I changed the battery in my 2000 Honda Accord and the alarm seems to be set to another mode. From what I can tell it is in a mode called "last door arming" how can I set it back to the factory setting without going back to the dealer?

(before the problem started the alarm used the car horn, now it uses the loud speaker and sounds like an after market system)

 

I didn't even know we could change the sound or action of the OE alarm.
Are you sure one of the horns isn't just gone bad.

I've swapped the battery a few times an the alarm is still like OE for me.

 

are you sure it's honda alarm ? only EX and SE's came with factory alarms the other are usally aftermarket ones installed at the dealer or a dealer installed honda alarm it's like the aftermarket one but plugs into the car .