As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT THE RIGHT HAND AFT FUEL PIMP INOP MSG APPEARED AFTER ENGINE START A/C RETURNED TO GATE (BTB) AND MTX GROUNDED A/C . MTX FOUND INCORRECT BREAKER WAS LOCKED OUT FOR LH PUMP DEFERRAL . RESET RH BREAKER AND COLLARED CORRECT BREAKER.OPS CHECK GOOD RETURNED A/C TO SERVICE