2003 Lexus GS 430 User Guide - Page 214

You may hear a sound in the engine compartment for a few seconds when the engine is started or just after the vehicle is started. This means that the vehicle skid control is in the self-check mode and does not indicate a malfunction. Vehicle skid control system failure warning 31G015-1 31G021b These lights warn when there is a problem somewhere in the vehicle skid control system or traction control system. You can turn off the vehicle skid control system by pushing the "VSC OFF" switch. The "VSC OFF" indicator comes on. At this time, the traction control system also turns off. You cannot turn off either one of them. Pushing the "VSC OFF" switch a second time turns the system back on and extinguishes the "VSC OFF" indicator light. When you turn the ignition switch on, this system always turns on. If the "VSC" warning light and "VSC OFF" indicator light come on, have your vehicle checked by Lexus dealer as soon as possible. The lights will come on when the ignition key is turned to "ON", and will go off after about a few seconds. The lights may stay on for 60 seconds after the ignition key is turned to the "ON" position. It is normal if they go out after a while. Depressing the brake pedal repeatedly may turn on the lights. It is normal if they go out after a few seconds. If the "VSC" warning light and "VSC OFF" indicator light come on, the vehicle skid control system does not activate, however, it is no problem to continue your driving.