Related question, which does not seem to be answered by the manual:

Can you disable the feature which automatically locks the doors when
you press your lock switch with the door ajar and ignition off? (that
lock that engages after 10 seconds)  I realize I simply do not have to
use that feature, but I got in the habit of doing it, and sometimes I
set my keys down in the car and disaster strikes (though I've always
been within a hitched ride of my other set of keys).

In addition, it seems like you should be able to change the unlock mode
so that you unlock all the doors with the first press of the unlock
button.

Document ID# 719130
2002 Oldsmobile Alero
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Power Door Locks Description and Operation

Door Lock System Components
The power door lock system consists of the following components:

Driver door lock switch
Front Passenger door lock switch
Body Control Module (BCM)
Relays: Driver Door Unlock -- on vehicles with RFA, Door Unlock, and Door
Lock
Door Lock fuse 15A
Door Lock System Controls
The power door lock system can be controlled by any of the following:

A power door lock switch activation
A keyless entry command -- if equipped with keyless entry
Driver and Passenger Door Lock Operation
When any of the door lock switches is pressed to the lock position, the BCM
door lock/unlock signal circuit changes from an idle voltage of ~3.4 volts
to 0.0 volts generating a lock command. The BCM then applies battery
positive voltage to the Door Lock Relay, which in turn applies battery
positive voltage to the Door Lock Actuator lock circuit of all the Door Lock
Actuators. Since the Door Lock Actuator unlock circuits are held to ground
through the resting Door Unlock Relay(s), the actuators execute the lock
command, locking the doors.

The lock function can also be accomplished by the BCM having received a
keyless entry door lock command, if the vehicle is equipped with keyless
entry.

Driver and Passenger Door Unlock Operation
When any of the door lock switches is pressed to the unlock position, the
BCM door lock/unlock signal circuit changes from an idle voltage of ~3.4
volts to ~1.7 volts generating an unlock command. The BCM then applies
battery positive voltage to the Door Unlock Relay and the Driver Door Unlock
Relay when equipped with keyless entry, the relay(s) in turn apply battery
positive voltage to the Door Lock Actuator unlock circuit of all the Door
Lock Actuators. Since the Door Lock Actuator lock circuits are held to
ground through the resting Door Lock Relay, the actuators execute the unlock
command, unlocking the doors.

The unlock function can also be accomplished by the BCM having received a
keyless entry door unlock command, if the vehicle is equipped with keyless
entry. Keyless entry personalization allows the driver door to be unlocked
individually before unlocking the passenger doors. When this feature is
active, the BCM will require a repeated unlock command to unlock the
passenger doors.

Lockout Prevention
The BCM does not allow the driver door to stay locked when you press LOCK on
either door lock switch with the lockout prevention feature active. The BCM
activates the lockout prevention feature when the following conditions
exist:

A vehicle door is open. An open vehicle door sends a ground signal to the
BCM door ajar switch input.
The key is fully inserted in the ignition cylinder. Full insertion of the
key sends a signal to the BCM key in ignition input.
Lockout Prevention Override
The BCM overrides the lockout prevention and locks all of the doors. This
feature occurs when you press the lock switch on the key fob.

Last Door Locking
This feature prevents the doors from locking until after all of the doors
have been closed for approximately 10 seconds. The BCM activates the last
door locking feature when a door ajar signal is present and a door lock
switch lock input is received by the BCM.

Automatic Door Lock/Unlock
The automatic door lock/unlock function is a Vehicle Personalization feature
with the following four programmable modes of operation:

The automatic door lock feature is disabled.
All of the doors lock when the vehicle is shifted out of Park with the
ignition ON.
All of the doors lock when the vehicle is shifted out of Park with the
ignition ON, and all of the doors Unlock when the vehicle is shifted into
Park.
All of the doors lock when the vehicle is shifted out of Park with the
ignition ON, and only the driver door Unlocks when the vehicle is shifted
into Park.
For information on programming the automatic door locks, refer to Vehicle
Personalization in Personalization.

Unlock After Air Bag Deployment
This feature will unlock all of the vehicle doors 15 seconds after air bag
deployment.

