As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT TAI 425, THE PILOT REPORTED AMS CTRL FAIL MSG ON EICAS AT FL370. THEREFORE, THE FLIGHT WAS DIVERTED TO ITS ALTERNATE AIRPORT. NO OWL WAS REPORTED. REPLACED THE AMS CONTROLLER CHA 1 & CHA 2 IAW FIM 21-00-00-810-805-A & AMM 21-00-01-000 400-801-A. PRESSURIZATION TEST WAS PERFORMED WITH NO FAILURE MSGS. ONCE THE DESCRIBED MX ACTIONS WERE COMPLETED, THE ACFT WAS RETURNED TO SERVICE.