My VSC warning light, along with the TRIANGLE OF DOOM and the squiggly tires light came on after the car shuddered for about 30 seconds. Now it runs fine but the lights are on. I scheduled a dealer appt for next week but the service advisor said it might have been a loose gas cap (I don't think so, but I re-clicked it shut just in case) and the light might go off. That was 24 hours ago and it's still on.

Any danger driving until next week this way (dealer says no danger)? Any other insight into this problem?

Daryll,
If this is like Toyota, which I assume it is, there could be million things that cause the VSC lights to come on. It could very well be the gas cap, it could also be an O2 sensor, or break ECU, etc. I would stop by the dealer now and have them read the codes while the lights are on. Once they read the codes, they would know what caused the problem. If you want to reset the lights, unplug the battery for 5 minutes or again, stop be the dealer and ask them to reset it.

Good luck,
Dmitry

a loose gas cap will trigger the CEL (check engine light), not the VSC

but yes, the vsc could mean tons of stuff on lexus (just like all previous lexus). best bet is to take it to dealership to figure it out

The lights went off like service said it might! So I guess I'll just ignore the whole thing unless and until they come back on. Maybe it was bad gas or something.

Very odd but I think your approach is correct.