03/31/21
Message Overview:
Message Description:
TSS-TA/RA-1 data bus is reported inactive by the left MFD and left PFD.
Possible Causes:
- Traffic Alert and Collision-Avoidance System (TCAS) Transceiver (TSS-4100) (A238)
- Adaptive Flight-Display Unit (PFD) 1 (A27)
- Adaptive Flight-Display Unit (MFD) 1 (A29)
- Junction Box (JB3)
- Associated Wiring
Troubleshooting Tips:
Advisory Wire/Service Bulletin: None
Forum Articles/Infoservice/Newsletter: None
Quick Links:
| Removal of the Junction Box JB3 | AMM 24-63-09-000-802 |
| Installation of the Junction Box JB3 | AMM 24-63-09-400-802 |
| Removal of the Adaptive Flight-Display Unit | AMM 31-61-01-000-801 |
| Installation of the Adaptive Flight-Display Unit | AMM 31-61-01-400-801 |
| Removal of the Traffic/Collision Avoidance System (TCAS) and Traffic Surveillance System (TSS) Transponder Unit | AMM 34-43-03-000-801 |
| Installation of the Traffic/Collision Avoidance System (TCAS) and Traffic Surveillance System (TSS) Transponder Unit | AMM 34-43-03-400-801 |
| Standard Practices - Replace Wiring | SPM 20-12-00-02 |
| Standard Practices - Repair Wiring | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset TCAS/XPDR 1 Circuit Breaker CB1-A5. Is the fault message still present?
- If YES, continue with next step.
- If NO, do close out.
- Swap the Left PFD (A27) with the Right PFD (A26). Is the fault message present?
- If YES, continue with next step.
- If NO, replace defective PFD.
- Swap the Left MFD (A29) with the Right MFD (A28). Is the fault message present?
- If YES, continue with next step.
- If NO, replace defective PFD.
- Do wiring check between Left PFD (A27), Left MFD (A29) and Traffic/Collision Avoidance System (TCAS) and Traffic Surveillance System (TSS) Transponder Unit (A238), through the Junction Box No. 3 (JB3) for the following wires:
From To Results A27P2 - 84 A238BP1 - E1 A27P2 - 85 A238BP1 - F1 A29P2 - 84 A238BP1 - E1 A29P2 - 85 A238BP1 - F1 - If wiring check is satisfactory, continue with next step.
- If wiring check is not satisfactory, repair the defective wire or the Junction Box No. 3.
- Replace Traffic/Collision Avoidance System (TCAS) and Traffic Surveillance System (TSS) Transponder Unit (A238).
- Do close out.