What was found
WHEN ENGAGED ON CAPTAIN''S SIDE, AUTOPILOT COMMENCES A RIGHT TURN AWAY FROM COMMAND BARS (FLIGHT DIRECTOR). WORKED FINE EN ROUTE HOWEVER, ONCE DESCENT INITIATED AIP WOULD NOT RESPOND TO FLIGHT DIRECTOR. F/O''S SIDE APPEARS TO FUNCTION NORMALLY. DIVERTED FROM ACV TO SFO. REPLACED NUMBER ONE AHRS COMPUTER AND RE-INITIALIZED. AUTOPILOT SYSTEM OP CHECKS GOOD IAW MM 22-11-00. P/N ON: 6226190-204, S/N ON: 967, S/N OFF: 714,