What was found
AIRCRAFT WAS GROUNDED: FLIGHT RETURNED TO ORD ON ACCOUNT OF AUTO PILOT TRIM FAULTED. AN EMERGENCY WAS DECLARED AND THE FLIGHT LANDED OVERWEIGHT WITHOUT INCIDENT. MAINTENANCE REPORTS DFCS BITE SHOWS FAULT - A/P DISC CHAN-A VNAV SPD LNAV ENG - RAN LRU TEST. HAD FAULT SPEED/STAB CHAN-A ELEV POS SEN-1. MAINTENANCE REPLACED ELEV POS SEN M929 IAW AMM 22-11-30-400-801, NO HELP. MAINTENANCE REMOVED A/P ELEVATOR ACTUATOR SYS A IAW AMM 22-11-26. ACCOMPLISHED AUTOPILOT ELEVATOR ACTUATOR ADJUSTMENT AND TEST IAW AMM 22-11-26-820-801. ALL INDICATION NORMAL, OK FOR SERVICE.