What was found
FL 370 LEVEL 1 AIR SYS 2 FAIL. AIR SYS AUTO CONTROLLER SHUTDOWN NR 2 AIR SYSTEM 2 MINUTES LATER. LEVEL 3 AIR SYS FAIL FOLLOWED QRH. LAND AT NEAREST SUITABLE EVENTUALLY 10 MINUTES LATER APPROX AIR SYS 2 INDICATED NORMAL. SYSTEM DECAY CHECK PER MD10 AMM 36-00-01-5 AND ALL PARAMETERS WERE WITHIN LIMITS. CHECKED NR 2 PACK BAY, FWD, CTR AND CAC COMPTS FOR LEAKS AND NONE FOUND. REMOVED AND REPLACED MANIFOLD FAILURE DETECTION CONTROLLER AS PRECAUTIONARY PER MD10 AMM 36-23-01-4 AND SYSTEM CHECKS GOOD. RAN NR 2 ENG AT IDLE AND OP`S CHECK THE NR 2 PNEUMATIC SYSTEM AND NO DEFECTS NOTED PER MD10 FDX JRH. OK TO CONTINUE.