The ability for the Nissan ABS Wheel Speed Sensor to know if the wheel is turning during the brake procedure is how this anti locking system works. There is an individual ABS wheel speed sensor for each wheel that is mounted on your Nissan. It is connected to the ABS system by a wire so the data from the reading the sensor is making can be retrieved.
The ABS wheel speed sensor is negatively affected by road debris and passing of time as all electronic devices are. If either of these cause the ABS wheel speed sensor to fail in sending a signal to the ABS system or the on board computer, the ABS light on the dashboard will become illuminated. This will be the first indication to the driver that a wheel could lock up if the brakes are applied in slippery road conditions.
The very first thing a Nissan owner should do is to visually inspect each of the sensors measuring the rotation of the wheels. One of the items to look for is if the Nissan ABS wheel speed sensor is covered with dirt or mud that could have been picked up from the road. Another common reason for the sensor to become faulty is if the wire leading to it has become disconnected or cut for some reason.
If neither of these situations is present then the problem more than likely is the ABS wheel speed sensor itself has failed and is in need of replacement. Once the problem is repaired on your Nissan, the ABS light on the dashboard will no longer light up and it is safe once again to drive your vehicle in any weather condition.