I found this on the Canadian Toughbook page on Sunday. No clue why it's not on the .US site. It states that it improves stability issues while running on battery power. It applies to the MK1 and MK2.
What is the difference between the Embedded Controller and the BIOS?
http://pc-dl.panasonic.co.jp/dl/docs/063256?dc[]=002003&no=1&p1=211&score=1.0&sri=10322996&trn_org=2
What is the difference between the Embedded Controller and the BIOS?
http://pc-dl.panasonic.co.jp/dl/docs/063256?dc[]=002003&no=1&p1=211&score=1.0&sri=10322996&trn_org=2