The Dealer (non lexus) where I purchased my GS300 had performed the 70K maintenance. When I drove it home the VSC and VSC Off warning lights both came on as did the Engine check light. Took it back to the dealer. Long story short. The timing was off due to an improperly installed timing belt. The car ran smooth but would hesitate bit on acceleration. After they correctly installed the timing belt, the VSC & VSC Off warning lights remain off as does the Check Engine light. The car runs even smoother than before and accelerates without hesitation. I was told that the technician said the water pump had been installed incorrectly causing the timing belt to be set incorrectly. However, I did was not able to speak with the technician myself so this is secondhand information. However, the water pump is part of the 70k maintenance.
