
6
-67 Replacement Bulbs
6
-67 Capacities and Specifications
6
-69 Normal Maintenance Replacement Parts

6-11
When you lift the hood, you'll see these items on the 2200 L4 engine:
A. Battery
B. Coolant Recovery Tank
C. Automatic Transmission Dipstick
D. Engine Oil Fill Cap and DipstickE. Power Steering Reservoir
F. Brake Master Cylinder
G. Engine Air Cleaner/Filter
H. Engine Compartment Fuse Block
I. Windshield Washer Fluid Reservoir

6-12
When you lift the hood, you'll see these items on the ªVORTECº 4300 V6 engine:
A. Battery
B. Coolant Recovery Tank
C. Engine Oil Dipstick
D. Engine Oil Fill
E. Automatic Transmission DipstickF. Power Steering Reservoir
G. Brake Master Cylinder
H. Engine Air Cleaner/Filter
I. Engine Compartment Fuse Block
J. Windshield Washer Fluid Reservoir

6-19
CAUTION:
Operating the engine with the air cleaner/filter
off can cause you or others to be burned. The air
cleaner not only cleans the air, it stops flame if
the engine backfires. If it isn't there, and the
engine backfires, you could be burned. Don't
drive with it off, and be careful working on the
engine with the air cleaner/filter off.
NOTICE:
If the air cleaner/filter is off, a backfire can cause
a damaging engine fire. And, dirt can easily get
into your engine, which will damage it.
Always have the air cleaner/filter in place
when you're driving.
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter 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 90F (32C) 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 fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.

6-23
Manual Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
changed. However, the fluid 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 fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire. Be
sure to get an accurate reading if you check your
transmission fluid.
Check the fluid 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 your fingers on the transmission case.
Then, follow these steps:
1. Remove the filler plug.
2. Check that the lubricant level is up to the bottom of
the filler plug hole.
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.