Three sources for HP pneumatic air?
ENG BLEED FAULT
overpressure
overheat
wing or engine leak
valve NOT closed during engine start
valve NOT closed with APU bleed on
X-BLEED in AUTO
open if APU bleed valve is open
closed if APU bleed valve is closed
closed if wing, pylon or APU leak
APU BLEED FAULT
Bleed leak
BMC
Bleed Monitoring Computer