As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - FLIGHT 2188 - RECEIVED A MISTRIM NOSE UP AND TRIM NOSE DOWN MESSAGE WHEN LEVELING OFF FROM CLIMB AND DESCENT. RAN CHECKLIST AND DE SELECTED AUTOPILOT. TRIM FORCE WAS OPPOSITE OF MESSAGE, AND MESSAGE WENT AWAY. MAINTENANCE PLACED THE SYSTEM ON MEL 22-1. AIRCRAFT RETURNED TO SERVICE.