As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF, THE LEFT BLEED VALVE FAILED TO CLOSE WITH THE APU ON AND THE CREW ABORTED TAKEOFF. THE CREW THEN PERFORMED CHECK OF THE SYSTEM WITH THE APU BLEED OFF AND IT OPS CHECKED GOOD. MAINTENANCE THEN DEFERRED THE APU BLEED SYSTEM IN ACCORDANCE WITH 49-1-1C.