Check out this post: http://www.subarufor...e-back-13202/.
According to ferret (#7);
"This is common. Remove your grill and unplug the sonealert (beeper). It's mounted front and center to the center upright bracket. Dry out the connector and apply a coating of dielectric grease to it and put it back together.
Some moisture, salt ( allowing conduction ) or other matter allowing the water to conduct, gives a low resistance path to the ground. So the sonealert makes a low volume, high pitch noise until the connector drys off again."
or this post: http://www.subarufor...llo-help-25903/
again ferret to the rescue:
"Look in the manual for replacing one of the bulbs in the headlight. It has How to remove the grill.
The 'sonealert' ( Beep Beep ) when you lock the doors has a high resistance to ground thru it's connector from salt and water. It's
mounted front and center behind the grill, on the center vertical upright. Simply disconnect the connector, clean it thoroughly, coat it with some Dielectric grease, and put it all back together.
Common problem .... IF you have GOOD Young Ears !!!! I can no longer hear the high pitch when someone comes to me with the problem."