Resetting the alarm

Hello,

Disconnect the battery For 30 minutes, then hook it back up again.

https://www.2carpros.com/articles/how-to-replace-a-car-battery

Close all doors, engine hood and luggage compartment door (trunk lid) and lock the car wait 30 minutes and unlock the drivers door with the key or remote this should work.

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please let us know if you need anything else to get the problem fixed.

Cheers, Ken

Doors must be closed and locked.

See pic

No you need a pro to read any codes as the code readers won't read any thing other than engine/trans and some can read abs. So it will have to go to a service center

CHECKING THEFT DETERRENT SYSTEM WARNING (ALARM) OPERATION
Ensure theft deterrent system is set and indicator light is blinking. When hood is opened or any door is unlocked without using key, vehicle horns and theft deterrent horn will sound, and headlights and taillights will flash for approximately one minute. If doors are not locked when alarm is sounding, theft deterrent system will repeat door locking operation every 2 seconds during the one-minute alert time.
CANCELING THEFT DETERRENT SYSTEM SETTING (ALARM SOUNDING)
When system is set (armed) and the alarm is sounding, use one of the following methods to cancel the system setting:
Unlock left or right door with key.
Unlock doors with wireless door lock control system.
Insert key into ignition cylinder and turn to ACC or ON position.
Wait approximately one minute after alarm has sounded. After one minute, theft deterrent system will automatically reset in about 2 seconds if all doors are closed.

Disconnect theft deterrent ECU connectors. Measure voltage or resistance between following theft deterrent ECU connector T3 terminals. See Fig. 1. If voltage or resistance is not as specified, repair wire harness or replace components as necessary. If voltage and resistance are as specified, theft deterrent ECU may be faulty.
T3-1 & Ground
With ignition switch in ST position and shift lever in "P", voltage should be 10-14 volts.
T3-2 & Ground
With ignition switch in ON position, voltage should be 10-14 volts.
T3-3 & T3-4
With ignition switch off, resistance should be less than 50 ohms.
T3-5 & T3-16
With luggage compartment door switch "pulled", voltage should be 10-14 volts.
T3-5 & T3-16
With luggage compartment door switch not "pulled", voltage should be less than one volt.
T3-6 & T3-16
With key inserted into key cylinder, resistance should be less than one ohm.
T3-6 & T3-16
With key not inserted into key cylinder, resistance should be one megohm or more.
T3-7 & T3-16
With passenger's door unlock detection switch on, resistance should be less than one ohm.
T3-7 & T3-16
With passenger's door unlock detection switch off, resistance should be one megohm or more.
T3-8 & T3-16
During all conditions, voltage should be 10-14 volts.
T3-9 & T3-16
Resistance on indicator light circuit should be less than one ohm.
T3-10 & T3-16
With door key lock and unlock switch in unlock position, resistance should be less than one ohm.
T3-10 & T3-16
With door key lock and unlock switch off or in lock position, resistance should be one megohm or more.
T3-11 & T3-16
With driver's door unlock detection switch on, resistance should be less than one ohm.
T3-11 & T3-16
With driver's door unlock detection switch off, resistance should be one megohm or more.
T3-12 & T3-16
With passenger's door open detection switch on (door open), resistance should be less than one ohm.
T3-12 & T3-16
With passenger's door open detection switch off (door closed), resistance should be one megohm or more.
T3-13 & T3-16
With driver's door open detection switch on (door open), resistance should be less than one ohm.
T3-13 & T3-16
With driver's door open detection switch off (door closed), resistance should be one megohm or more.
T3-14 & T3-16
With door key lock and unlock switch on (lock position), resistance should be less than one ohm.
T3-14 & T3-16
With door key lock and unlock switch off (unlock position), resistance should be one megohm or more.
T3-15 & T3-16
With key lock and unlock switch on (unlock position), resistance should be less than one ohm.
T3-15 & T3-16
With key lock and unlock switch off (lock position), resistance should be one megohm or more.
T3-16 & Ground
During all conditions, resistance should be less than one ohm.
T3-17 & T3-16
With door lock control switch on (lock position), resistance should be less than one ohm.
T3-17 & T3-16
With door lock control switch off (unlock position), resistance should be one megohm or more.
T3-18 & T3-16
With door lock control switch on (unlock position), resistance should be less than one ohm.
T3-18 & T3-16
With door lock control switch off (lock position), resistance should be one megohm or more.
T3-19 & T3-16
With luggage compartment door opener switch on, resistance should be less than one ohm.
T3-19 & T3-16
With luggage compartment door opener switch off, resistance should be one megohm or more.
T3-20 & T3-16
During all conditions, voltage should be 10-14 volts.