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

03/16/21

Message Overview:

Message Name:

IB BCU INTERFACE FAIL

Message Code:

B3-224420

Associated CAS:

BRAKE FAULT
(Advisory)

Reporting LRU: BRAKE CTRL UNIT
System Description: 32-43-00
Schematic Diagram: 32-43-00
Wiring Diagram: 32-43-01

Message Description:

The BCU has detected a discrepancy with one or more discrete input from the PSEU. This code can result from a fault with the PSEU or a component of the PSEU system.

Possible Causes:

  • Weight-On-Wheel (WOW) System 2 Sensor
  • Gear Handle Sensor
  • Uplock Sensor
  • Proximity-Sensor Electronic Unit (PSEU) (A9)
  • Brake Control Unit (BCU) (A67)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Quick Links:

Removal of the Brake Control Unit AMM 32-43-01-000-801
Installation of the Brake Control Unit AMM 32-43-01-400-801
Removal of the Proximity-Sensor Electronic Unit (PSEU) AMM 32-61-09-000-801
Installation of the Proximity-Sensor Electronic Unit (PSEU) AMM 32-61-09-400-801
Data Download from the Maintenance Diagnostic Computer (MDC) AMM 45-45-01-970-802
Standard Practices - Replace Wiring SPM 20-12-00-02
Standard Practices - Electrical Wiring-Continuity Test - Adjustment/Test SPM 20-12-01-05
Standard Practices - Wire Repair SPM 20-12-10-02

Troubleshooting Recommendations:

  1. Address any 'PROX SYS FAULT', 'WOW FAIL' or 'GEAR DISAGREE' CAS message first.
  2. If no 'PROX SYS FAULT', 'WOW FAIL' or 'GEAR DISAGREE' message are associated with this code, do the following:

    1. Do a wiring check per the following table:

      From (PSEU) Pin To (BCU) Pin
      A9CP1 8C A67P2 14
      A9CP1 8D A67P2 84
      A9CP1 7A A67P2 81
      A9CP1 5A A67P2 82

    2. If wiring is found serviceable, replace BCU.
    3. If fault continues, replace PSEU.

  3. Do close out.

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