in the red circle is the power stage. it handles the high amperage current for both the injectors and the ignition. ie there are two circuits inside.

the two screws holding the power stage down are securing it to an aluminum heatsink. between the power stage and the heatsink, there is supposed to be a layer of dielectric grease: to help conduct the heat away from the power transistors inside. if, and when this grease dries up and disappears, the power stage will overheat...and fail. sometimes, just one side craps out. for example, the ignition side transistor got too hot and failed: no spark. but the other side for the fuel injectors may still be working. or vice versa. or both sides can fail.

preventive maintenance: remove the power stage from its heatsink and make sure there is adequate dielectric grease in between the 'stage and the heatsink.

this pic is of a power stage in a 740; but in a 240 it is also mounted in the left front [driver's side] inner fender area.