06/20/19
Message Overview:
Fault Message:
APUGCU [PROG PIN 1 SENSE]
Fault Code:
2420216LPS
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:
Auxiliary Power Unit Generator Control Unit (APU GCU) has detected an internal failure related to its pin 1 programming sensing circuit and consequently APU Generator trips off-line. GCU uses 4 programming pins (0, 1, 2 and PAR (parity)) to determine its position (GCU1, GCU2, GCU3, GCU4, APUGCU). The GCU uses the odd parity system to determine if the programming pins are valid.
Possible Causes:
- Auxiliary Power Unit Generator Control Unit (APU GCU) (A109)
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 APU GCU.
NOTE: Use PMAT to monitor the fault on GCU. - Do close out.