As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INITIAL REPORT - DURING CLIMB, THE RIGHT ENVIR FAIL LIGHT CAME ON, CREW RETURNED TO STATION WITH NO FURTHER INCIDENT. INITIALLY DEFERRED PER MEL 21-4. THE PRECOOLER BYPASS VALVE AND THE PRESSURE REGULATOR VALVE WERE REMOVED AND REPLACED. SYSTEM OPERATIONALLY CHECKED GOOD.