Answer Back (Horn Signaling) On/Off Selection: Notes
WARNING: This page is about a different car, the 2002 Subaru Outback and 2002 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Push the transmitter's UNLOCK/DISARM button. Then, push the transmitter's LOCK and UNLOCK buttons simultaneously for more than 2 seconds to activate the answer back function. Push them again to deactivate it.