As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LH ENGINE ANTI-ICE LIGHT AND EICAS MESSAGE ON. CREW ELECTED TO DIVERT TO STL DUE TO KNOWN ICING CONDITIONS AT CVG. AIRCRAFT WAS GROUNDED BY MAINTENANCE. MAINTENANCE ACCOMPLISHED IDLE RUN, DUPLICATED PROBLEM WHEN CYCLING ENGINE ANTI ICE SWITCH. REMOVED AND REPLACED LH ENGINE THERMO ANTI-ICE VAVLE IAW B767 AMM 30-21-03. SYSTEM OPS CHECK GOOD. A/C REMAINS NO ETOPS. AIRCRAFT RETURNED TO SERVICE.