I have slept too many times since dealing with that system, but it seems likely.  My problem was code 4, "voltage input is too high".  It turned out that my tractor harness had a bad internal wiring splice which caused the alternator to overcharge the battery and my system was wired directly to the battery.  My dealer wanted the Trimble system wired directly from the battery to be sure that it had sufficient voltage all the time.  It is probably worth your time to wire a volt meter directly to the wire that your Trimble system is powered from to see if the voltage to the Trimble system drops when you pull the steering wheel against the steering motor (which would likely cause the steering motor to pull more power, resulting in lower voltage if you have a power supply issue), thus triggering the low voltage code.