PRAM:
http://macs.about.com/od/usingyourmac/qt/Reset-Pram.htm
This might be related to Yosemite though. My girlfriends' Macbook Pro (Late 2012 or early 2013, I don't remember..) would consistently crash, reboot, or fail to resume from suspend. After 2 motherboard replacements, Apple gave her a brand new macbook pro. I'd take it into Apple and see what they say if you're near a store, and especially if you have AppleCare.