So I finally got my Icarsoft to diagnose the issue.
I have TC and HDC lights on, NOT the ABS, and yes the light bulb works.
My codes are:
no battery supply voltage
sticking throttle detected
shuttle valve switch electrical failure
engine speed input signal intermittant/missing

So I cleared those out and TC and HDC are back and working (tested) and currently no issue. Granted it was a 2 minute test drive.
So I assume to wait and see what comes back. Anyone have any thoughts offhand as to the culprit? The grounding bypass was already done and worked a couple years.

Also talked to Disco Mike for a good while, thanks for all the help Mike!

 

it is possible when the option #2 rework was done they did not replace the seals just the shuttle valve switch and the brake fluid is attacking the switch again

 

Sounds like an electrical problem. I had some similar codes once and it was corrosion in the computers. The SLABS module and the ECM talk to each other and SLABS provides road speed to the ECM and ECM provides TPS, RPM, etc to the SLABS.

Can the icarsoft give you live data from the different computers? If so, you might try to compare what data the ECM sees vs what the SLABS sees.

 

IT is possible the PO only did the wiring.
How did you address the corroded computers? Thankfully I'm not in the rust belt, so hopefully that's not it

 

I'm not in the rust belt either. For me it was water leaks. Either sunroof or maybe even windshield.

I was able to open them up and scrub the circuit boards and connectors with dish soap and a tooth brush under running water in the kitchen sink.

No warranty and if you decide to do that do it at your own risk.