W DOC AIRBUS | TSM A320F

Loss of the FCU 1 FAIL and FCU 1 HLTY Discretes

TASK 22-81-00-810-808-A
Loss of the FCU 1 FAIL and FCU 1 HLTY Discretes

1. Possible Causes
  • FMGC-1 [1CA1]
  • wiring of the FCU OWN HLTY discrete from the FMGC 1 (1CA1) to the first terminal block
  • wiring of the FCU OWN FAIL discrete from the FMGC 1 (1CA1) to the FCU (2CA)
  • FMGC-2 [1CA2]
  • wiring of the FCU OPP HLTY discrete from the FMGC 2 (1CA2) to the first block terminal
  • FCU [2CA]
  • wiring of the FCU 1 HLTY discrete from the FCU (2CA) to the first terminal block
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 22-81-12-000-001
Removal of the FCU
AMM 22-81-12-400-001
Installation of the FCU
AMM 22-83-34-000-001
Removal of the FMGC
AMM 22-83-34-400-001
Installation of the FMGC
ASM 228504
AMM 22-96-00-710-001
Operational Test of the AFS
3. Fault Confirmation
Subtask 22-81-00-710-063-A
A. Test
   (1) Do the operational test of the AFS AMM 22-96-00-710-001 and read the results for the FMGC 1 and the FMGC 2.
4. Fault Isolation
Subtask 22-81-00-865-055-A
A. Table of the circuit breakers used in this procedure:
PANELDESIGNATIONFINLOCATION
** ON A/C ALL
49VUAUTO FLT/FCU/19CA1B05
49VUAUTO FLT/FMGC/110CA1B02
Subtask 22-81-00-810-059-B
B. If the test gives the maintenance message for the FMGC 1 only:
AFS: FMGC1/FCU (FW DISC1):
   (1) If the fault continues:
  • do a check of the wiring of the FCU OWN HLTY discrete from the FMGC 1 (1CA1) to the first terminal block ASM 228504.
     (a) If there is no continuity:
  • repair the above wiring.
     (b) If there is continuity:
  • do a check and repair the wiring of the FCU OWN FAIL discrete from the FMGC 1 (1CA1) to the FCU (2CA) ASM 228504.
Subtask 22-81-00-810-060-B
C. If the test gives the maintenance message for the FMGC 2 only:
AFS: FMGC2/FCU (FW DISC1):
   (1) If the fault continues:
  • do a check and repair the wiring of the FCU OPP HLTY discrete from the FMGC 2 (1CA2) to the first block terminal ASM 228504.
Subtask 22-81-00-810-061-B
D. If the test gives the maintenance messages for the two FMGCs:
AFS: FMGC1/FCU (FW DISC1) and
AFS: FMGC2/FCU (FW DISC1):
  • open the circuit breaker (10CA1)
  • open the circuit breaker (9CA1)
  • after 5 seconds, close the circuit breaker (9CA1)
  • do the operational test of the AFS AMM 22-96-00-710-001 and read the result for the FMGC 2.
   (1) If the test gives the maintenance message AFS: FMGC2/FCU (FW DISC1):
     (a) If the fault continues:
  • do a check and repair the wiring of the FCU 1 HLTY discrete from the FCU (2CA) to the first terminal block ASM 228504.
   (2) If the test does not give the maintenance message AFS: FMGC2/FCU (FW DISC1):
     (a) If the fault continues:
  • do a check of the wiring of the FW OWN HLTY discrete from the FMGC 1 (1CA1) to the first terminal block ASM 228504.
       1 If there is no continuity:
  • repair the above wiring.
       2 If there is continuity:
  • do a check and repair the wiring of the FCU OWN FAIL discrete from the FMGC 1 (1CA1) to the FCU (2CA) ASM 228504.
Subtask 22-81-00-710-064-A
E. Do the test given in Para. 3.
[Rev.8 from Aug 2018] 2026.04.04 04:25:25 UTC
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