1999 Lexus GS 300 Owners Manual - Page 331

STARTING AND DRIVING 31G023 This light comes on when the ignition key is turned to the "ON" position. After about a few seconds, the light will go off. The light may stay on for about 60 seconds after the engine is started. It is normal if it goes out after a while. Depressing the brake pedal repeatedly may turn on the "ABS" warning light. It is normal if the light goes out after a few seconds. If either of the following conditions occurs, this indicates a malfunction somewhere in the parts monitored by the warning light system. Contact your Lexus dealer as soon as possible to service the vehicle. D The light does not come on as described above, or remains on. D The light comes on while driving. Even if the anti-lock brake system should fail, the brake system will still operate conventionally. But when the "ABS" warning light is on (and the brake system warning light is off), anti-lock brake system is not assisting brake performance so that the wheels could lock up during a sudden brake or braking on slippery road surfaces. Have your vehicle checked by your Lexus dealer as soon as possible. 311