As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT "FWD EQP OVHT " ON EICAS , A/C RETURNED TO THE GATE (BTB) MTX GROUNDED A/C. MTX THEN COOLED MEC WITH EXTERNAL AC UNIT , AND PERFORMED OPERATIONAL CHECK OF EQUIPMENT COOLING PER B 767 AMM 21-58-00. OPS CHECK GOOD. A/C WAS HEAT SOAKED DUE TO HIGH TEMPS IN PHX. MTX RETURNED A/C TO SERVICE .