thermoking sb200 sensor problem

unit shut off to a code 11(alternate sensor) and threw a handful of codes regarding sensors. when turned on the unit will run fine down to setpoint(30F), it cycled off and after a few minutes cycled back on. when it came back on the display showed various temps at random. controller display will say 37F, jump to -127 then jump to 80f and back to 37. after a minute or two the trailer shuts off and code11 pops up.

I replaced the return air temp sensor(left side of the evaporator), the problem persisted so i assumed it was the microprocessor. I checked the connections to the MP, used some electrical cleaner and fresh electrical grease to insulate the wiring plugs going into the board and the problem persisted. I swapped the MP out of another truck and the unit has the still same problem.

i switched the unit from cycle sentry to continuous and let it run to see what it would do and it was able to maintain temp in continuous mode without throwing a code so i left it there. Just wondering if anyone has suggestions, my next course is to check up on more sensors 1 by 1.