Hacking a Corsair Commander Pro
A pump is undefined for the load current. But for a beefy driver use a low RdsOn logic level FET.
The SMD code for Y2 could be the PNP transistor SS8550 so a Pch would be compatible and for 2A and worst-case power dissipation of 200mW from I^2Ron=Pd.  Choose smaller Ron ($) or external FET for bigger currents with a suitable heatsink.  Chose Imax rating 10x what you need to achieve low Ron.