03/05/25
Message Overview:
Message Name:
NO IASC1-A BUS INPUT
Message Code:
B3-006505
| Reporting LRU: | Data Concentrator Unit (DCU) Channel A |
| Associated CAS: | None |
| System Description: | 31-41-00 - Engine Indication and Crew Alerting System (EICAS) |
| Schematic Diagram: | SSM 31-41-00-101 - Engine Indication and Crew Alerting System (EICAS) |
| Wiring Diagram: | WM 21-31-03-1_001 - Sheet 1 - Integrated Air System Controller (IASC) Interface - ALL WM 31-41-01-1_001 - Sheet 1 - Data Concentrator Unit (inserts A - C) - ALL WM 31-41-02-1_001 - Sheet 1 - Data Concentrator Unit (inserts D - F) - ALL WM 31-41-03-1_001 - Sheet 1 - Data Concentrator Unit (Interface) - [20501 TO 20886, 20888 TO 20890, 20896 TO 20898] WM 31-41-13-1_001 - Sheet 1 - EICAS (Power and Indication) - ALL |
Message Description:
No IASC1-A bus input to Data Concentrator Unit (DCU) Channel A but data is present at DCU Channel B.
Possible Causes:
- Data Concentrator Unit (DCU) (A14)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Full Throttle Blog/Forum Articles/Infoservice/Newsletter: None
Flight Operation Notifications Manual (FONM): None
Quick Links:
| Removal of the Data Concentrator Unit (DCU) | AMM 31-41-01-000-802 |
| Installation of the Data Concentrator Unit (DCU) | AMM 31-41-01-400-802 |
| Safety Precautions - Maintenance Practices - ALL | SPM 20-00-01-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Reset EICAS DCU A Circuit Breaker CB1-D1. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Replace DCU (A14).
- Do close out.