As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OU FIRST OFFICER RECEIVED VTK AND MAP WARNINGS ON THE ND CREW RAN THE QRH PROCEDURE AND CONDUCTED REMAINDER OF FLIGHT WITH FMC SOURCE SWITCH IN "BOTH ON L". GROUNDED - YES. DISCREPANCY IS A NUISANCE ERROR PER B737-800 AMM 34-61-00-860-801.