I have a 2008 IS250 AWD and I have had the same problems - several times. The first time it happened was in March/09. I would drive home from work about 25 km, leave the car running while I ran into get the mail and when I got back in the car the Service Engine light, traction control light, information warning light and Check VSC would all be on. I took it to the dealer the next day and they could find nothing wrong and just reset the diagnostic computer. Then a couple of weeks later the exact same thing happened again under the same circumstances. This time the dealer did find a code (they didn't tell me what it was) which indicated something wrong with the fuel (I only use premium). For the next several months everything was OK. Then on 12/28/09 I drove about 25 km, stopped at a traffic light and the same diagnostic lights came on again. Over the next 2 days which included several engine start/stops the lights remained on. Then on the 3rd day the lights did not come on after starting the car. All OK for about a week and then the lights came on again. Took the car to the Toyota dealer (no Lexus dealer where I live) and they got 2 codes out of the computer P0172 and P0175. They called Lexus and were told Lexus knows about the problem and they need to make a program change to the computer. So now I have to drive 3 hours to the Lexus dealer in Toronto to get the fix done.