Alarm won't disarm with key only

I do know that if you put the key in the ignition after you open the door and cycle the key from off to on 3 times fast within 5 seconds the alarm will disarm. Whether or not it is for good is unknown since you have to lock your doors again at some point. Your remote is discontinued by Subaru, but the the newer remote for the 2005 to 2007 models will work on your car, unless you already have one. I hope this info helps!

Put key in ignition, turn all the way forward, but not trying to start. Let alarm cycle 2 times, when it stops the 2nd time, remove key and alarm should be disarmed. This will only work if it is a factory alarm.

Your Sonata is equipped with a "Keyless Entry & Burglar Alarm" system. When the Burglar Alarm is activated, it KILLS the starting system through the used of a relay called the "Burglar Alarm Relay". This mode prevents engine starting with the key.
Solution #1
Disarm the system with the Keyless Remote (key fob) If you don't have this remote (or its battery is dead) replace the battery & try disarming again.
Solution #2
Enter the vehicle & insert the key in the ignition and turn the ignition switch to 'RUN'. Wait 3 to 5 minutes until the alarm stops. You should then be able to start the engine.

Have a qualified/certified Hyundai Service Technician properly diagnose this issue.

The 'Keyless Entry & Burglar Alarm System" is activated. You must 'Disarm' the system using the Keyless Entry Remove (Key Fob) to "Reset" the system. The reason the engine won't start is due to the burglar alarm - it has a "Starter Kill" circuit which is activated when the alarm is activated. The alarm must be DEactivated to DEactivate the 'Starter Kill' circuit.
Another way to start the engine is to get in the car, put the key in the ignition and turn it to 'ON" and wait 3 to 5 minutes until the emergency flashers stop/turn off. Afterward, you should be able to start the engine. NOTE: This does NOT reset the burglar alarm. It will go off again when you enter the vehicle without using the remote/key fob.

Had same problem not to long ago~~~~ I have to check all 4 doors to be sure they are locked mainly the back 2 and then I went around to all 3 door locks & locked and unlocked a few times each... it was on passenger side when my light finally was deactivated... hope this helps you.. I haven't had any problems since ;0)

Just a quick note once you hook the battery back up try locking it and unlocking it from the drivers door, if that fails you might try the passenger door. I know on some chrysler products you have to lock and lock again to arm and unlock to disarm. I hope this helps.
Thanks,
Joey

Here is what I do on my 95 Cirrus I also do not have a keyless remote (well I do but is broke) and after frustation after frustation trying to disarm the factory alarm I find out that by unlocking the passenger front door with the ignition key from the outside will disarm it you may have to try few times before it's disarmed you need to make sure that the blinking red light stops blinking and all of the locks on all 4 door are up or unlocked, this is what I been doing for 3 years now and that's how I disarm the alarm on my car, I hope this helps.

lock with key,electric door lock button,or remote and alarm will set. to disarm you have to use the key or remote to open it.the reason it woulnt disarm from drivers door is either the door lock cylinder switch is broken or the wire to it in the rubber boot that connects the door and the body is broken.
the remotes are cheap and programing is easy,procedure in owners manuel something like lock drive door with elkect. lock switch with door open then push and hold unlock untill doors unlock then turn key off.you may have to fix that drive door lock cyl.switch first though mabee not dont know for sure

The Simple Act of Locking the Driver side Door WITH KEY Arm the Factory Alarm. And UNLOCKING Same Door with KEY Disarms it The FOB < Rmote for Alarm Just Honks Horn and Flashes Lights, But it Does the SAME ARMIND & DISARMING. I Hope this Helps You out !!

The ignition lock anti-theft switch (19A438) detects if the ignition key cylinder is broken or "slam pulled" during a theft. The ignition lock anti-theft switch is always monitored by the remote anti-theft personality (RAP) module. This allows the alarm system to be triggered in the case that the ignition lock anti-theft switch detects tampering of the ignition key cylinder (even in the event that the alarm is not active at the time).
Refer to the Section 501-14B for more details on the keyless entry remote transmitter (15K601).
The door open warning lamp switch (14018) communicates to the RAP module through the generic electronic module (GEM). This input to the RAP will cause the anti-theft alarm to be sounded if the anti-theft alarm was armed.
The door disarm switches are assembled into both LH and RH lock sets. The door disarm switch must be triggered before the mechanical lock unlocks. This is to prevent the anti-theft alarm from activating when it should have been disarmed.
The RAP module controls the anti-theft system and is the brains of the keyless entry system. The RAP module communicates with the GEM to request that the interior lights be turned ON/OFF with use of the keyless entry remote transmitter, and the GEM communicates to the RAP to inform when the door is opened. Refer to Section 418-00 for inter-module communication.
The RAP module has three wire connectors attached to it:

• The antenna for the keyless entry remote transmitter.
• 26 circuit connector (C256).
• 22 circuit connector (C257).

In addition to the perimeter alarm that uses the door open warning lamp switch, the RAP module also uses the ignition lock anti-theft switch and the autolock/relock feature to prevent theft of the vehicle. For a full description of the autolock/relock system, refer to Section 501-14B .
The THEFT LED is found on the instrument panel between the tachometer scale and the needle pivot point. The LED is illuminated during prearming and flashes when armed or triggered.
Prearming and Arming the System
The system can be armed if:

• The ignition is OFF.
• The PANIC alarm is OFF.
• All doors are closed.

There are two ways to prearm the system:

• Press the LOCK button on the transmitter.
• Open a door, press the power door lock button and close the door.

After 30 seconds the system will be armed and the theft indicator in the cluster will flash every two seconds.
Disarming an Untriggered System
An armed system will be disarmed with one of these valid actions:

1. Pressing the UNLOCK button on the transmitter.

1. Placing a key in the door and turning to UNLOCK.

1. Turning the key to RUN or ACC.

The anti-theft alarm can be triggered by the following conditions:

• The ignition cylinder is damaged with or without the RAP being armed.
• A door is opened without disarming the armed RAP module.

The remote transmitter can activate a panic alarm which is similar to an anti-theft alarm, but does not deactivate the starter or cause the theft indicator to flash.
Disarming a Triggered System
If the system has been triggered, (the horn honks, the lights flash, and an external starter interrupt relay is engaged), the system can be disarmed by:

1. Pressing the UNLOCK or PANIC button on the transmitter.

1. Putting a key in the door and unlocking the door.

1. Turning the ignition to RUN/ACC (Turning the key to RUN/ACC will not disarm an alarm that has been triggered by the ignition lock anti-theft switch.).