DOC AIRBUS | TSM A320FL(R) Low Level Sensor 16QJ1(2)
TASK 28-46-00-810-802-A
L(R) Low Level Sensor 16QJ1(2)
A. Referenced Information
3. Fault Confirmation
Subtask 28-46-00-740-051-A ** ON A/C NOT FOR ALL
Subtask 28-46-00-810-051-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:29:13 UTC
L(R) Low Level Sensor 16QJ1(2)
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-1 [7QJ]
- aircraft wiring
- HARNESS-CHAN A, L WING TK INR [13QT1]
- HARNESS-CHAN A, R WING TK INR [13QT2]
- SENSOR-LOW LEVEL (750KG),L WNG TK INR REAR CHANNEL A [16QJ1]
- SENSOR-LOW LEVEL (750KG),R WNG TK INR REAR CHANNEL A [16QJ2]
- FLSCU-2 [9QJ]
- HARNESS-LEFT WING TANK A [57QT]
- HARNESS-RIGHT WING, TANK A [58QT]
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 28-46-00-810-818-A | FLSCU1(2) 7QJ(9QJ) |
| ESPM 2053210 | |
| AMM 28-10-00-910-001 | Safety Procedures When You Do Work in a Fuel Tank |
| AMM 28-10-00-910-002 | Access to the Fuel Tanks and the Work Areas |
| AMM 28-42-43-000-005 | Removal of the Wing Tank Harness |
| AMM 28-42-43-000-006 | Removal of the Wing-Tank Inner-Cell Group A Harness |
| AMM 28-42-43-000-008 | Removal of the Wing Tank Fuel Quantity Indicating Probe Fused/Shorting Plug Connectors |
| AMM 28-42-43-400-005 | Installation of the Wing Tank Harness |
| AMM 28-42-43-400-006 | Installation of the Wing-Tank Inner-Cell Group A Harness |
| AMM 28-46-00-740-001 | Functional (BITE) Test |
| ASM 284602 | |
| AWM 284604 | |
| AWM 284605 | |
| AWM 284606 | |
| AMM 28-46-15-000-001 | Removal of the Wing-Tank Fuel-Level Sensors |
| AMM 28-46-15-400-009 | Installation of the Wing-Tank Fuel-Level Sensors |
| 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) |
Subtask 28-46-00-740-051-A ** ON A/C NOT FOR ALL
A. Test
(1) Do the BITE test of the FLSS AMM 28-46-00-740-001.
(2) Examine the FLSS STATUS page on the MCDU.
(3) If the page shows messages for one or more of the other sensors and/or the FLSCU-1, do (Ref. TSM TASK 28-46-00-810-818).
(4) If the message 284615 L(R) LO LEVEL SENSOR 16QJ1(2):
Subtask 28-46-00-740-051-B ** ON A/C NOT FOR ALL (1) Do the BITE test of the FLSS AMM 28-46-00-740-001.
(2) Examine the FLSS STATUS page on the MCDU.
(3) If the page shows messages for one or more of the other sensors and/or the FLSCU-1, do (Ref. TSM TASK 28-46-00-810-818).
(4) If the message 284615 L(R) LO LEVEL SENSOR 16QJ1(2):
- is shown, do Para. 4.A.
- is not shown, no work steps are necessary.
NOTE: You can get more data from the:
- Aircraft Maintenance Manual (AMM) Chap. 28-46-00, the Fuel Level Sensing System, Description and Operation (D and O)
- Trouble Shooting Manual (TSM) - Task Supporting Data (Ref. P. Block 301)
- Aircraft Schematic Manual (ASM) ASM 284602.
- Input Parameters Page 3 (Ref. P. Block 301), used with the Fuel Level Sensors Operating (Changeover) Values (Ref. P. Block 301)
- FLSCU Trouble-shooting Data (Ref. P. Block 301).
NOTE: OPTIONAL TESTING:
Where a PSD A320-2 Fuel Level Sensing Test Set is available measurements can be taken before a decision is made to go into or close up a fuel tank. The Test Set enables the tank mounted components and tank wiring to be tested from the tank wall connectors.
Where a PSD A320-2 Fuel Level Sensing Test Set is available measurements can be taken before a decision is made to go into or close up a fuel tank. The Test Set enables the tank mounted components and tank wiring to be tested from the tank wall connectors.
A. Test
(1) Do the BITE test of the FLSS AMM 28-46-00-740-001.
(2) Examine the FLSS STATUS page on the MCDU.
(3) If the page shows messages for one or more of the other sensors and/or the FLSCU-1(2), do (Ref. TSM TASK 28-46-00-810-818).
(4) If the message 284615 L(R) LO LEVEL SENSOR 16QJ1(2):
4. Fault Isolation(1) Do the BITE test of the FLSS AMM 28-46-00-740-001.
(2) Examine the FLSS STATUS page on the MCDU.
(3) If the page shows messages for one or more of the other sensors and/or the FLSCU-1(2), do (Ref. TSM TASK 28-46-00-810-818).
