The wheel speed sensor also has an input to the ECU for engine idle control. There is a plug near the RH wheel hub in the sensor loom and that seems to be the source of many of these problems, a look and clean of that would be a good starting place. There are a number of Google instructions for checking the function of the wheel speed sensor by spinning the wheel and checking the resistance at the plug on RH hub. Better to check the sensor than just replace it. If you had a new sensor 3 years ago you would hope that it is not the problem. Clean and remaking all the plug connections is a worth a try.
