What was found
FLIGHT 9010 EN-ROUTE, DURING APPROACH, BLUE BRK LT OR RT FAULT ILLUMINATED WHILE LOWERING THE LG. THE GEAR WAS RETRACTED & THE APPROACH WAS ABANDONED. THE FLIGHT DECLARED AN EMER & DIVERTED FOR A LONGER RUNWAY. WHILE LANDING, THE GEAR WAS AGAIN LOWERED & MSG EXTINGUISHED. THE FLIGHT LANDED WITHOUT FURTHER INCIDENT. MX WAS UNABLE TO DUPLICATE THE FAULT. AS A PRECAUTION, REPLACED THE BCM 1.