06/20/19
Message Overview:
Fault Message:
APUGCU [OPEN CCT TR2/TR3 F1]
Fault Code:
2420166LPS
Associated CAS:
| 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:
Open circuit on Transistor (TR2)/TR3 detected on internal monitoring channel F1.
Possible Causes:
- Auxiliary Power Unit (APU) Generator Control Unit (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 ] |
Troubleshooting Recommendations:
- Remove power from the A/C completely. Apply power to the A/C. Is the fault still present?
- If YES, continue with next step.
- If NO, monitor for failure and do close out.
- Replace APU GCU.
- Do close out.