My truck has had a new speedsensor and trans speed sensor. The abs light is still on and my scanner is shooting code PO720 for the trans. I reset that and it is not coming on now. but the ABS shoots the 72 ECU ROM checksum error... what is that. I tested the speedsensor on the rear end and it is a 1602 ohms. which is normal. but at the ABS controller it is 1593 ohms.. What should i do. run new wires??? Please help