2003 Lexus LS 430 Owners Manual - Page 297

STARTING AND DRIVING 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 when the ignition switch is turned to the "ON" position, or remains on. D The light comes on while you are driving. A warning light turning on briefly during operation does not indicate a problem. Brake assist system If you slam the brakes on such as in an emergency or apply the brakes more firmly than usual such as when descending the hill with the designated number of occupants in the vehicle, the brake assist system provides more powerful braking. 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. The brake assist 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). For an explanation of this system's warning light, see "ABS" warning light on page 51 or 282. CAUTION If the "ABS" warning light remains on together with the brake system warning light, immediately stop your vehicle at a safe place and contact your Lexus dealer. In this case, not only the anti−lock brake system will fail but also the vehicle will become extremely unstable during braking. Drum−in−disc type parking brake system Your vehicle has a drum−in−disc type parking brake system. This type of brake system needs bedding−down of the brake shoes periodically or whenever the parking brake shoes and/or drums are replaced. Have your Lexus dealer perform the bedding−down. 283