What is the function of wheel speed sensors?

The function of wheel speed sensors is primarily to provide the vehicle's electronic control system with real-time data regarding the rotational speed of each wheel. This information is vital for various systems, particularly for anti-lock braking systems (ABS) and traction control systems (TCS). By monitoring these speeds, the control module can determine if a wheel is about to lock up during braking or if it is spinning faster than the others during acceleration.

In the context of the choices provided, the option stating that the wheel speed sensors send an A/C signal to the control module correctly highlights that they transmit data that can be used for adjusting braking dynamics and improving vehicle safety. The sensors contribute to preventing skidding and maintaining control during various driving conditions.

The other options pertain to functions that wheel speed sensors do not perform. For instance, while brake pad wear can be monitored through different types of sensors, it is not the primary role of wheel speed sensors. Similarly, adjusting brake fluid pressure is managed by other components in the braking system, and tire pressure levels are tracked by dedicated tire pressure monitoring systems, not by wheel speed sensors. Thus, identifying the purpose of wheel speed sensors as transmitting data to the control module underscores their integral role in vehicle dynamics and safety systems.