As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT LT AUX PITOT DISCRETE LIGHT AND EICAS AFTER ENGINE START. ACFT RETURNED TO THE GATE AND MTX GROUNDED ACFT. TROUBLESHOT AND REMOVED AND REPLACED LEFT/ CAPTAIN AUX PITOT PROBE IAW AMM 34-11-01 OPS TEST GOOD ACFT REMAINS RVSM COPMPLIANT ACFT REMAINS NO ETOPS.