03/04/21
Message Overview:
Message Description:
No A-DCU-5 data received at B-DCU and A-RDC.
Possible Causes:
- Data Concentrator Unit (DCU) (A14)
- Remote Data Concentrator (RDC) (A13)
- Junction Box 4 (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 Data Concentrator Unit (DCU) | AMM 31-41-01-000-802 |
| Installation of the Data Concentrator Unit (DCU) | AMM 31-41-01-400-802 |
| Removal of the Remote Data Concentrator (RDC) | AMM 31-41-05-000-802 |
| Installation of the Remote Data Concentrator (RDC) | AMM 31-41-05-400-802 |
| Wiring - Maintenance Practices - ALL | SPM 20-12-00-02 |
| Wire Repair - Maintenance Practices - ALL | SPM 20-12-10-02 |
Troubleshooting Recommendations:
- Reset EICAS DCU A Circuit Breaker CB1-D1, EICAS DCU B Circuit Breaker CB2-D1 and EICAS RDC A Circuit Breaker CB1-D2. Is the fault message still present?
- If NO, do close out.
- If YES, continue with next step.
- Do wiring check between DCU (A14) channel A, DCU (A14) channel B and RDC (A13) channel A, through Junction Box 4, for the following wires:
From To Result Conn A14FP1 - 6A Conn A14EP1 - 6A Conn A14FP1 - 6B Conn A14EP1 - 6B Conn A14FP1 - 6A Conn. A13DP1 - 8A Conn A14FP1 - 6B Conn. A13DP1 - 8B - If the check is satisfactory, continue with next step.
- If the check is not satisfactory, repair wiring or replace defective JB4.
- Replace DCU (A14). Is the fault message still present?
- If YES, continue with next step.
- If NO, do close out.
- Replace RDC (A13).
- Do close out.