
Keys...............................................................2-3
Remote Keyless Entry System.........................2-4
Remote Keyless Entry System Operation...........2-5
Doors and Locks.............................................2-8
Door Locks....................................................2-8
Power Door Locks..........................................2-9
Programmable Automatic Door Locks................2-9
Rear Door Security Locks..............................2-11
Lockout Protection........................................2-11
Leaving Your Vehicle....................................2-11
Third Door...................................................2-12
Tailgate.......................................................2-12
Windows........................................................2-14
Manual Windows..........................................2-15
Power Windows............................................2-15
Swing-Out Windows......................................2-16
Sliding Rear Window.....................................2-16
Sun Visors...................................................2-16
Theft-Deterrent Systems..................................2-17
Content Theft-Deterrent.................................2-17
Passlock
®....................................................2-19Starting and Operating Your Vehicle................2-20
New Vehicle Break-In....................................2-20
Ignition Positions..........................................2-20
Starting Your Engine.....................................2-22
Engine Coolant Heater..................................2-24
Automatic Transmission Operation...................2-25
Manual Transmission Operation......................2-28
Four-Wheel Drive..........................................2-29
Parking Brake..............................................2-32
Shifting Into Park (P).....................................2-33
Shifting Out of Park (P).................................2-35
Parking Your Vehicle.....................................2-36
Parking Over Things That Burn.......................2-36
Engine Exhaust............................................2-37
Running Your Engine While You Are Parked. . . .2-38
Mirrors...........................................................2-39
Manual Rearview Mirror.................................2-39
Automatic Dimming Rearview Mirror................2-39
Outside Manual Mirror...................................2-39
Outside Power Mirrors...................................2-40
Outside Convex Mirror...................................2-40
Outside Heated Mirrors..................................2-41
Section 2Features and Controls
2-1
2003 - Sonoma OM

No doors lock/None of the doors unlock:Press the
lock side of the power door lock switch twice. This
turns off the automatic lock feature. This is the factory
setting.
For more information, see your dealer.
If your vehicle has an automatic transmission it will be
programmed to have all the doors lock automatically
when the shift lever is moved out of PARK (P). All the
doors will unlock when the shift lever is moved back into
PARK (P).
On a manual transmission, all doors will lock when the
vehicle speed is greater than 15 mph (24 km/h).
The doors will unlock when the key is removed from the
ignition.
The following instructions detail how to program your
door locks. Choose one of the programming options
before entering the programming mode.To enter the program mode, do the following:
1. Begin with the ignition in OFF. Then pull the turn
signal/multifunction lever all the way toward you
and hold it while you perform the next step.
2. Turn your key to RUN and OFF twice. Then, with
the key in OFF, release the turn signal/multifunction
lever. Once you do this, you will hear the lock
switch lock and unlock.
3. You are now ready to program the automatic door
locks. Select one of the previous four programming
options and follow the instructions. You will have
30 seconds to begin programming. If you exceed
the 30 second limit, the locks will automatically lock
and unlock to indicate you have left the program
mode. If this occurs, repeat the procedure beginning
with Step 1. You can exit the program mode any
time by turning the ignition to RUN. The locks
will automatically lock and unlock to indicate you
are leaving the program mode. If the lock/unlock
switches are not pressed while in the programming
mode, the auto lock/unlock setting will not be
modified.
2-10
2003 - Sonoma OM

Retained Accessory Power (RAP)
Your vehicle is equipped with a Retained Accessory
Power (RAP) feature which will allow certain features of
your vehicle to continue to work for up to 20 minutes
after the ignition key is turned to OFF.
Your radio, power windows, sunroof and overhead
console will work when the ignition key is in RUN or
ACCESSORY. Once the key is turned from RUN
to OFF, these features will continue to work for up to
20 minutes or until a door is opened.
Starting Your Engine
Automatic Transmission
Move your shift lever to PARK (P) or NEUTRAL (N). Your
engine won’t start in any other position–that’s a safety
feature. To restart when you’re already moving, use
NEUTRAL (N) only.
Notice:Don’t try to shift to PARK (P) if your
vehicle is moving. If you do, you could damage the
transmission. Shift to PARK (P) only when your
vehicle is stopped.
Manual Transmission
The gear selector should be in neutral and the parking
brake engaged. Hold the clutch pedal to thefloor
and start the engine. Your vehicle won’t start if the clutch
pedal is not all the way down–that’s a safety feature.
Starting Your VORTEC™2200 L4
Engine
1. With your foot off the accelerator pedal, turn your
ignition key to START. When the engine starts, let
go of the key. The idle speed will go down as
your engine gets warm.
Notice:Holding your key in START for longer than
15 seconds at a time will cause your battery to
be drained much sooner. And the excessive heat
can damage your starter motor. Wait about 15
seconds between each try to help avoid draining
your battery or damaging your starter.
2. If it doesn’t start, wait about 15 seconds and try
again to start the engine by turning the ignition
key to START. Wait about 15 seconds between
each try.
When your engine has run about 10 seconds to
warm up, your vehicle is ready to be driven. Don’t
“race”your engine when it’s cold.
If the weather is below freezing (32°For0°C), let
the engine run for a few minutes to warm up.
2-22
2003 - Sonoma OM

