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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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Quick Links

06/20/19

Message Overview:

Fault Message:

APUGCU [WEIGHT ON WHEELS SENSE]

Fault Code:

2420210LPS

Associated CAS:

APU GEN FAIL
(Advisory)

Reporting LRU: Auxiliary Power Unit Generator Control Unit (APU GCU)
System Description: 24-22-00
Schematic Diagram: 24-22-00 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Wiring Diagram: 24-22-01 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Fault Description:

The Auxiliary Power Unit Generator Control Unit (APU GCU) has detected an internal failure related to its Weight On Wheels discrete signal sense circuit and consequently the APU Generator trips off-line. The APU GEN is operating normally. Inhibited during Take-off and Landing.

Possible Causes:

  • Auxiliary Power Unit Generator Control Unit (APU GCU) (A109)

Troubleshooting Tips:

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCU 1, GCU 2, GCU 3, GCU 4 and the APU GCU into a different position (for troubleshooting only). You can monitor the GCU faults in CAIMS via the active faults page.

Quick Links:

Removal of the Generator Control Units (GCU) AMM 24-24-01-000-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Installation of the Generator Control Units (GCU) AMM 24-24-01-400-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]
Access to View Fault Messages AMM 45-47-00-970-801 [ Global Express ]  [ G5000 ]  [ Global XRS ]

Troubleshooting Recommendations:

  1. Do a complete aircraft power reset. Is the fault still present?

    1. If NO, monitor for failure and do close out.
    2. If YES, continue with next step.

    1. Replace APU GCU.
    2. Do close out.

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