As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTS MAINT LIGHT ON. GROUNDED - YES. INTERROGATED OMF, FOUND MAINT MESSAGE 21-65151 FOR CONT CAB TRIM VALVE SIGNAL OUT OF RANGE OR NOT IN COMMANDED POSITION. PERFORMED OPS TEST PER B737-9 IFIM 21-61-00-810-840. MAINT MESSAGE CLEARED.