I have a 03 TL ES Magna with high sensitive theft alarm. Even lift sound can trigger that and caused flatten battery. Anyone have the same problem? Can anyone tell me how to disable it? Should I install a aftermarket alarm?

Normally you don't even know it's there. Yours is obviously having a problem.

The most common fault with these is the bonnet switch if it's the factory alarm. Usually if you space it up a bit higher it will fix the issue so that the bonnet pushes the switch further in.

I doubt it's the cause of your flat battery though.

Thanks lathiat , but where is the bonnet switch and any further details? I means caused flatten battery that alarm is always activated until battery is flatten.

Two questions:
Can you please write like an adult?
Do you know if you have an aftermarket alarm system fitted to your car?

I'm not sure what you mean by a lift sound.

Apologies for my words. I am a green hand at the auto stuff. And I am 100% sure there is only factory alarm in my car. When I parked in the apartment parking lot, the alarm always is triggered by lift sound such like "ding-dong, ding-dong" (My lot is close to lift). In other words, the alarm is so sensitive that can be triggered by any audible sound.

I just adjusted bonnet swtich. The alarm seems to work normally.