What was found
WHILE CLIMBING FROM FL340 TO FL360 BOTH CAPTAIN & CO-PILOT, HAD VTK FLAGS ON MAP DISPLAY. ROUTED DROPPED OUT OF FMC AND AUTO PILOT WENT INTO CONTROL WHEEL STEER PITCH AND ROLL SEVERAL SECONDS LATER CHECKED POS REF PG 2 IN FMC AS WELL AS POS SHIFT PAGE 3 AND ALL INDICATION NORMAL. WE RE-INPUT ROUTE IN FMC AND ENGAGED LNAV AND VNAV WITH NO FURTHER FAILURES. GROUNDED - YES. PERFORMED FMC SYS RESET PER B737-900 FIM 34-61 TASK 836 ETOPS GRND VERIFICATION NORMAL.