What was found
AT CRUISE ELEVATOR FEEL MASTER CAUTION, AUTOPILOT DISENGAGED, AHRS2 FAILED. DIVERTED, LANDING UNEVENTFUL. REMOVED FROM SERVICE. INTERROGATED CDS, FOUND 'NO DATA FROM AHRS2' MESSAGE. REMOVED AND REPLACED #2 AHRS IAW MTC 6342101. C/W OPS TEST OF ELEVATOR CONTROL SYSTEM PER Q400 FIM 27-30-00-810-802. ELEVATOR FEEL LIGHT REMAINS EXTINGUISHED. DETERMINED AUTOPILOT DISENGAGE DUE TO FAILURE OF AHRS #2. AHRS 2 LLM RTS IAW MTC 6342101. AIRCRAFT REMAINS CAT III QUALIFIED. COCKPIT PLACARD READS CAT III. RETURNED TO SERVICE.