03/08/21
Message Overview:
Message Description:
No B-DCU-1 data received at R-IOC.
Possible Causes:
- Data Concentrator Unit (DCU) (A14)
- Right Input/Output Concentrator Unit (A4-IOC2)
- Integrated-Avionics Processor System (IAPS) Card Cage (ICC) (A4)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: 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 |
| Removal of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-000-801 |
| Installation of the Integrated-Avionics Processor System (IAPS) Card Cage (ICC) | AMM 31-45-01-400-801 |
| Removal of the Input/Output Concentrator Unit (IOC) | AMM 31-45-05-000-801 |
| Installation of the Input/Output Concentrator Unit (IOC) | AMM 31-45-05-400-801 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset EICAS DCU B Circuit Breaker CB2-D1 and R IAPS Circuit Breaker CB2-B6. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
NOTE: Before you open the IAPS circuit breakers, make sure that all Engine FADEC circuit breakers are open. If the Engine FADEC circuit breakers remain closed, Engine Igniters will activate. This can cause injury to persons and damage to equipment. - Swap right IOC with left IOC. Is the fault message still present?
- If YES, continue with next step.
- If NO, replace defective IOC.
- Do wiring check between DCU (A14) and the IAPS Card Cage (A4) for the following wires:
From To Result Conn. A14EP1-7A Conn. A4P101-32 Conn. A14EP1-7B Conn. A4P101-33 - If the check is satisfactory, continue with next step.
- If the check is not satisfactory, repair defective wiring.
- Replace DCU (A14). Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Replace IAPS Card Cage (A4).
- Do close out.