I have 09 4.8. The SA states that have the approval to replace the wiring harness. The throttle body/wire harness has been replaced. Battery is brand new. I guess it could be alternator, but you would think they would have ruled it out. Another X5 was in for the same thing and BMWNA suggested the wiring harness replacement. The other vehicle is ok now. I should have the vehicle back by Tuesday. I keep you all posted.