What was found
ABORTED TAKEOFF - FLT 0299 - DURING TAKEOFF ROLL AT MIA EN ROUTE TO PHX THE CREW ABORTED TAKEOFF DUE TO AN INERTIAL REFERENCE (NR 2 IR) FAULT AT 90 KTS. AIRCRAFT TAXIED BACK TO GATE AND MEL 34-10-01 COND. 4, "NR 2 IR INOP" WAS ISSUED. ON 07/14/2003 MAINT R & R THE NR 2 AIR DATA INERTIAL REFERENCE UNIT (ADIRU) IAW T/C R2A34304, AUTO LAND TEST WAS GOOD PER T/C A1B22307. VENDORS BENCH TEST OF ADIRU S/N 1531 COULD NOT VERIFY REASON FOR REMOVAL. PERFORMED THERMAL CALIBRATION OF UNIT, UNIT TESTED IAW CMM TP1011, REV. 22.