DOC AIRBUS | TSM A320FFailure of the 1553 Data Bus between the GAPCU and the GCU 1 and GCU 2
TASK 24-22-00-810-831-A
Failure of the 1553 Data Bus between the GAPCU and the GCU 1 and GCU 2
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 24-22-00-740-079-A ** ON A/C NOT FOR ALL
Subtask 24-22-00-810-090-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:26:38 UTC
Failure of the 1553 Data Bus between the GAPCU and the GCU 1 and GCU 2
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 24-22-34-000-001 | Removal of the GCU-1(2) |
| AMM 24-22-34-400-001 | Installation of the GCU-1(2) |
| ASM 242302 | |
| AMM 24-41-00-740-002 | Operational Check of the GAPCU via the CFDS |
| AMM 24-41-34-000-001 | Removal of the Ground Power Control Unit (GPCU) |
| AMM 24-41-34-400-001 | Installation of the Ground Power Control Unit (GPCU) |
Subtask 24-22-00-740-079-A ** ON A/C NOT FOR ALL
A. Test
(1) On the ELEC panel 35VU, do a check of the position of the BUS TIE pushbutton switch (10XU) when the CFDS message PB SW BUS TIE (10XU)/ GAPCU (24XG) comes into view.
(a) If the BUS TIE pushbutton switch (10XU) is released:
4. Fault Isolation(1) On the ELEC panel 35VU, do a check of the position of the BUS TIE pushbutton switch (10XU) when the CFDS message PB SW BUS TIE (10XU)/ GAPCU (24XG) comes into view.
(a) If the BUS TIE pushbutton switch (10XU) is released:
- stop the trouble shooting.
- do the BITE test of the GAPCU AMM 24-41-00-740-002.
- do the trouble shooting given in Para 4.A.
- do the trouble shooting given in Para 4.B.
Subtask 24-22-00-810-090-A ** ON A/C NOT FOR ALL
A. If the BITE test gives the message TEST FAILED:
Subtask 24-22-00-810-091-A ** ON A/C NOT FOR ALL - push the line key adjacent to the TEST FAILED message.
- replace the GAPCU [24XG] AMM 24-41-34-000-001 and AMM 24-41-34-400-001.
B. If the BITE test gives the message TEST PASSED:
Subtask 24-22-00-740-080-A ** ON A/C NOT FOR ALL - do a check of the wiring of the 1553 data bus ASM 242302 for an open circuit, a short to ground, a short to shield or a short circuit between:
. pin A/6J of the GCU 1 and pin A/11E of the GAPCU
. pin A/6H of the GCU 1 and pin A/12E of the GAPCU
. pin A/6J of the GCU 2 and pin A/11F of the GAPCU
. pin A/6H of the GCU 2 and pin A/12F of the GAPCU.
- repair or replace as necessary.
- replace the GCU-1 [1XU1] and the GCU-2 [1XU2] AMM 24-22-34-000-001 and AMM 24-22-34-400-001.
C. Do the test given in Para. 3.