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 position locks your rear wheels. It’s the
best position to use when you start your engine because
your vehicle can’t move easily.
{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brakefirmly 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“Shifting
Into Park (P)”in the Index. If you’re pulling a
trailer, see“Towing a Trailer”in the Index.
2-25
2003 - Sonoma OM

Make sure the shift lever is fully in PARK (P) before
starting the engine. Your vehicle has an 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. SeeShifting Out of Park (P)
on page 2-35.
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,
seeIf You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-40.
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 into a drive gear while your engine is
“racing”(running at high speed) is dangerous.
Unless your foot isfirmly on the brake pedal,
your vehicle could move very rapidly. You
could lose control and hit people or objects.
Don’t shift into a drive gear 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.
2-26
2003 - Sonoma OM

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 button.
You must wait for the 4LO indicator light to stopflashing
and remain illuminated before shifting your transmission
into gear or releasing the clutch pedal.
If the 4LO button is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light willflash 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 button. While the 4LO indicator light isflashing, 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 button.
You must wait for the 4HI indicator light to stopflashing
and remain illuminated before shifting your transmission
into gear or releasing the clutch pedal.
If the 4HI button is pressed when your vehicle is in gear
and/or moving, the 4HI indicator light willflash 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 button. While the 4HI indicator light isflashing, 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.
2-31
2003 - Sonoma OM

Torque Lock
If you are parking on a hill and you don’t shift your
transmission into PARK (P) properly, the weight of the
vehicle may put too much force on the parking pawl in the
transmission. You mayfind it difficult to pull the shift lever
out of PARK (P). This is called“torque lock”To prevent
torque lock, set the parking brake and then shift into
PARK (P) properly before you leave the driver’s seat.
Tofind out how, seeShifting Into Park (P) on page 2-33.
When you are ready to drive, move the shift lever out of
PARK (P) before you release the parking brake.
If torque lock does occur, you may need to have another
vehicle push yours a little uphill to take some of the
pressure from the parking pawl in the transmission,
so you can pull the shift lever out of PARK (P).
Shifting Out of Park (P)
Your vehicle has an automatic transmission shift lock
control system. You have to fully apply the regular
brakes before you can shift from PARK (P) when the
ignition is in RUN. SeeAutomatic Transmission
Operation on page 2-25.
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 want. You must press
the shift lever button on the shift lever.
If you ever hold the brake pedal down but still can’t shift
out of PARK (P), try this:
1. Turn the key to OFF.
2. Apply and hold the brake until the end of Step 4.
3. Shift the transmission to NEUTRAL (N).
4. Start the vehicle and then shift to the drive gear
you want.
5. Have the vehiclefixed as soon as possible.
2-35
2003 - Sonoma OM

Use this memory function to save your seat cushion and
seatback settings by using the following procedure:
1. Adjust the driver’s seat to a safe and comfortable
driving position.
2. Press the SET button and then press and hold
button 1 (for Driver 1) for three seconds. A chime
will sound to let you know that the position has been
stored.
A second seating can be programmed by repeating
the procedure with a second driver and pressing
button 2 for three seconds.
When your vehicle is in PARK (P) for an automatic
transmission or the parking brake is engaged for
a manual transmission, press and release the numbered
memory button you just stored. The seat will move to
the set position. You will hear one chime.
Pressing the UNLOCK button of a keyless entry
transmitter will adjust the seat to the corresponding
stored memory position. You will hear one chime.Repeat Steps 1 and 2 to readjust the seat. The
transmitter need not be reprogrammed unless it needs
to correspond to the other numbered memory button.
If there is a third driver, use the seat adjuster switch to
adjust the seat.
Pressing any of the seat adjuster switches, the SET
button or pressing the desired memory button twice will
cause the seat to stop moving.
If you press the numbered button to adjust the seat and
start the vehicle while the seat is still adjusting,
adjustment will pause while the ignition is in START.
Adjustment will resume after the ignition is in RUN.
Setting the seat memory function for a particular driver
will also personalize the radio station presets that have
been selected. Each time the driver sets this function, the
respective radio station presets will also be retained.
2-55
2003 - Sonoma OM