04/02/21
Message Overview:
Message Description:
R-GP-5 bus data absent at TAWS and NOT A-DCU or B-DCU; TAWS not in test.
Possible Causes:
- Terrain-Avoidance Warning System (TAWS) Computer (A34)
- 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 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Repair Wiring | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset TAWS (CB2-A6) circuit breaker or push in the TAWS TEST/RESET switch on the center pedestal.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Do the wiring check of the ARINC 429 data bus R-GP-5 from the TAWS computer connector A34AP1, through the Junction Box 4, to the DCU connector A14EP1. Repair/replace as required.
- If system check passes, do close out.
- If fault remains, continue with next step.
- Replace the TAWS computer.
- Do close out.