I think they do need new hardware. Maybe not
hugely different, but different, for at least two reasons:
- The "bundle of wires" solution hacks the temperature sensor in such a way that it provides inaccurate readings at most temperatures. It should be safe, because the crossover point is where the car is believed to shut down charging if the temperature exceeds that value, but the inaccurate temperature reading could be an issue in other circumstances, or if Tesla decides to change the way its cars respond to temperature in the future.
- As I understand it, cars with the Gen4 hardware include a heating element in the charge port to prevent them from freezing up. Gen3 cars lack this feature, and instead unlock the charge port when charging is finished in cold weather so as to minimize the risk that the charge plug will end up frozen to the car. The "bundle of wires" solution may cause Gen3 cars used in cold weather to be more likely to suffer from frozen charge ports, since the software would try to do the wrong thing in cold weather.
It's possible that these solutions could be overcome in software, but this would require that the software know that a Gen4 was being used with the "bundle of wires." This might be possible to do, especially if Tesla were to install the hardware and therefore could set a flag on affected cars, but a cleaner solution would be to provide a slightly tweaked Gen4 charge port ECU that could properly identify the hardware to the software.
Tesla
could sell the CCS1 adapter with the caveat that it works only with CCS-enabled vehicles. The fact that this would make some people unhappy doesn't prevent this. In fact, people are unhappy that they can't buy the adapter directly from Tesla in North America today.
That said, I think that Tesla may well be delaying introduction of the adapter until they can offer a retrofit for older cars. This is a business decision, though; they may be trying to keep customers happy in one way, but I don't believe their hand is being forced on the issue.