What are the two main components of the wheel speed sensors in ABS?

The correct response identifies the two main components of the wheel speed sensors in an Anti-lock Braking System (ABS) as the exciter and the pickup.

The exciter, often a toothed ring, is typically mounted on the wheel hub. As the wheels rotate, this exciter generates a changing magnetic field. The pickup, usually a Hall effect or variable reluctance sensor, detects the changes in this magnetic field. The information gathered by the pickup about the rotation speed of the wheel is then transmitted to the ABS control module, allowing for real-time monitoring and modulation of brake pressure to prevent wheel lock-up during braking.

The relationship between the exciter and the pickup is crucial for the functioning of the ABS system. The exciter provides the physical input necessary for the sensor to measure, and without these two components working together, the ABS cannot function effectively to enhance vehicle stability and control during braking.