ABS problem unknown to SEAT

Hello everyone, I am going to tell you my case, 4 years ago the Hydraulic Pump of the ABS was changed, the witness was turned on again and I changed the pump in Warranty in Claro Seat, by the way my car is a Seat Toledo 2 1.9 TDI of 110 repro. The fact is that the following year outside warranty the witness was turned on again, AH and the witness was turned on after 20km/h, when the car turned off and turn and do self -diagnosis, the witness went out, but when resuming the march it turns on again, well I made the ABS jump before reaching 20km/Hy the ABS worked, because once on it did not work, and the witness did not work, and the witness did not work. Turning, the fact is that Ace 3 months or so the witness was turned on again to the Seat and they told me that I had to change the control unit, it changed the 700 E, the bomb was 1000, well as I left the ABS and step of 20 I was still turning on, they took me changed the hose the sensor of the ABS the bus Working a few months with that folded, I left the Seat and the witness worked very well, until it turned on again, turned off the car, the next day the same thing happened, when doing self -diagnosis the witness does not turn on but after 20km/h lights, a day it did not turn on and worked very well until it was turned on again, from there it has been on the middle, from there doing all kinds of tests and they have no idea what could be, they say there is 1 case a year like this, then if any if any could hold a hand, thank you very much in advance really thank you