ABS or Anti-lock Brake System is a mechanism tool that is responsible for the maintainability of vehicle steerability, directional stability, and optimum slowing down on severe braking and on various road surfaces without allowing each wheel fully lock; this is attained by monitoring the rotational speed of each wheel and controlling the brake pressure line. The actuator assembly is found at the right rear corner of the engine compartment While the electric hydraulic pump acts as the main supplier of hydraulic pressure to the brake system during the ABS operation, the solenoids valves for each wheel are used in cases were specific wheel pressure needs to be addressed. Sine wave current is produced from the wheel sensors when the rotors of the sensor turn and the ABS control units convert the analog signal into a digital form to assess the wheel's velocity. The major components of the ABS control unit-which is housed in the actuator-use signals from the wheel speed sensors to modulate hydraulic pressure for the wheel brakes to avoid further lock up while at the same time checking for system failure. At engine start up the ABS light comes on as a normal procedure but should turn off in about one second the self check is done when the vehicle reaches a speed of more than 4mph and at this time a sort of mechanical noise may be heard. If there is an error, the warning light on the dashboard stays on and a code that corresponds to the problem is saved in the control unit.