As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI RT ENG BLEED OFF AND RT PACK OFF EICAS MESSAGE APPEARED A/C RETURNED TO GATE(BTB) AND MTX GROUNDED ACFT AND FOUND PRVC SENSE LINE LOOSE, RESECURED LINE OPS CHECK GOOD IAW AMM 36-11-19 A/C REMAINS ETOPS 180 RETURNED A/C TO SERVICE .