Jazz Aviation-LP CRJ-900-Brake Overheat Indication

C-FIJZ, a Jazz Aviation LP CRJ-900 was conducting flight AC8624 from Toronto/Lester B. Pearson Intl. (CYYZ), ON to Ronald Reagan Washington National (KDCA), DC. During initial approach and prior to landing gear extension, flight crew received a brake overheat warning indication from righthand outboard brake. Flight crew requested emergency services to be present upon landing. Fire department inspected the brakes prior to taxi in to terminal and found no indication of brake overheat.
Maintenance found faulty sensor was the cause of indication.