As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT RECEIVED STAB TRIM AND MACH TRIM CAUTION MESSAGES. ALSO RECEIVED AP PITCH TRIM CAUTION MSG. DISCONNECTED AP. C/W QRH. MESSAGES REMAINED. AIR RETURN TO DAY. LANDED UNDER 47000 LBS. ***AIRCRAFT REMOVED FROM SERVICE **** R&R CA PITCH TRIM DISCONNECT SWITCH IAW AMM 27-41-30. THIS AND AP BOTH OPS CHECK GOOD.