DPAK FET (with logiclevel gatedrive). Either for other applications... or ... There are places (since genboard v3.2) for max 2 (often called extraFETs) at the bottom of the board, on Econoseal-18 / pin6 and pin12 (otherwise normally used for extra analog inputs instead).
Can be used to control lightbulb, boostcontrol or idle-air solenoid or other load (but external flyback diode is needed for inductive load). This is different (DPAK, or TO252) footprint than the main TO220 switches (10 FETs + 8 IGBTs), does not require clamping to case - but recommended max current is 3..6A (vs. the 10..14A of a case-cooled TO-220 FET).

Model: IRLR024N or HUF76423-D3S
Rds < 0.03 to 0.06 Ohm according to datasheet, measured value is often as low as 0.01 Ohm.