Check engine alarm can't be resseted

Are you try with OBD scanner reader tool?

Connect an ammeter in series with the battery positive terminal and battery positive lead. With ALL systems off, including alarm, door lights etc and with doors closed you should have a reading of only 0.03 amps.I'm guessing that yours is higher as it sounds like you have a parasitic voltage drain.If indeed it is higher, then disconnect any alarm system first and check your amps again. Every time you disconnect something, go back and check your amps.Once you get your amp drain back to normal, then you have managed to disconnect the system responsible for the high current drain.
The most likely candidates are always the alarm system, then stereo, then GPS tracker. After that you will have to start pulling more fuses, one by one and letting the vehicle rest for a few minutes after each thing is disconnected before taking a reading.
BTW, if it is the alarm which is drawing a high amp drain, then it is more often than not the alarm siren back up battery which has failed.
Good luck.

Often an alarm system will register a low battery voltage and presume the vehicle's battery is being removed to prevent the alarm from going off. They will then begin flashing and or sounding the horn.
In your case, I would presume that the battery voltage is too low which may indicate either a failed battery, or a parasitic voltage drain.

First, get the vehicle started, and run the vehicle for a good twenty or so minutes to get some charge to the battery. If you don't want to waste fuel however doing this, then I suggest using any battery charger, as all we want to do is get some voltage back in the battery. If you are using a charger though, then charge on a lower voltage setting overnight.

Once you have the battery charged, run off any surface charge by turning the vehicle lights on for a minute, then turn them off again.

You need an ammeter for this next part:


Disconnect the battery positive terminal and connect the ammeter in series with the battery and positive lead.
DO NOT ATTEMPT TO START THE VEHICLE!

With all vehicle systems off, the key out, doors closed and alarm 'OFF', bonnet close switch depressed, or bonnet/hood clasp closed (need a screwdriver), take a reading from the ammeter.
After probably no more than twenty minutes, the ammeter should be reading 0.03 amps and not much more. Anything like 0.5 or 1 amp means you have a battery drain.
If this is the case, then start by disconnecting the alarm system. If the alarm system has it's own separate speaker/horn, then disconnect this first. Many of these horns have backup batteries, which only last three or four years before they fail, which causes them to constantly draw from the vehicle battery and then flatten it when parked.
Every time you disconnect an item or system, check that ammeter again to see if the amps have returned to normal. Pull fuses one by one, checking the ammeter each time for any change until you find the system which is causing a drain, then attend to that system.

If your amps are normal however and your battery is still loosing charge when parked for any short length of time, i.e. a few days or so, then your battery is at fault and requires replacement.

Just before changing your battery, do one last check, which is with the vehicle running. You need to reconnect any battery cables, and start the vehicle. Using the voltmeter once more, check the voltage across the terminals with the engine running. This is your charging voltage and it should go up to around 14 volts if revving the engine slightly. If still around 12 volts only, then you have a charging issue, which is probably the alternator.

Have you had the alternator checked? may not be charging the battery.

I doubt the service person did anything wrong. In today's cars with both engine and body computers, jump starting a car can be risky.
You're better off having the battery charged for an hour or so then trying to start it.
You may have to have the body computer scanned and possibly flashed to get everything working again. The body computer controls everything you mentioned. It could have lost some of the factory programming when the system was dead.

Hello! There is a Hood Switch designed to operate the Alarm If the hood is opened when the car is locked with alarm set...The Hood Switch is affected by heat from the engine plus the ambient temperature...The wire colors on the two pin switch connector are...Black/Pink and Black...Replace the switch OR clip a wire across those two pins which tells the system the switch is permanently closed...If this doesn't work, try disconnecting the connector which leaves the switch permanently open...I believe if you short out the switch the system won't know and the trouble will be removed...Guru...saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

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.

First of all, has the burglar alarm been activated? If so, you can enter the vehicle with the key, put the key in the ignition and turn it to 'RUN' or 'ON" and then wait 3 to 5 minutes for the burglar alarm to stop. You should then be able to start the engine. You still need to have a qualified/certified Hyundai Service Technician properly diagnose the problem with the remote (Keyless Entry & Alarm System).

The 2003 Sonata is equipped with a 'starter KILL' burglar alarm system with disables the starting system (using a N/C 'contacts' configuration instead of a N/O contacts configuration). N/C=Normally closed, and N/O=Normally open contacts. When the alarm goes off with a MY Sonata, the only way to DISARM it is with the key fob (remote) originally programmed for it (unless you purchase a new remote & have it programmed for the vehicle at an authorized Hyundai Service Department). NOTE: So long as the keyless entry & burglar alarm system is functioning/operating normally, the alarm will keep going off and the STARTER KILL function will still prevent you from starting the vehicle. One option is left without purchasing a new remote and having it programmed.
1. When the alarm goes off, get into the vehicle and insert the ignition key into the ignition.
2. Turn the key to the 'RUN' position (NOT the ACC position) and wait for the alarm to STOP (usually about 3 to 5 minutes).
3. The engine should then start using the ignition key.

If this procedure doesn't work, the problem will need further diagnosis by a qualified/certified Hyundai Service Technician.

Hope this helps