FIREX APU SQUIB FAIL
(Caution)

Indicates the APU fire extinguisher squib on bottle #2 has failed with no low pressure indication.

• Fire-Detection-and-Extinguishing (FIREX) Control Unit (A91)
• Fire Extinguishing Container 2, APU Discharge Cartridge (A115)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Interrogate the MDC as follows:

   1. On the cursor control panel, ensure the toggle switch is to the right and select Anti-Ice, ECS and Fuel buttons simultaneously. The MDC main menu should now be displayed on Display Unit #3.
   2. Using the joystick, select Current Faults (if the fault is active) or Aircraft History to research stored faults. From Aircraft History you can then select Fault Message History and locate the Firex system. Going into advanced diagnostics will provide an equation id for the fault identified.
   3. Select the MDC fault or equation from the drop down below to provide additional information to assist in troubleshooting.
      Select an MDC Fault Code/Message:B3-006747 - INTERNAL FAULT [FIREX CTRL UNIT]B3-008128 - BOTH BRIDGEWIRES OPEN [APU SQUIB]