I assume it would work being the same Aisin solenoid used in the A42DL and A43DLFrom Volvo forums - The hack to fix a broken OD solenoid (or broken control circuit) is to dremel grind a small groove between the center hole and slot on the bottom of the OD solenoid, and reinstall to allow fluid to move and disable the solenoid such that it acts like its always powered. You're left with a 4-speed automatic transmission - (OD) gear works normally, and you can dispense completely with all the other components (relay, shifter switch, wiring, etc.). Nothing left to fail. You merely lose the ability to manually downshift into third gear.
(A42DL): Use a Dremel 1/8 inch grinding tool (the metal is hard so you will use two) or a diamond bit. Clean the matching holes in the tranny using drill bits the same diameter, but don't drop them into the transmission. Replace the outer O-ring but not the inner where the groove passes through.
What? Really? My A43DE 3 speed auto with OD will shift 4 times with this mod?you're left with a 4-speed automatic transmission - (OD) gear works normally