Spartan 3 Termite Serial communication

I just purchased two Spartan 3’s and cant get communication via termite. I saw a couple of posts here about confirming the heater ground is good on pin 4 and a YouTube video stating add LF at the end of the serial commands… still cant communicate. Is there a workaround or a firmware version for this? I need to set the CANID’s so Tuner Studio will know which sensor is which.