Dc or pwm for aio 3pin connector

So my aio pump cable only had a 3 pin connector and when connected left 1 pin on the mobo where the pump connector is supposed to go.Would that make it dc? My mobo had it set to pwm , should i leave it to pwm or change it to dc? By default everything in my system is reversed my 4pin connector which im assuming are the pwm are set to dc but my aio is set to pwn, or maybe im wrong idk lmao