As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT FMC VTK FLAG APPEARED. LOST LEFT FMC SWITCHED TO RT FMC ONLY FOR NORMAL OPS. AFTER 1 MINUTE PLACED FMC SWITCH BACK TO NORMAL. OPS NORMAL FOR REMAINDER OF FLIGHT. GROUNDED - YES. PERFORMED B737-900 FIM 34-61 TASK 836 & NO FAULTS FOUND. GROUND FUNCTIONAL CK GOOD.