parked and beeping in the night

Periodically, during the night, my 2004 Prius will emit 4 loud staccato beeps, hours apart (2am and 4 am last night). The fob is on the 3rd floor bedside table. Any ideas what it might mean?

When was the last time you replaced the 12V battery in your Prius?

Tom

The 12V battery is dying [as Tom suggested one minute ago]? Somebody is beaming microwaves at the car?

It's lonely.

Just to let the poor thing know you still care, hit the lock button once at 1:58 and again at 3:58, and everything will be fine.

My dealer warned me about this and said it's normal. He said the Prius checks itself sometimes 15 hours after use. Apparently more than a few owners have called the service department about it. I believe it had to do with the emissions function of the car.

This is bad information. The Prius does do some checks several hours after shutdown, but there are no loud beeps associated with these checks. Your dealer is misinformed.

Tom