[Sergio]

All controllers use the speed sensor to measure the motor rpm.

Starting with the Gray Excel controller there is software that actively monitors and prevents the use of speed magnets, I cannot think of any reason Club Car did that other than protect its profit from selling speed 4 codes.

That is just corporate greed since you already payed for the controller.

Some folks mentioned their White ERIC controllers worked with the speed magnet so maybe Club Car counter measures are not always effective.

Edit: PlumQuick has a "purple bandit" upgrade that circumvents those counter measures by reducing the amount of Regen the motor can produce which is related on how the controller is trying to determine if the motor is actually going faster than the speed sensor indicates.

I personally think the Altrax XCT is a better option than a "purple bandit" motor.