As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FMC PREFLIGHT SCRATCHPAD MESSAGE "SINGLE FMC OPERATION" APPEARED AND MAP FLAG ON F/O'S ND 0155 ZULU. GROUNDED - YES. PERFORMED FIM 34-61 TASK 801, NO FAULTS NOTED. CYCLED FMC COMPUTER 2 C/B. MAP RESTORED AND "SINGLE FMC OPS" MESSAGE GONE. BITE TEST NORMAL PER FIM TASK 34-61-801.