DOC AIRBUS | TSM A320FLoss of the DLRB Signal to the ATSU
TASK 31-38-00-810-812-A
Loss of the DLRB Signal to the ATSU
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 31-38-00-710-065-A ** ON A/C NOT FOR ALL
Subtask 31-38-00-810-061-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:30:08 UTC
Loss of the DLRB Signal to the ATSU
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| ASM 313801 | |
| AMM 31-38-34-000-001 | Removal of the Data Loading Routing Box (DLRB) |
| AMM 31-38-34-400-001 | Installation of the Data Loading Routing Box (DLRB) |
Subtask 31-38-00-710-065-A ** ON A/C NOT FOR ALL
A. Do the loading of the correct data base of the ATSU (Ref. AMM 46-21-00, P. Block 301).
4. Fault IsolationSubtask 31-38-00-810-061-A ** ON A/C NOT FOR ALL
A. If the fault is identified by the crew observation:
ATSU uploading is not possible.
(1) Do a check of the aircraft wiring between the MDDU [1TD] and ATSU [1TX1] ASM 313801:
(a) Pin A/24, 25 (1TD) to pin AA/8J, 8K (1TX1).
(b) Pin A/31, 32 (1TD) to pin AA/1A, 1B (1TX1).
(2) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and ATSU [1TX1] ASM 313801:
Subtask 31-38-00-810-061-B ** ON A/C NOT FOR ALL ATSU uploading is not possible.
(1) Do a check of the aircraft wiring between the MDDU [1TD] and ATSU [1TX1] ASM 313801:
(a) Pin A/24, 25 (1TD) to pin AA/8J, 8K (1TX1).
(b) Pin A/31, 32 (1TD) to pin AA/1A, 1B (1TX1).
(2) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and ATSU [1TX1] ASM 313801:
- Pin A/11 (102TD) to pin AA/14F (1TX1).
- Replace the ROUTING BOX-DATA LOADING [102TD] AMM 31-38-34-000-001 and AMM 31-38-34-400-001.
A. If the fault is identified by the crew observation:
ATSU uploading is not possible.
(1) Do a check of the aircraft wiring between the connector (2TD) and ATSU [1TX1] ASM 313801:
(a) Pin A/24, 25 (2TD) to pin AA/8J, 8K (1TX1).
(b) Pin A/31, 32 (2TD) to pin AA/1A, 1B (1TX1).
(2) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and ATSU [1TX1] ASM 313801:
Subtask 31-38-00-710-066-A ** ON A/C NOT FOR ALL ATSU uploading is not possible.
(1) Do a check of the aircraft wiring between the connector (2TD) and ATSU [1TX1] ASM 313801:
(a) Pin A/24, 25 (2TD) to pin AA/8J, 8K (1TX1).
(b) Pin A/31, 32 (2TD) to pin AA/1A, 1B (1TX1).
(2) Do a check of the aircraft wiring between the ROUTING BOX-DATA LOADING [102TD] and ATSU [1TX1] ASM 313801:
- Pin A/11 (102TD) to pin AA/14F (1TX1).
- Pin B/2 (102TD) to pin A/19 (2TD).
- Replace the ROUTING BOX-DATA LOADING [102TD] AMM 31-38-34-000-001 and AMM 31-38-34-400-001.
B. Do the test given in Para. 3.A.