From the owners manual:
- Tire Fill Alert
This feature notifies the user when the placard tire pressure is attained while inflating or deflating the tire.
The horn will sound once to let the user know
when to stop filling the tire, when it reaches recommended pressure.
The horn will sound three times if the tire is over- filled and will continue to sound every five seconds if the user continues to inflate the tire.
The horn will sound once again when enough air is let out to reach proper inflation level.
The horn will also sound three times if the tire is then underinflated and will continue to sound every five seconds if the user continues to deflate the tire.
Look at the placard in your door jamb. Whatever number is listed there is the number at which the tire fill system will honk to let you know its arrived.