(4) If the message 284615 L(R) LO LEVEL SENSOR 16QJ1(2):
- is shown, do Para. 4.A.
- is not shown, no work steps are necessary.
NOTE: You can get more data from the:
- Aircraft Maintenance Manual (AMM) Chap. 28-46-00, the Fuel Level Sensing System, Description and Operation (D and O)
- Trouble Shooting Manual (TSM) - Task Supporting Data (Ref. P. Block 301)
- Aircraft Schematic Manual (ASM) ASM 284602.
- Input Parameters Page 3 (Ref. P. Block 301), used with the Fuel Level Sensors Operating (Changeover) Values (Ref. P. Block 301)
- Trouble-shooting Data (Ref. P. Block 301).
NOTE: OPTIONAL TESTING:
Where a PSDA321-1 Test Set is available, a check can be made before a decision is made to go into or close up a fuel tank. The Test Set enables a GO/NOGO check to be made of the tank mounted components and wiring from the tank wall connectors.
Where a PSDA321-1 Test Set is available, a check can be made before a decision is made to go into or close up a fuel tank. The Test Set enables a GO/NOGO check to be made of the tank mounted components and wiring from the tank wall connectors.
Subtask 28-46-00-810-051-A ** ON A/C NOT FOR ALL
A. Procedure
(1) Do the steps applicable to the test equipment available.
(2) Test Equipment.
(4) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(5) Do a resistance check of the sensor 16QJ1(2) at the tank wall connector 4039VC1(2) between pins <G and <W AWM 284604.
Make sure the resistance is between 330 and 480 ohms.
If there is:
(7) If the fault continues:
(a) Get access to the tank wall connector 4039VC1(2)-A (for the wing tank harness 13QT1(2)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(c) Do a check AWM 284604 of the aircraft wiring (sensor input line - H) between the FLSCU-1 rack connector AB, pin 15A and the tank wall free connector 4039VC1-A, pin <G, or the (aircraft wiring (sensor input line - H) between the FLSCU-1 rack connector AB, pin 8A and the tank wall free connector 4039VC2-A, pin <G).
(d) Do a check AWM 284604 of the aircraft wiring (sensor input line - L) between the FLSCU-1 rack connector AB, pin 15B and the tank wall free connector 4039VC1-A, pin <W, or the (aircraft wiring (sensor input line - L) between the FLSCU-1 rack connector AB, pin 8B and the tank wall free connector 4039VC2-A, pin <W).
(e) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 BITE 2 test command line) between the FLSCU-1 rack connector AA, pin 15A and the FQIC rack connector AB, pin 7J, or the (aircraft wiring (FLSCU-1 BITE 3 test command line) between the FLSCU-1 rack connector AA, pin 15C and the FQIC rack connector AB, pin 8H).
(f) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 LS1 output line) between the FLSCU-1 rack connector AB, pin 1A and the FQIC rack connector AB, pin 2J, or the (aircraft wiring (FLSCU-1 LS5 output line) between the FLSCU-1 rack connector AB, pin 5B and the FQIC rack connector AB, pin 5G).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4039VC1(2)-A to the receptacle 4039VC1(2).
(i) Do the test in Para. 3.A.
(8) If the fault continues or if there is no continuity in Step (5):
(a) Drain, open and vent the tank AMM 28-10-00-910-001 and AMM 28-10-00-910-002.
(b) Do a wiring check of the HARNESS-CHAN A, L WING TK INR [13QT1] ( HARNESS-CHAN A, R WING TK INR [13QT2] ) AWM 284604 and replace, if necessary AMM 28-42-43-000-006 and AMM 28-42-43-400-006.
(c) If the harness is serviceable, replace the SENSOR-LOW LEVEL (750KG),L WNG TK INR REAR CHANNEL A [16QJ1] ( SENSOR-LOW LEVEL (750KG),R WNG TK INR REAR CHANNEL A [16QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009.
Subtask 28-46-00-810-051-B ** ON A/C NOT FOR ALL (1) Do the steps applicable to the test equipment available.
(2) Test Equipment.
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.
(a) If there is: - approved test equipment available, go to Step (3)
- no approved test equipment available, go to Step (6).
(4) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(5) Do a resistance check of the sensor 16QJ1(2) at the tank wall connector 4039VC1(2) between pins <G and <W AWM 284604.
Make sure the resistance is between 330 and 480 ohms.
If there is:
- continuity as specified above, go to Step (6)
- no continuity as specified above (resistance check out of range), go to Step (8).
NOTE: The sensor status (wet or dry) and fuel/air temperature will have an effect on the resistance value.
(6) Replace the FLSCU-1 [7QJ] AMM 28-46-34-000-001 and AMM 28-46-34-400-001. (7) If the fault continues:
(a) Get access to the tank wall connector 4039VC1(2)-A (for the wing tank harness 13QT1(2)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(c) Do a check AWM 284604 of the aircraft wiring (sensor input line - H) between the FLSCU-1 rack connector AB, pin 15A and the tank wall free connector 4039VC1-A, pin <G, or the (aircraft wiring (sensor input line - H) between the FLSCU-1 rack connector AB, pin 8A and the tank wall free connector 4039VC2-A, pin <G).
