Front wheel sensors are inside the hub and unless the hub is bad , it is not likely the sensor needs to be cleaned.
Lots can happen in a year. Corrosion and condensation never stops. Have an open mind and work through the steps. Never assume anything is good until you inspect it.
Jamming on the brakes is not going to bleed the module. That can only be done with bleeding and a tool to activate the abs module. For the owner lacking the Tech2, your best bet is bleeding and hope the module is good.
Bleeding the brakes not only changes the fluid and removes the air. It can also serve to center the proportioning valve. If you have a stuck caliper or leak in the system, this valve serves to isolate that failed part and retain braking. Centering it is "resetting" it.
"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving! - ThunderII KE7CSK