Without more information as I mentioned in my comment, it's hard to be specific, but in general it appears there's a fair chance one of your wheel speed sensors is having issues. Either a sensor has failed, a tone ring has come loose, or perhaps there is damage to the wiring. Being located on the wheels, those sensors are exposed to harsh elements on the road and are susceptible to damage.
Have you scanned the OBD-II port for any diagnostic trouble codes? Those should point you in the right direction to help diagnose the issue. I don't know where in the world you're located, but here in the US most auto parts stores will scan your engine computer for free. Once you have the code(s), come on back and edit your question to add that information.