DOC AIRBUS | TSM A320FSLT FPPU or Wiring Fault
TASK 27-81-00-810-806-A
SLT FPPU or Wiring Fault
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 27-81-00-740-050-A
Subtask 27-81-00-810-055-A
Subtask 27-81-00-942-055-A
[Rev.8 from Aug 2018]
2026.04.04 04:27:47 UTC
SLT FPPU or Wiring Fault
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 27-51-34-000-001 | Removal of the SFCC |
| AMM 27-51-34-400-001 | Installation of the SFCC |
| AMM 27-81-00-740-002 | BITE Test of the Slat and Flap Control Computers (Slat System) |
| ASM 278106 | |
| ASM 278107 | |
| AMM 27-81-19-000-001 | Removal of the Feed Back Position Pick-Off Unit |
| AMM 27-81-19-400-001 | Installation of the Feed Back Position Pick-Off Unit |
| AMM 27-84-00-710-001 | Operational Test of the Slat System |
Subtask 27-81-00-740-050-A
A. Test
(1) Do a BITE test on the SFCC 1 (2) AMM 27-81-00-740-002.
(a) If the message SLT FPPU 28CV OR WIRING TO SFCC is shown, do the fault isolation.
4. Fault Isolation(1) Do a BITE test on the SFCC 1 (2) AMM 27-81-00-740-002.
(a) If the message SLT FPPU 28CV OR WIRING TO SFCC is shown, do the fault isolation.
Subtask 27-81-00-810-055-A
A. Procedure
(1) Swap SFCC1 and SFCC2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(a) Open these circuit breakers:
(c) Wait 60 seconds for SFCC initialization.
(d) Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(e) If the fault moves to the other SFCC position:
1 Install the serviceable SFCC to its initial position.
2 Replace the SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] that shows the fault.
(f) If the fault does not move to the other SFCC position:
1 Install the SFCCs to their initial positions.
2 Do the next step.
(2) Open, safety and tag these circuit breakers:
(b) Remove the safety clips and the tags and close the two circuit breakers.
(c) Wait 60 seconds for SFCC initialization.
(d) Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(e) If the fault moves to the other SFCC:
1 Replace the FPPU-SLAT [28CV]
AMM 27-81-19-000-001 and AMM 27-81-19-400-001.
2 Make sure that the related electrical connectors are correctly installed.
(f) If the fault remains in the same circuit:
1 Open, safety and tag the two circuit breakers.
2 Install the electrical connectors in their initial positions.
3 Do a check and repair the aircraft wiring between the FPPU and the applicable SFCC.
ASM 278106 and ASM 278107.
4 Remove the safety clips and the tags and close the two circuit breakers.
5 Wait 60 seconds for SFCC initialization.
6 Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(3) After the replacement or the repair of the wiring:
5. Close-up(1) Swap SFCC1 and SFCC2
AMM 27-51-34-000-001 and AMM 27-51-34-400-001.
(a) Open these circuit breakers:
- 5CV and
- 7CV.
(c) Wait 60 seconds for SFCC initialization.
(d) Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(e) If the fault moves to the other SFCC position:
1 Install the serviceable SFCC to its initial position.
2 Replace the SLAT/FLAP CONTR.COMP. [21CV] or SLAT/FLAP CONTR.COMP. [22CV] that shows the fault.
(f) If the fault does not move to the other SFCC position:
1 Install the SFCCs to their initial positions.
2 Do the next step.
(2) Open, safety and tag these circuit breakers:
- 5CV and
- 7CV.
(b) Remove the safety clips and the tags and close the two circuit breakers.
(c) Wait 60 seconds for SFCC initialization.
(d) Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(e) If the fault moves to the other SFCC:
1 Replace the FPPU-SLAT [28CV]
AMM 27-81-19-000-001 and AMM 27-81-19-400-001.
2 Make sure that the related electrical connectors are correctly installed.
(f) If the fault remains in the same circuit:
1 Open, safety and tag the two circuit breakers.
2 Install the electrical connectors in their initial positions.
3 Do a check and repair the aircraft wiring between the FPPU and the applicable SFCC.
ASM 278106 and ASM 278107.
4 Remove the safety clips and the tags and close the two circuit breakers.
5 Wait 60 seconds for SFCC initialization.
6 Set the MENU MODE and access the SLT ON GROUND FAULTS and check the ground log.
(3) After the replacement or the repair of the wiring:
- Do the operational test of the slat system AMM 27-84-00-710-001.
Subtask 27-81-00-942-055-A
A. Remove the ground support and maintenance equipment, the special and standard tools and all other items.
Subtask 27-81-00-860-056-A B. Put the aircraft back to its initial configuration.