What was found
LEFT FMC APPEARED TO FAIL FOR 3-4 MINUTES THEN RESET. OBS INDICATIONS REPEATED 3 TIMES, LAST ONE PUT FMC SW TO FMC "R", VTK ON LEFT ND, NO FMC DATA ON LEFT ND, BOTH MCDU'S HAD NO FMC PROMPT, RIGHT ND NORMAL. GROUNDED - YES. ACCOMPLISHED FMC BITE, BITE SHOWS FMC-L- PGM FAULT. REF B737-900 FIM 34-61 TASK 801. PER REF FIM 34-61 TASK 807 DO NOT REPLACE FMC FOR THIS FAULT. ACCOMP FMC SENSOR STATUS TEST FOR BOTH FMC'S ALL OK. ACCOMP FIX OUTPUT TEST, TEST PASSES FOR BOTH FMC'S REF B737-900 AMM 34-61-00-710-026.