ABS control unit, longitudinal acceleration sensor

Hello! Me again with another problems. I have noticed that my prking sensors do not work all the time, but if I turn ignition off and back on they are working with no problem. Plugged in yesterday, and had the error code 01316- ABS control unit, intermittent fault. Just read about the error code and it says that the wiring, or ABS control unit should be replaced. And there is another problem related to the ABS, when I’m reversing, my rear brakes seems to be stuck, I need to accelerate, in order to reverse for parking. Tonight, when I got home from work, just reversed on my drive, to park the car, the prarking sensor were faulty, and noticed that the brakes not remain stuck, while sensors faulty. Then turned ignition off and back on, sensors were working, but brakes seems to be stuck again...Is the ABS control unit dying, what should I check? If I buy a second hand ABS unit, do I have to recode it? I have to mention that I have no ABS related lights in the dash.

And found another error code( can’t attach the photo, due to 10mb upload limit), which I think it may be related with the one mentioned above:

ABS -With ESP

-01279 -Acceleration sensor, longitudinal, faulty signal, intermittent fault.  Are this two problems connected together? 
Any advices would be much appreciated.

Many thanks