As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - ON PUSHBACK FOR FLIGHT 4277 RECEIVED A -L FADEC FAULT 2- STATUS MESSAGE AND ENGINE WOULD NOT START. RETURNED, FOUND APU LOAD CONTROL VALVE CLOSED, NOT ENOUGH AIR FOR START. RECONFIGURED VALVES, ENGINE STARTED MESSAGE CLEARED. RETURNED TO SERVICE. NO PARTS REPLACED.