My truck recently started running rough and shifting gears when acclerating even rougher. The only code it's showing is the P6011 FICM one. I had both batteries and the altenator tested with everything showing ok. My question is...is their any possibility that it could be anything other than the FICM if thats the only code? and with me being without a voltmeter or tools should I just bite the bullet and order a new one? And whats the difference between a $400 ficm from a vendor or a $200.00 one guarenteed off of a reputable seller on ebay?