What was found
ACFT DIVERTED WHILE ENROUTE DUE TO A PSEU FAIL MESSAGE ILLUMINATING MULTIPLE TIMES ENROUTE; PARTICULARLY DURING TURBULENCE. PSEU FAIL ILLUMINATED WITH SLAT DOWN ARROW ON APPROACH. THE FLIGHT CREW DECLARED AN EMERGENCY AND DIVERTED BECAUSE THE QRH REQUIRES A ZERO FLAPS LANDING AND A LONGER RUNWAY. THE FAULT EXTINGUISHED ENROUTE AND THE FLIGHT CREW WAS ABLE TO MAKE A NORMAL FLAPS 40 LANDING. TROUBLESHOT IAW FIM 27-80. FOUND RT SLAT SENSOR D1-66 AT FAULT. REPLACED RT SLAT B SENSOR IAW AMM 27-84. PERFORMED GOOD OPS TEST IAW AMM 27-84. THE ACFT HAS RETURNED TO SERVICE.