Update: New battery arrived. It was 86% charged (according to MP charger) so I charged it up slowly to 100%. The old battery was 58% charged, again, according to the MP charger.
Replaced the battery (easy swap) and drove the car around the block. All good for 1mile, parked it overnight.
The following day I went to start it and it turned over for like 10 seconds but wouldn't fire. I removed the key, and tried again. Turned over and fired right off. All good.
Drove another 22 miles and this time the trans fail safe came back. Big time. Car would basically apply the brakes every 50-100ft. Again, all 3 lights (DSC/Brake/ABS) came on. This time however the Brake and ABS light would come on and then shut off, as I was driving. Almost as if a sensor was having an intermittent electrical issue.
In addition the tranny seemed slow to shift/wouldn't up shift. The tranny has plenty of fluid, just checked.
Thoughts?