background
x
loader
Troubleshooting
arrow By ATA By Message Color By Observed Faults by MDCBy Tips

Select color for CAS message that you wish to troubleshoot

(WARNING)
RED MESSAGE (CAUTION)
AMBER MESSAGE (ADVISORY)
CYAN MESSAGE (STATUS)
WHITE MESSAGE Require immediate crew attention. These messages are accompanied by flashing master warning, triple chime attenson with or without voice message or dedicated tone. Require immediate crew awareness and future crew action may be required in the form of alternate system selection or performance limitation. These message are accompanied by flashing master caution and a single chime. Indicate safe or normal system operation which require crew awareness, over and above the dark cockpit philosophy. Indicate minor failures or reduction in systems capability, which require no crew action.

This page includes :

For AOG assistance contact:

CRC Montreal (YUL)
Quick Links

02/25/21

Message Overview:

Message Name:

SHORT CIRCUIT

Message Code:

B3-008131

Associated CAS:

FIRE SYS FAULT
(Advisory)

Reporting LRU: APU FIRE LOOP A
System Description: 26-13-00
Schematic Diagram: 26-13-00
Wiring Diagram: 26-13-01

Message Description:

Short circuit on APU element A103 or A104, wire short, or FIREX Control Unit internal failure.

Possible Causes:

  • APU Fire Detection Loop
  • FIREX Control Unit (A91)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Quick Links:

Removal of the Fire-Detection-and-Extinguishing (FIREX) Control-Unit AMM 26-11-01-000-801
Installation of the Fire-Detection-and-Extinguishing (FIREX) Control-Unit AMM 26-11-01-400-801
Removal of the Eductor Sensing Element AMM 26-13-01-000-801
Installation of the Eductor Sensing Element AMM 26-13-01-400-801
Removal of the Firewall Sensing Element AMM 26-13-05-000-801
Installation of the Firewall Sensing Element AMM 26-13-05-400-801
Kiddie Aerospace CMM 26-11-88
Electrical Bonding - Adjustment/Test SPM 51-80-00-05
Wiring - Maintenance Practices - ALL SPM 20-12-00-02
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02

Troubleshooting Recommendations:

  1. Reset FIREX Control Unit (A91) circuit breakers CB1-A11 and CB5-A3. Check MDC for fault.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  2. Do LDE Checks of the APU Fire Loop A. Repair/replace as required.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  3. Inspect the suspected fire loops for proper installation and adjust as required.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  4. Perform the electrical bonding test.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

  5. Replace FIREX control unit.
  6. Do close out.
    apu_fire_loopfirex_block

Registered and/or unregistered trademarks of Bombardier Inc. or its subsidiaries. © 2015 Bombardier Inc. All rights reserved.