FUEL SHUT-OFF VALVE CLOSED ADVISORY LIGHT (white)

• APU fuel shut-off valve closed
• APU shutdown, manually or automatically

FUEL SHUT-OFF VALVE OPEN ADVISORY LIGHT (green)

• APU fuel shut-off valve open
• PWR switch light pushed
• APU circuits armed for starting or fire test

FIRE ADVISORY LIGHT (red)

• APU fire detected
• after 7 seconds extinguishing agent automatically releases, and the amber BTL ARM light goes out

EXTG SWITCH LIGHT (guarded, alternate action)

EXTG segment (white)

• APU fire extinguisher bottle can be activated manually if BTL ARM light is on

PUSH - EXTG segment (out)

• APU fire bottle cannot be activated or has been set off

BOTTLE LOW LIGHT (amber)

• fire extinguisher bottle is low or empty

FAULT ADVISORY LIGHT (amber)

• fault in the APU fire extinguisher system
• fault in the APU FPP