W DOC AIRBUS | TSM A320F

One Autobrake Mode Pushbutton Switch Inoperative

TASK 32-42-00-810-889-A
One Autobrake Mode Pushbutton Switch Inoperative

1. Possible Causes
  • P/BSW - AUTO BRK/LO (8GG)
  • BSCU [10GG]
  • wiring from the AUTO BRK/LO pushbutton switch (8GG) pin A/A3 to the ground terminal
  • wiring from the AUTO BRK/LO pushbutton switch (8GG) to the BSCU (10GG)
  • P/BSW - AUTO BRK/MED (7GG)
  • wiring from the AUTO BRK/MED pushbutton switch (7GG) pin A/A3 to the ground terminal
  • wiring from the AUTO BRK/MED pushbutton switch (7GG) to the BSCU (10GG)
  • P/BSW - AUTO BRK/MAX (6GG)
  • wiring from the AUTO BRK/MAX pushbutton switch (6GG) pin A/A3 to the ground terminal
  • wiring from the AUTO BRK/MAX pushbutton switch (6GG) to the BSCU (10GG)
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ASM 324203
AMM 32-42-34-000-001
Removal of the Braking/Steering Control Unit (BSCU)
AMM 32-42-34-400-001
Installation of the Braking/Steering Control Unit (BSCU)
3. Fault Confirmation
Subtask 32-42-00-710-074-A
A. Test
   (1) Not applicable.
4. Fault Isolation
Subtask 32-42-00-810-146-A
A. If you cannot engage the AUTO BRAKE mode
   (1) With the AUTO BRK/LO pushbutton switch (8GG)
  • replace the P/BSW - AUTO BRK/LO (8GG) (Ref . AWM 20-45-11)
     (a) If the fault continues:
     (b) If the fault continues:
  • do a check for a ground signal at pin A/A3 of the AUTO BRK/LO pushbutton switch (8GG) ASM 324203.
       1 If there is no ground signal:
  • repair the wiring from the AUTO BRK/LO pushbutton switch (8GG) pin A/A3 to the ground terminal ASM 324203.
       2 If there is a ground signal:
  • do a check and repair the wiring from the AUTO BRK/LO pushbutton switch (8GG) to the BSCU (10GG) pin A/A1 to pin AA/15E ASM 324203.
   (2) With the AUTO BRK/MED pushbutton switch (7GG):
  • replace the P/BSW - AUTO BRK/MED (7GG) (Ref.AWM 20-45-11)
     (a) If the fault continues:
     (b) If the fault continues:
  • do a check for a ground signal at pin A/A3 of the AUTO BRK/MED pushbutton switch (7GG) ASM 324203.
       1 If there is no ground signal:
  • repair the wiring from the AUTO BRK/MED pushbutton switch (7GG) pin A/A3 to the ground terminal ASM 324203.
       2 If there is a ground signal:
  • do a check and repair the wiring from the AUTO BRK/MED pushbutton switch (7GG) to the BSCU (10GG) pin A/A1 to pin AA/14E ASM 324203.
   (3) With the AUTO BRK/MAX pushbutton switch (6GG):
  • replace the P/BSW - AUTO BRK/MAX (6GG). (Ref .AWM 20-45-11)
     (a) If the fault continues:
     (b) If the fault continues:
  • do a check for a ground signal at pin A/A3 of the AUTO BRK/MAX pushbutton switch (6GG) ASM 324203.
       1 If there is a ground signal:
  • repair the wiring from the AUTO BRK/MAX pushbutton switch (6GG) pin A/A3 to the ground terminal ASM 324203.
  • do a check and repair the wiring from the AUTO BRK/MAX pushbutton switch (6GG) to the BSCU (10GG) pin A/A1 to pin AA/13E ASM 324203.
[Rev.8 from Aug 2018] 2026.04.04 04:31:36 UTC
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