Took my Powerboost in to get the transmission oil changed. When the mechanic (original dealer) went to start it....... No go. He spent nearly 12 hours trouble shooting to no avail. They had tried disconnecting the 12v battery to reset things but no effect. I had noticed that there is a small lead acid battery in the rear seat area, pax side. In my experience this is a "Keep alive" battery. They have very limited circuits they "keep alive." Mentioned this to the mechanic. In the end they disconnected the main 12v battery and the small 12v battery, let it sit overnight... And voila: it started and ran fine... So, if you need to do a computer reset, don't forget the keep alive battery, it needs to be disconnected also.