Document ID# 735348
2002 Oldsmobile Alero
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Vehicle Personalization
Modes of Operation
Automatic Door Locks (Manual Trans)
The following are the modes of operation for the automatic door locks
feature:

Mode 1: All of the doors lock when the vehicle speed exceeds 8 km/h (5 mph).
All of the doors will unlock when the transaxle is shifted into REVERSE (R)
and the key is turned to OFF. Mode 2: if equipped with RKE All of the doors
lock when the vehicle speed exceeds 8 km/h (5 mph). Only the driver door
unlocks when the transaxle is shifted into REVERSE (R) the key is turned to
OFF.
Mode 3: All of the doors lock when the vehicle speed exceeds 8 km/h (5 mph).
No automatic door unlock.
Mode 4: No automatic door lock or unlock.
Automatic Door Locks (Automatic Trans)
The following are the modes of operation for the automatic door locks
feature:

Mode 1: All of the doors lock when the vehicle is shifted out of PARK. All
of the doors unlock when the vehicle is shifted into PARK and the key is
turned to OFF.
Mode 2: All of the doors lock when the vehicle is shifted out of PARK. Only
the driver door unlocks when the vehicle is shifted into PARK and the key is
turned to OFF.
Mode 3: All of the doors lock when the vehicle is shifted out of PARK. No
automatic door unlock.
Mode 4: The automatic door lock feature is disabled.
Programming Features
Enter Programming
To enter the programming mode, perform the following actions:

On a vehicle with a manual trans, place the trans in REVERSE. Apply the park
brake.
Close all of the doors.
Turn the ignition to the RUN position.
Automatic Door Locks
Continue with the following steps in order to personalize the automatic door
locks:

Press hold the LOCK button on the power door lock switch for 10  seconds.
The vehicle will chime with the number of chimes corresponding to the
current mode. Refer to Automatic Door Locks modes.
Press and hold the LOCK button on the power door lock switch for 10  seconds
again in order to advance to the next mode. The vehicle will chime with the
number of chimes corresponding to the mode.
Continue to press and hold the LOCK button on the transmitter until the
desired mode is reached.
Remote Activation Verification
Continue with the following steps in order to personalize the horn for the
remote activation verification feature:

Press and hold the power door lock switch in the UNLOCK position for 10
seconds. The horn will chirp when the horn setting for the remote activation
verification has changed between disable and enable.
Press and hold the power door lock switch in the UNLOCK position for 10
seconds again to change the horn setting back to the original setting. The
horn will chirp when the horn setting for the remote activation verification
has changed.
Exit Programming
Any of the following list of events will cause the programming sequence to
be terminated:

The ignition is moved from the RUN position.
The vehicle is shifted out of REVERSE for vehicles with a manual trans.
The park brake is released for vehicles with a manual trans.
Chime Level Adjustment
In order to adjust the chime level, perform the following steps:

Turn the ignition ON.
Turn the radio OFF.
Press and hold the radio push-button 6 until either LOUD or NORMAL appears
on the radio display. The chime sounds 3 times for each volume change.
To toggle the setting, press and hold the radio push-button 6 again.
Additional Information
For more information on the personalization features, refer to one of the
following description and operations:

Refer to Power Door Locks Description and Operation in Doors for more
information about the automatic door lock feature.
Refer to Keyless Entry System Description and Operation in Keyless Entry for
more information about the remote activation verification feature.
Refer to Theft Systems Description and Operation in Theft Deterrent for more
information about the Content Theft Deterrent feature.
Refer to Audible Warnings Description and Operation in Instrument Panel,
Gauges and Console for more information about the Chime.

Just purchased a 2002 Alero 3.4.  The all-door lock switch (on drivers
door, next to widow switches) only unlocks drivers door, but locks ALL
doors.  I've also heard this is a "smart" system - something called
last-door-locked.

Also heard this system can be programmed?

Is there a remote-key unlock/lock feature on this car - the one key we
were given is plain w/no electronics.

Without an owners manual, can someone help us diagnose this?

Much obliged -