1999 GMC SONOMA transmission

2-19
CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
See ªShifting Into PARK (P)º in the Index. If
you're pulling a trailer, see ªTowing a Trailerº in
the Index.
Ensure the shift lever is fully in PARK (P) before
starting the engine. Your vehicle has a automatic
transmission shift lock control system. You have to fully
apply your regular brakes before you can shift from
PARK (P) when the ignition key is in RUN. If you
cannot shift out of PARK (P), ease pressure on the shift
lever
-- push the shift lever all the way into PARK (P) as
you maintain brake application. Then move the shift
lever into the gear you wish. See ªShifting Out of
PARK (P)º in the Index.
REVERSE (R): Use this gear to back up.
NOTICE:
Shifting to REVERSE (R) while your
vehicle is moving forward could damage your
transmission. Shift to REVERSE (R) only after
your vehicle is stopped.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission, see
ªStuck In Sand, Mud, Ice or Snowº in the Index.

2-20
NEUTRAL (N): In this position, your engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only.
CAUTION:
Shifting out of PARK (P) or NEUTRAL (N) while
your engine is ªracingº (running at high speed) is
dangerous. Unless your foot is firmly on the
brake pedal, your vehicle could move very
rapidly. You could lose control and hit people or
objects. Don't shift out of PARK (P) or
NEUTRAL (N) while your engine is racing.
NOTICE:
Damage to your transmission caused by shifting
out of PARK (P) or NEUTRAL (N) with the
engine racing isn't covered by your warranty.
DRIVE (D): This position is for normal driving.
If you need more power for passing, and you're:

Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.

Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more power.
DRIVE (D) should not be used when towing a trailer,
carrying a heavy load, driving on steep hills, or for
off
-road driving. Select THIRD (3) when operating the
vehicle under any of these conditions.
THIRD (3): This position is also used for normal
driving, however it offers more power and lower fuel
economy than DRIVE (D). You should use THIRD (3)
when towing a trailer, carrying a heavy load, driving on
steep hills or winding roads or for off
-road driving.
SECOND (2): This position gives you more power but
lower fuel economy than THIRD (3). You can use
SECOND (2) on hills. It can help control your speed as
you go down steep mountain roads, but then you would
also want to use your brakes off and on. You can also
use SECOND (2) for starting your vehicle from a stop
on slippery road surfaces.

2-21
FIRST (1): This position gives you even more power
but lower fuel economy than SECOND (2). You can use
it on very steep hills, or in deep snow or mud. If the
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into
FIRST (1) until the vehicle is going slowly enough.
NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position
on a hill.
Manual Transmission Operation
5-Speed
This is your shift pattern.
Here's how to operate your transmission:
FIRST (1): Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
You can shift into FIRST (1) when you're going less
than 20 mph (30 km/h). If you've come to a complete
stop and it's hard to shift into FIRST (1), put the shift
lever in NEUTRAL and let up on the clutch. Press the
clutch pedal back down. Then shift into FIRST (1).

2-22
SECOND (2): Press the clutch pedal as you let up
on the accelerator pedal and shift into SECOND (2).
Then, slowly let up on the clutch pedal as you press the
accelerator pedal.
THIRD, FOURTH AND FIFTH (3, 4 and 5): Shift
into THIRD (3), FOURTH (4) and FIFTH (5) the same
way you do for SECOND (2). Slowly let up on the
clutch pedal as you press the accelerator pedal.
To stop, let up on the accelerator pedal and press the brake
pedal. Just before the vehicle stops, press the clutch pedal
and the brake pedal, and shift to NEUTRAL.
NEUTRAL: Use this position when you start or idle
your engine.REVERSE (R): To back up, press the clutch pedal.
After the vehicle stops, shift into REVERSE (R).
For vehicles equipped with the VORTEC 4300 V6
engine, you must wait six seconds before shifting into
REVERSE (R). Slowly let up on the clutch pedal as you
press the accelerator pedal.
NOTICE:
Shift to REVERSE (R) only after your vehicle is
stopped. Shifting to REVERSE (R) while your
vehicle is moving could damage your transmission.
Use REVERSE (R), along with the parking brake, for
parking your vehicle.

