I will be out there tomorrow and will post what i have found, thanks for the help

well when it was flashing a 4,3 that is a thermal cutback code
replacing the tpa board was a final solution if code did not clear

as for the 2,1 code this is a throttle wiper input fault
corrective actions:
step1- set vom to dc volts, pos lead on JPT11-5, neg lead on JPT11-6
full speed request = 4.25v, no travel request 0 volts.
If it passes test replace STM
step2- set vom to dc volts, pos lead on J1-6, neg lead on J1-7
Full speed request = approx. 4.25v, No travel request = 0v.
if passes replace TPA, if fails troubleshoot wires from STM.

check your connections and wiring first, then run the above test to see of this STM is bad or just connected incorrectly.

Ok im not crazy then lol. Yeah its a 261 the bdi will flash 21 was a 43 before the card was replaced i believe, and the board on the tractor side (above steering card) shows a 21 and i cant seem to find anything either....

is this unit actually a 261 series unit? or is it an EASI unit?
i looked in my series 261 service book and it only speaks of flash codes and monitoring the led on the traction amp for blink codes.
anyway code 21 on an easi unit is a transistor fault.