We keep having the same sporadic problem with the VSC/VSC OFF lights coming on in our 99 ES300. Have had it happen a couple of times with the Check Engine light, then it goes off. Dealer also told us that they couldn't diagnose it if the light wasn't on - well it comes on and off randomly, so it's impossible to make an appt. to get it looked at. Has been happening off and on for over a year. Seems like some kind of wiring/sensor problem (apparently rather common because the Lexus folks just roll their eyes). My current theory I'm testing is that our turn signal which was doing its fast blink (indicating the bulb is going bad) sporadically too, may be related, so I'm seeing if it makes any difference since we replaced the turn signal bulb. Also going to see if it relates at all to the gas level in the car since some people seem to think that light gets triggered by an emissions sensor. On the other hand, we had a SAAB 9000 previously that had every imaginable electrical quirk, so this is really minor compared to it. Still, it continues to make me concerned that something might be actually wrong.
