06/14/19
Message Overview:
Fault Message:
APUGCU [OPEN CIRCUIT TR4]
Fault Code:
2420106LPS
Associated CAS:
| Reporting LRU: | Auxiliary Power Unit (APU) Generator Control Unit (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 (APU) Generator Control Unit (GCU) has detected a failure (open circuit) associated with Transistor 4 (TR4), consequently resulting in APU Generator to tripped off-line or not come on-line.
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 GCUs 1, 4 and 5 into position 2 or 3 (for troubleshooting only).
The GCU NVMs can only be downloaded at position #2 or #3.
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:
- Replace APU GCU.
NOTE: Use PMAT to monitor the fault on GCU. - Do close out.