Remove the rear bumper.
Disconnect the 2P connector (A) from the rear bumper LF antenna (B).
Remove the two bolts and the rear bumper LF antenna.
Install the antenna in the reverse order of removal.
Honda Odyssey Service Manual > HondaVAC™ System Description: Sound Pattern of the Buzzer Pattern 1 ONOFF120±12 ms880±88 ms1000±100 ms Pattern 2 OFFON3000±300 ms ...