06/25/19
Message Overview:
Fault Message:
GCU1 [INTERNAL 10V REFERENCE]
Fault Code:
2421097LPS
Associated CAS:
| Reporting LRU: | Generator Control Unit (GCU) 1 |
| System Description: | 24-21-00 |
| Schematic Diagram: | 24-21-00 [ Global Express ] [ G5000 ] [ Global XRS ] |
| Wiring Diagram: | 24-21-01 [ Global Express ] [ G5000 ] [ Global XRS ] |
Fault Description:
Generator Control Unit (GCU) 1 has detected an internal 10 volt reference fault, consequently resulting in a Generator 1 to tripped off-line or not come on-line. The GCU Generator Control Switch (GCS) sensing circuit has detected the OFF signal as being the same as the ON signal.
Possible Causes:
- Generator Control Unit (GCU) 1 (A56)
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
The GCU NVMs can only be downloaded at position #2 or #3.
A GCU patch cable (GSE REF # 24X-24-02) can be used to swap GCU 1, GCU4 and APU GCU into position 2 or 3 (for troubleshooting only).
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 GCU 1. NOTE: Use PMAT to monitor the fault on GCU.
- Do close out.