2-23 Shift Light
If you have a manual
transmission, you have a
SHIFT light.
This light will show you when to shift to the next higher
gear for best fuel economy.
When this light comes on, you can shift to the next
higher gear if weather, road and traffic conditions let
you. For the best fuel economy, accelerate slowly and
shift when the light comes on.
While you accelerate, it is normal for the light to go on
and off if you quickly change the position of the
accelerator. Ignore the SHIFT light when you downshift.
CAUTION:
If you skip a gear when you downshift, you could
lose control of your vehicle. You could injure
yourself or others. Don't shift down more than
one gear at a time when you downshift.
Four-Wheel Drive (If Equipped)
If your vehicle has four-wheel drive, you can send your
engine's driving power to all four wheels for extra
traction. To get the most satisfaction out of four
-wheel
drive, you must be familiar with its operation. Read the
part that follows before using four
-wheel drive. You
should use two
-wheel drive (2HI) for most normal
driving conditions.
NOTICE:
Driving in the 4HI or 4LO positions for a long
time on dry or wet pavement could shorten the
life of your vehicle's drivetrain.

2-25
Shifting from 2HI or 4HI to 4LO
To shift from 2HI or 4HI to 4LO, the vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N) in vehicles equipped
with an automatic transmission or the clutch pedal
engaged in vehicles equipped with a manual
transmission. The preferred method for shifting into
4LO is to have your vehicle moving 1 to 2 mph (1.6 to
3.2 km/h). Press and release the 4LO switch. You must
wait for the 4LO indicator light to stop flashing and
remain illuminated before shifting your transmission
into gear or releasing the clutch pedal.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving slower than 3 mph (4.8 km/h) and
the transmission is in NEUTRAL (N) or the clutch
pedal engaged.On automatic transmission equipped vehicles, if your
transfer case does not shift into 4LO, your transmission
indicator switch may require adjustment. With your
transmission in NEUTRAL (N), press and release the
4LO switch. While the 4LO indicator light is flashing,
shift your transmission into PARK (P). Wait until the
4LO indicator light remains illuminated before shifting
your transmission into gear. This will get you into 4LO,
but you should take your vehicle in for service to restore
normal operation.
Shifting from 4LO to 4HI or 2HI
To shift from 4LO to 4HI or 2HI, your vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N) or the clutch pedal
engaged. The preferred method for shifting out of 4LO is
to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
Press and release the 4HI switch. You must wait for the
4HI indicator light to stop flashing and remain illuminated
before shifting your transmission into gear or releasing the
clutch pedal.

2-26
If the 4HI switch is pressed when your vehicle is in gear
and/or moving, the 4HI indicator light will flash for
30 seconds but not complete the shift unless the vehicle
is moving slower than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N) or the clutch
pedal engaged.
On automatic transmission equipped vehicles, if your
transfer case does not shift into 4HI, your transmission
indicator switch may require adjustment. With your
transmission in NEUTRAL (N), press and release the
4HI switch. While the 4HI indicator light is flashing,
shift your transmission into PARK (P). Wait until the
4HI indicator light remains illuminated before shifting
your transmission into gear. This will get you into 4HI,
but you should take your vehicle in for service to restore
normal operation.
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking brake
pedal with your left foot. If the ignition is on, the brake
system warning light will come on.
To release the parking brake hold the regular brake
pedal down.
Pull the BRAKE RELEASE lever fully. It is located on
the bottom of the driver's side of the instrument panel.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle.
If you are towing a trailer and you must park on a hill,
see ªTowing a Trailerº in the Index. That section shows
what to do first to keep the trailer from moving.

2-27
Shifting Into PARK (P)
(Automatic Transmission Only)
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle won't move, even
when you're on fairly level ground, use the steps
that follow. Always put the shift lever fully in
PARK (P) with the parking brake firmly set. If
you're pulling a trailer, see ªTowing a Trailerº in
the Index.
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into PARK (P) position
like this:

Pull the lever toward you.