As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB WITH THE RT PACK DEFERRED, THE -L PACK HI PRESS- CAUTION MESSAGE ILLUMINATED. THE CREW DECLARED AN EMERGENCY, RETURNED TO CLT, AND LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE LT PRESSURE REGULATING SHUTOFF VALVE FILTER. THE SYSTEM OPERATIONALLY CHECKED GOOD. THE AIRCRAFT WAS RELEASED FOR SERVICE.