Stupid thought, but did the RJ45s get replaced correctly? Out to IN, repeat until loop is complete? Also when you inject calls, are you getting the lights on car call to light up? This would at least show a good communication. You do not need to spam the TECC function, it's the TECCR that should be spammed, I prefer 5 times but I'm a bit superstitious. TECCR clears the old teach, and allows the system to TECC again, cleanly.