What was found
GOING THROUGH ABOUT 12,000 FEET AT ABOUT 280 KTS AND ACCELERATING, ECAM MESSAGE OF THRUST REVERSER NR 2 UNLOCKED CAME UP. ENGINE WAS SHUT DOWN AND AIRCRAFT RETURNED TO PHX. REMOVED AND REPLACED NR 2 EEC. CYCLED THRUST REVERSER WITH ENGINE RUNNING SEVERAL TIMES, ALL INDICATIONS NORMAL.