As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT RETURNED TO FIELD WHEN AFTER TAKEOFF THE CREW RECEIVED A RUDDER PRESS CATUION LIGHT. MAINTENANCE INSPECTED THE SYSTEM AND REPLACED THE NR 1 PRESSURE REGULATOR SWITCH. OPERATIONAL CHECKS WERE GOOD AND THE AIRCRAFT WAS RETURNED TO SERVICE.