P0502 low voltage 2001 Oldsmobile Bravada

Yes, P0410, which I have been working on since last inspection. Had it fixed and it returned within 1 week.
ABS codes: B0223/226/236/237/265.
Also forgot to include the fact that I have replaced my alternator due to low voltage.
Having done all this, I have not had the codes cleared either by disconnecting the battery or having a friend with a diag meter clear the codes.

By test harness do you mean the VSS connection and cable? Could this one issue lead to the others?

Update: I got so frustrated, that I took it into the local dealership. $300 later, I find that it has 3 VSS, all the same part number but different locations. The dealer replaced the failing one and charged me the labor. None of the Autozone pics showed three. The dealer parts guy showed me the same pic but did not show me the location of the other two.I would really like to see a pic/diagram of the exact locations. For the $300, I could have bought all brand new VSS and replaced them my self and still had money to take my wife out to dinner. Live and learn! Hey, all the dash lights are out and it shifts normally.

Sorry, forgot, yes, the speedometer and odmeter are working as well!

I had this code and I ordered the speed sensor from rockauto parts, it arrived I replaced the part and the check engine light came back on, I called and asked if they could send me a replacement, yes they replied if its faulty, Well it doesn't work I replied, did you put it on the vehicle already I was asked. Yes I did, Then unfortunately we cannot give you a refund or replacement they stated! Ok so it doesn't work but because I put it on my vehicle you wont refund my money.