1999 Lexus LS 400 Owners Manual - Page 331

STARTING AND DRIVING Anti-lock brake system The anti-lock brake system is designed to automatically help prevent lock-up of the wheels during a sudden brake or braking on slippery road surfaces. This assists in providing directional stability and steering performance of the vehicle under these circumstances. The anti-lock brake system becomes operative after the vehicle has accelerated to a speed in excess of approximately 10 km/h (6 mph). It stops operating when the vehicle decelerates to a speed below approximately 5 km/h (3 mph). 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 anti-lock brake system is in the self-check mode, and does not indicate a malfunction. Effective way to press the ABS brake pedal: When the anti-lock brake system function is in action, you may feel the brake pedal pulsating and hear a noise. In this situation, to let the anti-lock brake system work for you, just hold the brake pedal down more firmly. Do not pump the brake in a panic stop. Pumping the brake pedal makes the stopping distance longer. 315