Transistor Limit Current
A transistor does nothing on its own. However, that is not strictly a transistor. It's an IC with a power transistor and other stuff in it.

Also motors do not drive current, they draw current. But I would say that no matter what you do 1.5A is far too undersized for a motor that can draw up to 20A. And such a motor would not be able to do very much running off 1A anyways even if the transistor doesn't fry.

There are two fundamental kinds of "limiting" as far as current is concerned. The first is to completely interrupt current when it gets too high.

The second is to still allow current to flow but limit the amount of voltage to the load so it doesn't draw too much current. But the extra voltage from the source has to go somewhere and it will appear across the component which will cook it at motor level power currents. This is very similar to how a linear regulator heats up when the input voltage is too high for the output current. Your IC looks like it uses this method which is no good for high power stuff.