What does it mean when the battery icon is blinking on the LCD panel?

If the <π> icon blinks on the LCD panel, the battery level is very low and you should replace the batteries with new ones. A proper exposure can still be obtained as long as the shutter releases, but film advance and auto rewind might stop midway or not work at all. After replacing the batteries, film advance will be possible and film rewind can resume by pressing the rewind button. (Page 5)