ABS activates when braking on dry pavement

This is my girl friends car. She told me the brakes are grinding. Checked the brake pads and the front brakes looked kind of thin and the rear pads were over half worn. Replaced all the pads and put new rotors on too. Told her okay you are good to go. She came home the next day and said the brakes are still grinding. I did not test drive it. Looked on line and found there was a lot of problems with the brake boosters on these vehicles. So I ordered a new one and put it on. Then I drove it. (I should have drove it from the beginning). Well I discovered that almost every time I stepped on the brake the ABS activated and gave me a pulsing pedal. Then I went to the scanner and found I had a problem in the l/f. I replaced both sensors in the front. Drove it and it still gave me an ABS pedal. No ABS light came on. I checked all the wiring from the ABS module and out to the sensors.I found no rubbed wires I did not ohm out all the wires. So I checked the wheel bearings and abs sensors. So I replaced the ABS module/valve body/motor assembly. That did not fix it. My last resort is to replace the ECM which includes the anti yaw and ABS processing information. My girl friend thinks this is a lot of money and wants to know if it will fix it?