02/16/21
Message Overview:
Message Name:
NO PSEU-B BUS INPUT
Message Code:
B3-224026
Associated CAS:
| Reporting LRU: | IOC 2 |
| System Description: | 22-00-00 |
| Schematic Diagram: | None |
| Wiring Diagram: | None |
Message Description:
PSEU-B data absent at R-IOC and not absent at DCU-B/A.
Possible Causes:
- Right Input/Output Concentrator Unit (IOC) (A4-IOC)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Fault Confirmation Procedure:
- Message# = 20
- Comp Id = A004
- Fault Logged = AIR,TAXI
- Status = FAILED/WIRING
- {Term Definitions}
- IC2IN-1 2X 352 01 EXCT XXXX-TXXX XXXX-XXXX XXXX-XXXX 352: 28; WD1 PSEU-B INPUT FAIL
- DCU2-32 2X 357 10 EXCT XXXX-TXXX XXXX-XXXX XXXX-XXXX 357: 28; PSEU-B BUS INOP
- DCU1-32 1X 357 01 EXCT XXXX-TXXX XXXX-XXXX XXXX-XXXX 357: 28; PSEU-B BUS INOP
Quick Links:
| Operational Test of the Integrated-Avionics Processor System (IAPS) | AMM 31-45-00-710-801 |
| 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 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
| Electrical Connectors - Maintenance Practice - ALL | SPM 20-20-00-02 |
Troubleshooting Recommendations:
- Suspect wiring or failed L-IOC input.
- Reset L IAPS Circuit Breaker CB2-B6. Is the fault message still present?
- If YES, continue with next step.
- If NO, do close out.
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.
- Replace Integrated Avionics-Processor System (IAPS) Card Cage (ICC) (A4).
- Do close out.