W DOC AIRBUS | TSM A320F

Dummy Temperature Sensor 42QJ

TASK 28-46-00-810-844-A
Dummy Temperature Sensor 42QJ

WARNING: OBEY THE FUEL SAFETY PROCEDURES.
WARNING: WHEN YOU DO WORK ON THE FUEL SYSTEM WIRING, YOU MUST USE TEST EQUIPMENT THAT IS APPROVED (REFER TO INTERNATIONAL OR NATIONAL SPECIFICATIONS FOR INTRINSICALLY SAFE TEST EQUIPMENT: EN50020, UL913 OR EQUIVALENT). TEST EQUIPMENT THAT IS NOT APPROVED CAN CAUSE FIRE OR AN EXPLOSION.
1. Possible Causes
  • FLSCU-2 [9QJ]
  • aircraft wiring
  • RESISTOR [42QJ]
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
TSM TASK 28-46-00-810-818-A
FLSCU1(2) 7QJ(9QJ)
ESPM 2044510
ESPM 2052210
ESPM 2052220
ESPM 2053210
AIPC 25710125
AMM 28-42-00-740-003
Interrogation of the FQIS Input Parameters Pages
AMM 28-42-00-740-009
Interrogation of the (SIMMONDS/GOODRICH) FQIS Trouble Shooting Data
AMM 28-46-00-00-
AMM 28-46-00-740-001
Functional (BITE) Test
ASM 284604
AIPC 28460802
AWM 284612
AMM 28-46-34-000-001
Removal of the Fuel-Level Sensing Control-Unit (FLSCU)
AMM 28-46-34-400-001
Installation of the Fuel-Level Sensing Control-Unit (FLSCU)
AWM 930092
3. Fault Confirmation
Subtask 28-46-00-710-075-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the Functional (BITE) test of the FLSS AMM 28-46-00-740-001.
   (2) Examine the FLSS STATUS page.
   (3) If the page shows messages for one or more of the other sensors and/or the FLSCU-2, do the FLSCU1(2) 7QJ(9QJ) troubleshooting (Ref. TSM TASK 28-46-00-810-818).
   (4) If the message 284617 DUMMY TEMP SENSOR 42QJ:

  • is not shown, no (troubleshooting) work steps are necessary

  • is shown, do Para. 4.A.
NOTE: You can get more (descriptive) data from the:
  • Description and Operation section of the Aircraft Maintenance Manual (AMM), the Fuel Level Sensing System (FLSS) AMM 28-46-00-00-
  • Trouble Shooting Manual (TSM) - Task Supporting Data (Ref. P. Block 301)
  • Aircraft Schematic Manual (ASM) ASM 284604.
NOTE: You can get more (troubleshooting) data from the CFDS(FUEL):
4. Fault Isolation
Subtask 28-46-00-810-093-A ** ON A/C NOT FOR ALL
A. Procedure
   (1) Remove the FLSCU-2 (9QJ) AMM 28-46-34-000-001 and keep in a safe position.
NOTE: This action isolates the dummy sensor from its input circuit in the FLSCU-2 (9QJ) temperature sensor channel T2.
   (2) In the forward avionics compartment, get access to the terminal block 202VT (92VU) AMM 28-46-34-000-001 AWM 930092 and AIPC 25710125.
   (3) Do a resistance check of the dummy sensor 42QJ (a resistor) at the terminal block 202VT between the terminals 23F and 23K AWM 284612 and ESPM 2052210.
     (a) Make sure that the resistance is between 135 and 165 ohms.
     (b) If the resistance:

  • is within the range as specified above, go to step (4)

  • is not within the range as specified above or open circuit, go to step (6).
   (4) Replace the FLSCU-2 [9QJ] AMM 28-46-34-000-001 and AMM 28-46-34-400-001.
   (5) If the fault continues:
     (a) Remove the FLSCU-2 (9QJ) AMM 28-46-34-000-001.
     (b) Do a check of the FLSS aircraft wiring as given in the steps that follow:
       1 Each wire is to be tested for:
         a Continuity ESPM 2052210.
         b Insulation resistance/test for short circuit (wire to ground) ESPM 2052220.
         c Insulation resistance/test for short circuit (wire to adjacent wires) ESPM 2052220.
       2 Between the FLSCU-2 rack connector 9QJ-AB, pin 7D and the terminal block 202VT, terminal 23A (dummy sensor input line - H) AWM 284612.
       3 Between the FLSCU-2 rack connector 9QJ-AB, pin 7C and the terminal block 202VT, terminal 23H (dummy sensor input line - L) AWM 284612.
       4 Between the FLSCU-2 rack connector 9QJ-AA, pin 15D and the FQIC rack connector 3QT-AB, pin 13E (FLSCU-2 BITE 4 test command line) AWM 284612.
       5 Between the FLSCU-2 rack connector 9QJ-AB, pin 4D and the FQIC rack connector 3QT-AC, pin 4F (FLSCU-2 T2 output line) AWM 284612.
     (c) Repair all the unserviceable wiring and connectors ESPM 2053210.
     (d) Install the FLSCU-2 (9QJ) AMM 28-46-34-400-001.
     (e) Do the test in Para. 3.A.
   (6) If the fault continues or if the resistance of the dummy sensor is not as specified in step (3):
     (a) Replace the RESISTOR [42QJ] AIPC 28460802 and ESPM 2044510.
     (b) If necessary, install the FLSCU-2 (9QJ) AMM 28-46-34-400-001.
     (c) Do the test in Para. 3.A.
[Rev.8 from Aug 2018] 2026.04.04 04:29:18 UTC
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