What was found
ANTISKID OUTBOARD BECAME INOPERATIVE ON DESCENT INTO MSN. THE FLIGHT DIVERTED TO ORD. THEY DECLARED AN EMERGENCY, DID NOT BRACE, AND DID NOT LAND OVERWEIGHT. ANTI/SKID OUTBOARD CAUTION MSG IN FLIGHT / DEFERRED ANTI-SKID SYSTEM OUTBOARD CHANNEL PER MEL 32-44-01-2 CAT B. C/W M FUNCTION BY PERFORMING OPS CHECK OF BRAKE SYSTEM IAW CRJ 900 AMM 32-43-00-710-801. INTERROGATED MDC AND FOUND NO CURRENT FAULTS, MDC HISTORY HAD B1 CODES 006057, 006058, & 007479. REMOVED & VISUALLY INSPECTED R/H O/B MLG WHEEL SPEED TRANSDUCER AND ASSOCIATED WIRING AND REINSTALLED IAW CRJ 900 AMM 32-44-01-000/400-801. PERFORMED CONTINUITY CHECK OF ASCU A165P1 PIN 51 TO 50 NO OPEN CIRCUIT. REMOVED AND REPLACED ASCU IAW CRJ 900 AMM 32-44-06-000/400-801 OP CHECK AND BITE CHECK GOOD THIS CLEARS MEL