What was found
AIRCRAFT PERFORMED AN UNSCHEDULED LANDING AT GDL AS CONSEQUENCE OF AUTOPILOT WAS OUT OF SERVICE. LEFT PFD INDICATOR WAS REPLACED IAW MM 34-24-00; TESTS WERE PERFORMED IN STP, SHOWING FAILURE CODE A/P HEART BEAT TEST FAILURE AND AIL/MECH TORQ SWITCH FAILURE. BOTH DFGC WERE REPLACED; TESTS WERE PERFORMED SHOWING FAILURE CODE PITCH TRIM 440 AND A/P FAILURE CODE 440 AND 312. COMPUTERS CONTROL PANEL WAS REPLACED IAW MM 22-01-04; AUTO TEST RTS WAS PERFORMED SHOWING FAILURE CODE PITCH TRIM 440 IN BOTH COMPUTERS. THE R20-14 WAS REPLACED AND TESTS WERE PERFORMED IAW MM 22-01-05, ALL CORRECT.