2014 Nissan Sentra Owner's Manual - Page 288

- When installing a spare tire, make sure that it is the proper size and type as specified on the Tire and Loading Information label. See "Technical and consumer information" section of this manual. - For detailed information, see "Wheels and tires" in the "Maintenance and do-it-yourself" section of this manual. The Anti-lock Braking System (ABS) controls the brakes so the wheels do not lock during hard braking or when braking on slippery surfaces. The system detects the rotation speed at each wheel and varies the brake fluid pressure to prevent each wheel from locking and sliding. By preventing each wheel from locking, the system helps the driver maintain steering control and helps to minimize swerving and spinning on slippery surfaces. WARNING Do not pump the brake pedal. Doing so may result in increased stopping distances. Self-test feature The ABS includes electronic sensors, electric pumps, hydraulic solenoids and a computer. The computer has a built-in diagnostic feature that tests the system each time you start the engine and move the vehicle at a low speed in forward or reverse. When the self-test occurs, you may hear a "clunk" noise and/or feel a pulsation in the brake pedal. This is normal and does not indicate a malfunction. If the computer senses a malfunction, it switches the ABS off and illuminates the ABS warning light on the instrument panel. The brake system then operates normally, but without anti-lock assistance. If the ABS warning light illuminates during the self-test or while driving, have the vehicle checked by a NISSAN dealer. When the ABS senses that 1 or more wheels are close to locking up, the actuator rapidly applies and releases hydraulic pressure. This action is similar to pumping the brakes very quickly. You may feel a pulsation in the brake pedal and hear a noise from under the hood or feel a vibration from the actuator when it is operating. This is normal and indicates that the ABS is operating properly. However, the pulsation may indicate that road conditions are hazardous and extra care is required while driving. Using the system Depress the brake pedal and hold it down. Depress the brake pedal with firm steady pressure, but do not pump the brakes. The ABS will operate to prevent the wheels from locking up. Steer the vehicle to avoid obstacles. Normal operation The ABS operates at speeds above 3 - 6 MPH (5 - 10 km/h). The speed varies according to road conditions. Starting and driving 5-31