Lexus has a TSB regarding the ISC learning procedure. Supposedly the idle speed will be off if this is not done after the battery goes dead or is disconnected. Apparently, mileage may suffer if this is not done. ___________________________________ Here's the TSB - EG010_05.pdf The TSB says you need to hook the vehicle up to the Lexus diagnostic tester (which the dealer has and you don't) but I found a post here http://www.greenhybrid.com/discuss/f31/400...ification-8126/ that shows it can