What was found
(AIRCRAFT GROUNDED) (EMERGENCY DECLARED) WHEEL N/W STRG FAULT ON ECAM IN AIR. / RESET BSCU 1 & 2 AND BITE CHECK NO FAULTS IAW AMM 32-46-00-740-001A. OPS CHECK OF NSW STILL INOP. ALL HYD SYSTEMS QTY NORMAL, NO SIGN OF LEAKS. TROUBLESHOT PER TSM 32-51-00-810-818-A. GVI OF FDBK SENSORS 3GC AND 4GC NORMAL. REMOVED AND REPLACED BSCU AND OPS CHECKS GOOD IAW A320 AMM 32-42-400-001-A, 32-46-00-740--001-A AND 32-51-00-720-003-A."