As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE RIGHT HAND HIGH PRESSURE BLEED VALVE WOULD NOT CLOSE, DURING TAXI FOR TAKEOFF. THE AIRCRAFT RETURNED TO THE GATE. MAINTENANCE INSPECTED AND FOUND THE HIGH PRESSURE BLEED VALVE CANNON PLUG TO BE LOOSE. MAINTENANCE SECURED AND FUNCTION CHECKED THE RIGHT HAND HIGH PRESSURE BLEED VALVE IN ACCORDANCE WITH DORNIER MAINTENANCE MANUAL 36-11-07.