2006 Lexus RX 400h Owners Manual - Page 485

STARTING AND DRIVING Brake assist function The brake assist function is designed to assist with emergency braking. When the driver suddenly depresses the brake pedal, the device treats it as emergency braking and adds braking force. If you slam the brakes on or apply the brakes more firmly, more powerful braking will be applied. At this time, you may hear a sound in the engine compartment and feel the vibrations of the brake pedal. This does not indicate a malfunction. Anti−lock brake system function The anti−lock brake system function is designed to help prevent lock−up of the wheels during sudden braking or when braking on slippery road conditions. This assists in providing directional stability and steering performance of the vehicle under these circumstances. 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. This will result in reduced braking performance. Depressing the brake pedal on slippery road surfaces such as on a manhole cover, a steel plate at a construction site, joints in a bridge, etc. on a rainy day tends to activate the anti−lock brake system function. You may hear a click or motor sound in the engine compartment for a few seconds just after the vehicle begins to move. This means that the anti−lock brake system function is in the self−check mode, and does not indicate a malfunction. CAUTION The brake assist function is not designed to shorten braking distance. Always drive at a moderate speed and maintain a safe distance from the vehicle in front of you. Depending on road conditions, braking distance may be longer than that of a vehicle without the brake assist device. If tire chains are used, braking distance may become longer. 449