As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT C HYD PRIMARY 1 EICAS MESSAGE APPEARED , AC RETURNED TO GATE (BTB) AND MTX GROUNDED AC . TROUBLESHOT, AND REMOVED AND REPLACED ELECTRICAL LOAD CONTROL UNIT IAW B767 AMM 29-11-14 OPS CHECK OK AT THIS TIME . AND RETURNED AC TO SERVICE .