W DOC AIRBUS | TSM A320F

Load-Control Valve (P12) Fault (131-9(A))

TASK 49-00-81-810-855-A
Load-Control Valve (P12) Fault (131-9(A))

1. Possible Causes
  • LOAD VALVE SOLENOID SHOWS CIRCUIT FAILURE
  • damage/contamination of electrical connector P12
  • LOAD CONTROL VALVE (P12)
  • aircraft wiring
  • ELECTRONIC CONTROL BOX [59KD]
  • LOAD CONTROL VALVE (8050KM)
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
AR
MULTIMETER - STANDARD
 B. Referenced Information
REFERENCE
DESIGNATION
AMM 49-51-51-000-004
Removal of the Load Control Valve (131-9(A))
AMM 49-51-51-400-004
Installation of the Load Control Valve (131-9(A))
ASM 496104
AMM 49-61-34-000-003
Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-003
Installation of the Electronic Control Box (ECB) (131-9(A))
3. Fault Confirmation
Subtask 49-00-81-710-058-A ** ON A/C NOT FOR ALL
A. Read-out of ECB Trouble-Shooting Data
   (1) Put the APU MASTER SW to the ON position.
   (2) Get access to the APU LAST LEG/PREVIOUS LEG report.
   (3) Push the '>' adjacent to the related CFDS failure message:
  • the MCDU menu shows
    LOAD VALVE SOLENOID SHOWS CIRCUIT FAILURE
   (4) Get access to the APU GND SCANNING menu.
4. Fault Isolation
Subtask 49-00-81-810-056-A ** ON A/C NOT FOR ALL
A. If the APU GND SCANNING menu gives the maintenance message:

LOAD CONTROL VALVE P12

associated with Fault Code Number (FCN) 127

  • do a check for damage/contamination of electrical connector P12 of the LOAD CONTROL VALVE (P12).
   (1) If the electrical connector P12 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 1 and pin 2 of the LOAD CONTROL VALVE (P12)
    pin 1 and pin 5 of the LOAD CONTROL VALVE (P12)
     (a) If the resistance is
not between 15 Ohms to 80 Ohms (pin 1-2)
or
< 100K Ohms (pin 1-5):
     (b) If the resistance is
between 15 Ohms and 80 Ohms (pin 1-2)
and
> 100K Ohms (pin 1-5):
  • do a check and repair of the aircraft wiring between the
    ECB (59KD) AB/F10 and the LOAD CONTROL VALVE (P12) P12/1
    and/or LOAD CONTROL VALVE (P12) P12/2 and aircraft GND ASM 496104.
       1 If the fault continues:
Subtask 49-00-81-810-056-B ** ON A/C NOT FOR ALL
A. If the APU GND SCANNING menu gives the maintenance message:

LOAD CONTROL VALVE (8050KM)

associated with Fault Code Number (FCN) 127

  • do a check for damage/contamination of electrical connector P12 of the LOAD CONTROL VALVE (8050KM)
   (1) If the electrical connector P12 is damaged/contaminated:
  • do a repair/cleaning.
   (2) If the electrical connector is OK:
  • use a MULTIMETER - STANDARD to do a resistance check across
    pin 1 and pin 2 of the LOAD CONTROL VALVE (8050KM)
    pin 1 and pin 5 of the LOAD CONTROL VALVE (8050KM)
     (a) If the resistance is
not between 15 Ohms to 80 Ohms (pin 1-2)
or
< 100K Ohms (pin 1-5):
     (b) If the resistance is
between 15 Ohms and 80 Ohms (pin 1-2)
and
> 100K Ohms (pin 1-5):
  • do a check and repair of the aircraft wiring between the
    ECB (59KD) AB/F10 and the LOAD CONTROL VALVE (8050KM) P12/1
    and/or LOAD CONTROL VALVE (8050KM) P12/2 and aircraft GND ASM 496104.
       1 If the fault continues:
Subtask 49-00-81-710-059-A ** ON A/C NOT FOR ALL
B. Do a check of the APU GND SCANNING menu to verify the fault is not present.
[Rev.8 from Aug 2018] 2026.04.04 04:34:36 UTC
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