Dreaded ABS+Brake+DSC issue

[Lawaia]

I'm in dire need of some assistance. Several weeks ago the 3 lights came on and since have not extinguished on my '01 4.4. The peake code reads 78 (Vehicle Speed). So after a bit of research I came to the conclusion that it had to be one of the front ABS sensors because both speedo and cruise control works without issue. So I ordered one and installed on both front left and right but lights will not go out. I cleared the codes and drove at least 5 miles but no luck; code 78 reappears. What are the chances that one of the rear ABS sensors is bad? Is there anything else I can try to fix this problem?
Any info would be greatly appreciated.
Thanks.