Cannot unlock door when battery dead

are you irish ?? thats your alarm light warning and its meant to blink to warn any would be tea leaves that this vehicle is alarmed with a chipped key ,actually you better off leaving it unlocked as then the windows will not get broke by a junkie looking to see if you have any emergency cash in the glove box

Have you replaced the battery lately? If so , you could have a bad battery in your key. It is a small microchip in some cares and will effect unlocking and starting the car if the battery is weak or dead.

Have you tried a new battery in the remote, or do you have a second remote you can test. Either your remote is worn out or the battery is dead.
Once you lock the car with your remote it will active the alarm and if you use your key it won't deactive the alarm only your remote will, on some cars putting the key in the ignition will deactive it.
If you can deactive your alarm with your remote and can just manualy lock and unlock your doors and that should prevent your alarm from going off until you get a new remote or battery.

the button in the fob may be stuck connecting the circuit, remove the battery and reconnect if the alarm goes off again it could be because of this.

You can disengage alarm with a remote if you have one otherwise, close bonnet, all doors and lock the car by turning key completely to the left and right few times and do the same to unlock. This will dead lock and unlock the car. When you hookup the battery make sure you connect red wire first and then the black one.

Battery Constant 12v+ Positive Wire (+): Black/Yellow
Battery Constant 12v+ Positive Wire Location: Ignition Switch Harness

Starter Positive Wire (+): Blue/Red
Starter Positive Wire Location: Ignition Switch Harness

Ignition Positive Wire (+): Red
Ignition Positive Wire Location: Ignition Switch Harness

Accessory Positive Wire (+): Red/Yellow
Accessory Positive Wire Location: Ignition Switch Harness

Parking Light Positive Wire (+): Red
Parking Light Positive Wire Location: Low In Drivers Kick Panel

Power Door Lock Negative Wire (-): Add Actuator. This vehicle uses a central door locking system. When connecting a keyless entry, you will need to add a door lock actuator and some units will also require (2) extra relays.
Power Door Lock Negative Wire Location: To Drivers Door Only

Power Door Unlock Negative Wire (-): Add Actuator. This vehicle uses a central door locking system. When connecting a keyless entry, you will need to add a door lock actuator and some units will also require (2) extra relays.
Power Door Unlock Negative Wire Location: To Drivers Door Only

Door Trigger Negative Wire (-): Red/White
Door Trigger Negative Wire Location: In Black Plug, Above Hood Release

Domelight Supervision Wire: Use Door Trigger, Requires Relay
Domelight Supervision Wire Location: N/A

Horn Negative Wire (-): Red/Green
Horn Negative Wire Location: At Steering Column Harness

Tachometer Wire Negative Wire (-): Black/Blue
Tachometer Wire Negative Wire Location: At ECM, Under Drivers Side Dash

Brake Light Positive Wire (+): White/Black
Brake Light Positive Wire Location: At Switch Above Brake Pedal

CODE ALARM SYSTEM

Used on:
Impreza 1996-2001
Legacy 1995-1999
Forester 1998-2000

Battery GP-23A

Lock: Left button will lock all doors. Double chirp indicates locked.
Unlock: Right button will unlock driver's door only. Hold unlock button app 6 seconds, it will unlock all doors including rear gate. Single chirp indicated unlock.
If the car chirps or lights flash 4x the alarm was triggered.
Panic. Press both buttons to activate emergency honk and flashing lights.
Valet mode: With optional alarm onlyPress the red alarm button on the left of the steering wheel. The light will quickly double flash. To re-set back to normal mode, press the red alarm light button again

Battery failed and lights flashing?
Parking lights will flash when the vehicle's battery is disconnected and reconnected.
To stop lights from flashing, either:
Press remote transmitter "UNLOCK" button once OR turn the ignition switch to the "ON" position and press programming button for one second (see below).
The vehicle interior (courtesy) light and door open warning light (DOOR AJAR indicator) will then illuminate for 60 seconds when the ignition is turned off, or until the doors are locked with the remote transmitter. Yes, the dashboard instrument panel lights will flash when the parking lights flash.

Programming or Overriding the Alarm when you have lost the remote
Open driver's door.
Turn ignition key to 'On'
Press and *hold programming button* in (see diagram, button under dashboard)
After 15 seconds the the door locks will cycle 3 times. Do not release Programming button.
Press lock (left) button the remotes to be programmed. The door locks will cycle one time. Exit programming mode by releasing Programming button under dashboard and turning key to off.

Code Alarm Programming Button is under dashboard on the kick panel by the driver's left knee, left of the steering column. If you can't find it, it might still be tucked up in the wiring harness higher up in that same general area. The botton is recessed in a plastic ring (see diagram).
This button must be pressed while programming remotes or if the battery was disconnected and the lights are flashing.

Programing the button REMOTE portion of the key is simple.
You do need 2 keys. You must be able to lock the drivers door and have the red led alarm light next to the lock button blink. If it does not blink, the alarm does not know the door is closed and will not go into program mode. Put one key in the ignition switch, turn on, do not start engine. Close the door, use 2nd key, turn door lock and hold in lock position for 10 seconds. Release key to neutral position.
Press a button on the remote, within 2 seconds press the same button again, the turn signal lights will flash,
this indicates your remote matches the car system and is now recognized. Unlock door remove key from ignition.
So don't pay extra 99 cents to $5 for these instructions in hopes of getting the KEY to function with the car.
Instructions are only for the keyless remote, not the key.

you need to disarm the alarm. unplugging batt. or dead battery being jumped sets of the alarm not all alarms make noise
use remote to lockand then unlock doors need to be closed
or lock then unlock door with key if it dont reset then try passenger door

security ----encrypted software dealer only