Siren noise After 15 minutes of driving starts the front body of the scooter making some kind of alarm or buzzer sound.

. It could possible be that the alarm IS going off, but for some reason full current is not getting to the buzzer or the buzzer is broken. It could also be as you said a current leak. Generally these systems are set up with a float to turn pump on /off and a second float to activate high water alarm. the floats are either on or off. It might be possible that you have an electrical level sensor that is malfunctioning. Be careful if you work on it.

The alarm beep was a option that was dealer installed. It has a factory option installed at the dealer. The siren itself is up front under the right front(passenger side ) of the cowl. If you remove the cover for the micro filter and the micro filter and look under cowl you should see the siren. If it is not there then you would have to buy the alarm system and have it installed and coded to the vehicle. If it is already there then it may have to be coded by the dealer to make it sound when locking and unlocking thru flash coding. Did it ever make a sound? If so it is there and may be a bad siren?

try disconnecting the battery for a couple of minutes so the electrical system reboots itself with a clean start. That might fix it. IU would give it 10 to 15 minutes disconnected before reconnecting and trying it. Further to that i would say take it to the dealer and send the bill to the place that did your oil change

The siren should not receive any power when in idle mode (non alarmed state). If you hear any noise, it receives some kind of low voltage. Is it powered straight from the panel or with external power supply and aux. relay? In any way - use a volt meter and measure across the sirens power terminals. If you have any voltage present check the source.

What's kind of noise and is it coming from the body or the engine? As far as the jerking may need a front end alinement or new struts

Sound like the siren. check the connections at the siren. If the connections are good and the system is sending a signal then, you may need to replace it.

A beep tone will activate when selecting the HWS buzzer
alarm.
The alarm beep will become shoter and shoter every
15 seconds for one minute followed by one minute silence
before repeating the cycle.
The HWS alarm will sound for one hour until turning off by
pressing the Power button. Press the Power button whilst
the alarm is activated will cancel the alarm for 24 hours.
1. The HWS buzzer alarm can be set either radio is on or
off.
2. Press and release the HWS buzzer alarm button
, the symbol will flash.
3. During the symbol flashes, long pressing the
button for more than 2 seconds followed by a beep
and display Hour digit will flash.
4. Rotate Tuning Control to select required alarm hour,
then press time set button again. The minute
digit will then flash.
5. Rotate Tuning Control to select required alarm minute,
the press time set button again to complete HWS
buzzer alarm setting.
6. Press and hold down buzzer alarm button for
more than 2 seconds followed by a beep to switch on
or off the HWS buzzer alarm.
Display will appear when buzzer alarm has
been set.

putting unfrozen food in a freezer can raise the temp to cause it to go off allow 24 hours for it to stop if it dont replace the buzzer

under the ecu on the right hand side inner wing ,near the fuse box is the siren,un plug and remove the ecu then un plug the siren remove it by any means I had to pry mine off it has its own battery pack inside,I binned mine cos it doesn't affect the running of the Jeep hope you got sorted

Open wiring area up and find where noise is coming from. There is a electronics board in some fans that might have a warning buzzer of some kind.