03/23/21
Message Overview:
Message Description:
Input from IRS2 to IOC 2X is inactive, and at least 3 of the following; R-IRS-1 input to FGC2 is inactive, R-IRS-2 input to MFD2 is inactive, R-IRS-2 input to PFD2 is inactive and R-IRS-1 input to SPC is inactive.
Possible Causes:
- Inertial Reference Unit (IRU) No. 2 (A232)
- Junction Box (JB4)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Junction Box JB4 | AMM 24-63-13-000-802 |
| Installation of the Junction Box JB4 | AMM 24-63-13-400-802 |
| Removal of the Inertial Reference Unit (IRU) | AMM 34-45-01-000-801 |
| Installation of the Inertial Reference Unit (IRU) | AMM 34-45-01-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Repair Wiring | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset IRS 2 (CB2-C2) circuit breaker.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Confirm 28 VDC and ground returns are available at IRU 2 connector A232P1. Repair/replace as required.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Swap IRUs.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Replace Junction Box 4.
- Do close out.