Had the same problem a few years back and it was caused by the passengers side front wheel sensor. From memory the resistance between the two wires read O.K. as yours do but the earth shield is not at earth potential and was shorting to earth through a chaffed outer insulator. At the ABS module connector check the resistance between the earth shield side of the cable and actual vehicle earth and see if one reads different to the other 3. Just a thought. Actually have the same problem again now but haven't looked into it yet.