1997 Nissan Pathfinder Owner's Manual - Page 140

ANTI-LOCK BRAKE SYSTEM slope or long grade, reduce speed and downshift to a lower gear. The anti-lock brake system controls the brakes at each wheel so the wheels will not lock when braking abruptly 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 wheel lockup, the system helps the driver maintain steering control and helps to minimize swerving and spinning on slippery surfaces. very quickly). While the actuator is working, you may feel a pulsation in the brake pedal and hear a noise or vibration from the actuator under the hood. This is normal and indicates that the anti-lock system is working properly. However, the pulsation may indicate that road conditions are hazardous and extra care is required while driving. If a tire slips on rough roads for more than 10 seconds, the ABS brake warning light may come on. Turn OFF the ignition key, restart the engine and drive the vehicle at speeds above 20 MPH (30 km/h). If the warning light does not go out, have the vehicle checked at a NISSAN dealer. While driving on a slippery surface, be careful when braking, accelerating or downshifting. Abrupt braking or accelerating could cause the wheels to skid and result in an accident. Using the system Depress the brake pedal and hold it down. Do not pump the brake pedal. Doing so may result in increased stopping distances. Self-test feature The anti-lock brake system consists of electronic sensors, electric pumps, and hydraulic solenoids controlled by 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 is not an indication of any malfunction. If the computer senses any malfunction, it switches the antilock brake system OFF and turns on the "ABS" brake warning light in the dashboard. The Normal operation The anti-lock brake system will not operate at speeds below 3 to 6 MPH (5 to 10 km/h) to completely stop the vehicle. (The speeds will vary according to road conditions.) When the anti-lock system senses that one or more wheels are close to locking up, the actuator (under the hood) rapidly applies and releases hydraulic pressure (like pumping the brakes 4-25