As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW REPORTED TCAS FAILED INFLIGHT FLAGGED FOR SDR REF FIM 34-45 TASK 801 BITE TEST OF TCAS FOUND HDNG FAULT. REMOVED AND REPLACED ADIRU 1 IAW AMM 34-21-01. ADIRU OPS CHECKED GOOD. TCAS OPS CHECKED GOOD IAW AMM 34-45-02-700-801-C2. PERFORMED LAND VERIFY TEST IAW AMM 22-11-00, CAT STATUS RESTORED TO FULL CAPABILITY.