As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) GROUND CREW REPORTED FLAMES FROM APU EXHAUST DURING PUSHBACK. COCKPIT HAD NO FIRE INDICATIONS. CREW SHUTDOWN AND PASSENGERS DEPLANED. MAINTENANCE INSPECTED AND APU MEL`D. LATER MAINTENANCE TROUBLESHOOTING FOUND APU ECU WITH FAULT/ERROR CODES. APU ECU REPLACED. AIRCRAFT RETURNED TO SERVICE. (TC NR 20070321013)