Not necessarily the sensor itself,not sure on these but I would check and make sure your wheel bearing is ok,ie no play and not noisy,if the pick up isn't in the bearing itself then it will be quite clear if the exciter ring is on the driveshaft itself,if so make sure there is no dirt/breaks in the ring itself. If all is ok then either it is your sensor, sensor to pump wiring fault or a fault in the ECU itself,good luck.
cdc
March 2015