I think the dealer said it turned out to be the ECU(?) in the Sequoia. I certainly don't think I went over some oil or gravel or something, but if it had happened once, I'd probably just write it off to something like that. My VSC system actually triggered 3 different times within about 15 minutes with no visible reason why. This never happened in the first 1000 miles and then happened 3 times in 15 minutes in one trip, so I can't believe there isn't some problem with some component of the truck. The one thing I could think of and that I asked to the dealer to look into is that the truck had recently sustained some minor damage when it got hit in the left front fender/wheel by a drunk while it was parked (I know, my lucky month). It required filling/refinishing a body panel and a 2 wheel reallignment. I pointed this out to the dealer, as I thought it might have been something with the sensor on the tire near where the truck got hit, but the dealer said they looked and didn't see any problem.