The Electronic Brake Control Module (EBCM) provides the wheel speed sensors with an ignition signal. These sensors deliver a square wave signal to the control module. As the wheel rotates, the sensor produces the signal. This signal is interpreted by the EBCM to determine the speed at which the wheel is rotating.
The wheel speed sensors are hall effect sensors, which have a reluctance wheel. When it moves, it creates interruptions of the magnetic field. This action produces pulses that are provided to the EBCM so that it calculates the speed.
The storage of fault code C0040 OBD2 occurs when the Right Front Wheel Speed Sensor experiences a malfunction in its circuitry. The manufacturer’s determined performance does not match the actual operation.