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

07/14/23

Message Overview:

Message Name:

NO FQGC OUTPUT TO RDC

Message Code:

B3-006788

Associated CAS:

FUEL QUANTITY FAIL
(Caution)

Reporting LRU: FQGC
System Description: 28-41-00
Schematic Diagram: 28-41-00
Wiring Diagram: 28-41-01

Message Description:

FQGC output bus data is invalid or missing to channel 'A' and 'B' RDC.

Possible Causes:

  • Fuel Quantity Gauging Computer (FQGC) (A57)
  • Remote Data Concentrator (RDC) (A13)
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin:

Forum Articles/Infoservice/Newsletter: None

Quick Links:

Built-In Test of the Fuel-Quantity Gauging System AMM 28-41-00-740-801
Removal of the Fuel Quantity Computer AMM 28-41-01-000-801
Installation of the Fuel Quantity Computer AMM 28-41-01-400-801
Removal of the Remote Data Concentrator (RDC) AMM 31-41-05-000-802
Installation of the Remote Data Concentrator (RDC) AMM 31-41-05-400-802
Wiring - Maintenance Practices - ALL SPM 20-12-00-02
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02
Electrical Connectors - Maintenance Practice - ALL SPM 20-20-00-02

Troubleshooting Recommendations:

  1. Make sure Refuel/Defuel panel is set to OFF and reset the following circuit breakers, waiting 10 seconds before pushing the breakers back:

    Circuit Breaker Name
    CB3-C3 FUEL QTY 1
    CB4-C3 FUEL QTY 2
    CB1-D2 EICAS RDC A
    CB2-D2 EICAS RDC B

    1. If the amber 'FUEL QTY FAIL' EICAS message is still displayed, go to next step.
    2. If the amber 'FUEL QTY FAIL' EICAS message is no longer displayed, do close out.

  2. Verify fuel synoptic page for any MAGENTA parameters other than fuel quantities.

    1. If any abnormal MAGENTA indications other than fuel quantities are displayed on the Fuel Synoptic page, or were reported displayed by pilots at a time that can be correlated to B3-006788, replace RDC.
    2. If there are no abnormal MAGENTA parameters, go to next step.

  3. Re-rack the Fuel Quantity Gauging Computer (FQGC). Is the fault message still present?

    1. If YES, go to next step.
    2. If NO, do close out.

  4. Carry out wiring checks per Table below. Repair or replace any defective wiring as required.

    Connector Pin + Connector Pin - Expected Result
    A13EP1 A1 A57BP1 79 Continuity
    A13EP1 B1 A57BP1 78 Continuity
    A13DP1 A1 A57BP1 67 Continuity
    A13DP1 B1 A57BP1 68 Continuity

  5. Do power checks per table below. Repair or replace any defective wiring as required.

    Connector Pin (28 VDC) Pin (Ground) Expected Result
    A57BP1 95 97 ≈28 VDC
    A57BP1 105 103 ≈28 VDC

  6. If wiring is found serviceable, replace FQGC.
  7. If fault continues, replace RDC.
  8. Do close out.

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