As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT PACK TEMP EICAS MESSAGE DURING DESCENT, FOLLOWED QRH. PERFORMED BITE TEST OF THE PACK TEMP CONTROLLER IAW FIM 21-51 FT 803. FOUND TEMP CONTROL VALVE ON TEMP CONTROLLER. REMOVED AND REPLACED THE RT PACK TEMP CONTROL VALVE IAW AMM 21-51-12. OPS AND LEAK CHECKED GOOD.