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(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.

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07/17/19

Message Overview:

Fault Message:

DEFUEL SOV ELECT PWR/WRG

Fault Code:

2844639PK

Associated CAS:

AFT RD VALVE OPEN
(Advisory)

L RD VALVE OPEN
(Advisory)

R RD VALVE OPEN
(Advisory)

Reporting LRU: Fuel Management and Quantity Gauging Computer (FMQGC)
System Description: 28-23-00
Schematic Diagram: 28-23-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 28-23-03 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Fault Description:

DEFUEL VALVES LMS/WRG FAULT shows when the conditions that follow occur:

  • The Left Defuel Shut-off Valve is commanded to close
  • The open feedback-signal for the Left Defuel SOV is true or the close feedback signal is false
  • There is an Electrical Management System (EMS)/Auxiliary Power Unit (APU) Start Contactor Assembly (ASCA) failure

OR,

  • The Left Defuel SOV is commanded to open
  • The open feedback-signal for the Left Defuel SOV is false or the close feedback-signal is true
  • There is an Electrical Management System (EMS)/APU Start Contactor Assembly (ASCA) failure

Possible Causes:

  • Fuel Management and Quantity Gauging Computer (FMQGC) (A47)
  • Aft Refuel Shut-off Valve (L4)
  • Auxiliary Power Unit (APU) Start Contactor Assembly (ASCA) (A48)
  • Junction Box (JB6)
  • Junction Box (JB6)/PCB1
  • Junction Box (JB6)/PCB2
  • Junction Box (JB6)/PCB3
  • Auxiliary Power Unit (APU) Main Battery
  • Associated Wiring

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

Quick Links:

Removal of the Junction Box JB6 AMM 24-00-13-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Junction Box JB6 AMM 24-00-13-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Junction Box JB6 Circuit-Cards AMM 24-00-14-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Junction Box JB6 Circuit-Cards AMM 24-00-14-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Aft Refuel Shutoff-Valve AMM 28-23-33-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Aft Refuel Shutoff-Valve AMM 28-23-33-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Removal of the Computer AMM 28-41-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Computer AMM 28-41-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wire Repair - Maintenance Practices - ALL SPM 20-12-10-02 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  1. Disconnect the Aft Refuel/Defuel SOV connector L4P1. Perform the following:

    1. Apply power to the aircraft.
    2. Set the MASTER switch on the REFUEL/DEFUEL control panel to 'ON'.
    3. Set the REFUEL/AUTO REFUEL DEFUEL switch to 'REFUEL'.
    4. Set the MANUAL/AFT switch to 'CLOSE'.

  2. On Aft R/D SOV connector L4P1, perform a voltage and ground check as follows:

    From To Expected Result Result
    L4P1-B Ground 28 ±2 VDC
    L4P1-A Ground Continuity

    1. If all checks are good, go to step 5.
    2. If there is no continuity on L4P1-A, repair defective wiring as required and do close out.
    3. If there is no voltage on L4P1-B, continue with next step.

  3. Access JB6 test points. Perform a voltage and ground check as follows:

    From To Expected Result Result
    JB6 PCB1 TP-95 aircraft 9002 to 9119 Ground 28 ±2 VDC
    JB6 PCB1 TP-92 aircraft 9120 to 9158 Ground 28 ±2 VDC
    JB6 PCB1 TP-19 Ground Open

    1. If there is continuity on TP-19, investigate wiring and go to step 7.
    2. If there no voltage on TP-95 or TP-92, use System Schematic 28-23-00 to investigate the power source.
    3. If all checks are good, continue with next step.

  4. Perform a voltage check as follows:

    From To Expected Result Result
    JB6 PCB2 TP-36 aircraft 9002 to 9119 Ground 28 ±2 VDC
    JB6 PCB2 TP-35 aircraft 9120 to 9158 Ground 28 ±2 VDC
    JB6 PCB3 TP-37 aircraft 9002 to 9119 Ground 28 ±2 VDC
    JB6 PCB3 TP-36 aircraft 9120 to 9158 Ground 28 ±2 VDC

    1. If all checks are good, investigate wiring between the Aft R/D SOV and JB6.
    2. If PCB3 has no voltage, replace PCB3 and do close out.
    3. If only PCB2 has no voltage, replace PCB2 and do close out.

  5. Set the MANUAL/AFT switch to 'OPEN'. On Aft R/D SOV connector L4P1, perform a voltage check as follows:

    From To Expected Result Result
    L4P1-D Ground 28 ±2 VDC

    1. If there is voltage, replace the Aft R/D SOV and do close out.
    2. If there is no voltage, continue with next step.

  6. Access JB6 test points. Perform a voltage and ground check as follows:

    From To Expected Result Result
    JB6 PCB1 TP-95 aircraft 9002 to 9119 Ground 28 ±2 VDC
    JB6 PCB1 TP-92 aircraft 9120 to 9158 Ground 28 ±2 VDC
    JB6 PCB1 TP-19 Ground Continuity

    1. If all checks are good, replace JB6 PCB1 and do close out.
    2. If there no voltage on TP-95 or TP-92, use System Schematic 28-23-00 to investigate the power source.
    3. If there is no continuity on TP-19, investigate wiring and continue with next step.

  7. Replace the FMQGC.
  8. Do close out.

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