A B767 IN CLB AT 16000 FT DIVERTED DUE TO EICAS FLT CTL WARNINGS WITH AUTOPLT ENGAGE FAILURE AND UNCOMMANDED RUDDER TRIM MOVEMENT. CAUSE OF UNCOMMANDED RUDDER TRIM MOVEMENT UNKNOWN.

Narrative

COPLT; HAND FLYING; TRIMMED ACFT -- ATTEMPTED TO ENGAGE CTR AUTOPLT IN COMMAND MODE. AUTOPLT DISCONNECT LIGHT AND SIREN WARNING; AILERON LOCKOUT EICAS AND RUDDER RATIO EICAS; AND RUDDER TRIM WENT FROM 5 UNITS R TO ZERO UNITS FOR TRIMMED FLT. COPLT FLEW AND TALKED WITH ATC WHILE I RAN THE PROCS; TALKED WITH DISPATCH AND MAINT; FLT ATTENDANTS AND PAX. WE TRIED TO DETERMINE THE EXTENT OF ANY PROBS TALKING WITH MAINT. WE WERE NOT ABLE TO ENGAGE ANY AUTOPLT OR CLR THE EICAS CAUTIONS. AN UNEVENTFUL LNDG WAS MADE AT ZZZ. MAINT WAS ABLE TO FIX THE AILERON AND RUDDER RATIO PROBS; BUT COULD NOT EXPLAIN THE ABRUPT CHANGE IN RUDDER TRIM AND THE FLT WAS CANCELED. COPLT STATED HE WAS ENGAGING THE AUTOPLT AND PROCEEDED TO PUSH THE CTR AUTOPLT COMMAND SWITCH. WHEN HE PUSHED THE SWITCH; THE AUTOPLT DISCONNECT WARNING AND SIREN SOUNDED; RUDDER RATIO LIGHT AND EICAS; AND THE AILERON LOCKOUT LIGHT AND EICAS. THE ACFT AT THIS POINT REQUIRED APPROX 30 DEGS OF L AILERON TO MAINTAIN STRAIGHT FLT. I ADVISED ATC THAT WE HAD A PROB AND WOULD LEVEL AT 17000 FT. HE ASKED WHAT THE NATURE OF THE PROB WS AND I STATED I WOULD GET BACK TO HIM IN A SHORT TIME.