02/16/21
Message Overview:
Message Description:
R-IOC-4 data absent at R-FMC and 1 of [L-FMC, SVC or RIU 1].
Possible Causes:
- Right Input/Output Concentrator Unit (IOC) 2 (A4-IOC)
- Config. Connector (J2000)
- Left Flight Management Computer (FMC) 1 (A4-FMC)
- Right Flight Management Computer (FMC) 2 (A4-FMC)
- Synthetic Vision Computer (SVC) (A230)
- Left Radio Interface Unit (RIU) 1 (A17)
- 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 Radio Interface Unit (RIU) | AMM 23-51-21-000-801 |
| Installation of the Radio Interface Unit (RIU) | AMM 23-51-21-400-801 |
| 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 |
| Removal of the Synthetic Vision Computer (SVC) | AMM 34-34-01-000-801 |
| Installation of the Synthetic Vision Computer (SVC) | AMM 34-34-01-400-801 |
| Removal of the Flight Management Computer (FMC) | AMM 34-61-01-000-801 |
| Installation of the Flight Management Computer (FMC) | AMM 34-61-01-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Wire Repair | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset R IAPS (CB2-B6) circuit breaker.
- If system checks are good, do close out.
- If fault remains, continue with next step.
- Swap IOCs.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Swap FMCs.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Do a wiring check of the ARINC 429 data bus R-IOC-4 from IAPS connector A4P103, through Config Connector J2000, to RIU 1 connector A17P2 and to SVC connector A230AP1. Repair/replace as required.
- If system check passes, do close out.
- If fault remains, continue with next step.
NOTE: An internal short of any LRUs connected to this data bus might cause this failure.
- Replace SVC.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Replace RUI 1.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Replace IAPS Card Cage (ICC).
- Do close out.