The Anti Lock Brake (ABS) and Vehicle Stability Assist (VSA) systems are also built to enhance vehicle steerability, directional stability and the best possible deceleration, all under severe braking on any of the road surfaces. The ABS watches for wheel lockup during heavy braking controlling brake line pressure according to wheel rotational speed and the VSA aids in correcting over/under steering. The Traction Control System (TCS) enables vehicle control in difficult situations together with, but the Traction Control System (TCS) prevents wheel spin during acceleration on slippery roads, and so on. An electric hydraulic pump is in the engine compartment in the modulator unit with the modulator unit containing solenoid valves to modulate brake line pressure and the actuating hydraulics which are the electric hydraulic pump to the actuating hydraulics to provide pressure to the braking system. An electronic module interprets a signal produced by each of a pair of speed sensors that generate a signal proportional to wheel speed. Steering knuckle and the rear suspension knuckle mounting the front sensors and rear sensors respectively. On the modulator, the ABSNSA computer processes sensor information so that hydraulic pressure can be controlled, and that system faults are monitored. If a dashboard warning light stays illuminated, then verify the brake fluid level, secure electrical connections, and the fuses, but especially check fuses, before having a professional diagnose and repair your vehicle. Before handling electrical connections you should turn off the ignition with caution. To remove the wheel speed sensor the vehicle will need to be raised and supported securely, the ignition turned off and the sensor wiring traced and disconnected before removing the sensor from the knuckle. Following this installation is done in reverse order and all components are secure.