(d) Do a check AWM 284604 of the aircraft wiring (sensor input line - L) between the FLSCU-1 rack connector AB, pin 15B and the tank wall free connector 4039VC1-A, pin <W, or the (aircraft wiring (sensor input line - L) between the FLSCU-1 rack connector AB, pin 8B and the tank wall free connector 4039VC2-A, pin <W).
(e) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 BITE 2 test command line) between the FLSCU-1 rack connector AA, pin 15A and the FQIC rack connector AB, pin 7J, or the (aircraft wiring (FLSCU-1 BITE 3 test command line) between the FLSCU-1 rack connector AA, pin 15C and the FQIC rack connector AB, pin 8H).
(f) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 LS1 output line) between the FLSCU-1 rack connector AB, pin 1A and the FQIC rack connector AB, pin 2J, or the (aircraft wiring (FLSCU-1 LS5 output line) between the FLSCU-1 rack connector AB, pin 5B and the FQIC rack connector AB, pin 5G).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4039VC1(2)-A to the receptacle 4039VC1(2).
(i) Do the test in Para. 3.A.
(8) If the fault continues or if there is no continuity in Step (5):
(a) Drain, open and vent the tank AMM 28-10-00-910-001 and AMM 28-10-00-910-002.
(b) Do a wiring check of the HARNESS-CHAN A, L WING TK INR [13QT1] ( HARNESS-CHAN A, R WING TK INR [13QT2] ) AWM 284604 and replace, if necessary AMM 28-42-43-000-006 and AMM 28-42-43-400-006.
(c) If the harness is serviceable, replace the SENSOR-LOW LEVEL (750KG),L WNG TK INR REAR CHANNEL A [16QJ1] ( SENSOR-LOW LEVEL (750KG),R WNG TK INR REAR CHANNEL A [16QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009.
A. Procedure
(1) Do the steps applicable to the test equipment available.
(2) Test Equipment.
(4) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(5) Do a resistance check of the sensor 16QJ1(2) at the tank wall connector 4039VC1(2) between pins <G and <W AWM 284604.
Make sure the resistance is between 330 and 480 ohms.
If there is:
(7) If the fault continues:
(a) Get access to the tank wall connector 4039VC1(2)-A (for the wing tank harness 57QT(58QT)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(c) Do a check AWM 284604, and AWM 284605 of the aircraft wiring (sensor input line - H) between the FLSCU-1(2) rack connector AB, pin 15A and the tank wall free connector 4039VC1(2)-A, pin <G.
(d) Do a check AWM 284604, and AWM 284605 of the aircraft wiring (sensor input line - L) between the FLSCU-1(2) rack connector AB, pin 15B and the tank wall free connector 4039VC1(2)-A, pin <W.
(e) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 BITE 2 test command line) between the FLSCU-1 rack connector AA, pin 15A and the FQIC rack connector AB, 14E, or the (aircraft wiring (FLSCU-2 BITE 2 test command line) between the FLSCU-2 rack connector AA, pin 15A and the FQIC rack connector AB, 12E).
(f) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 LS1 output line) between the FLSCU-1 rack connector AB, pin 1A and the FQIC rack connector AC, 4D, or the (aircraft wiring (FLSCU-2 LS1 output line) between the FLSCU-2 rack connector AB, pin 1A and the FQIC rack connector AC, 2G).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4039VC1(2)-A to the receptacle 4039VC1(2).
(i) Do the test in Para. 3.A.
(8) If the fault continues or if there is no continuity in Step (5):
(a) Drain, open and vent the tank AMM 28-10-00-910-001 and AMM 28-10-00-910-002.
(b) Do a wiring check of the HARNESS-LEFT WING TANK A [57QT] ( HARNESS-RIGHT WING, TANK A [58QT] ) AWM 284604 and replace, if necessary AMM 28-42-43-000-005 and AMM 28-42-43-400-005.
(c) If the harness is serviceable, replace the SENSOR-LOW LEVEL (750KG),L WNG TK INR REAR CHANNEL A [16QJ1] ( SENSOR-LOW LEVEL (750KG),R WNG TK INR REAR CHANNEL A [16QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009.
(1) Do the steps applicable to the test equipment available.
(2) Test Equipment.
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.
(a) If there is: - approved test equipment available, go to Step (3)
- no approved test equipment available, go to Step (6)
(4) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(5) Do a resistance check of the sensor 16QJ1(2) at the tank wall connector 4039VC1(2) between pins <G and <W AWM 284604.
Make sure the resistance is between 330 and 480 ohms.
If there is:
- continuity as specified above, go to Step (6)
- no continuity as specified above (resistance check out of range), go to Step (8).
NOTE: The sensor status (wet or dry) and fuel/air temperature will have an effect on the resistance value.
(6) Replace the FLSCU-1 [7QJ] ( FLSCU-2 [9QJ] ), AMM 28-46-34-000-001 and AMM 28-46-34-400-001. (7) If the fault continues:
(a) Get access to the tank wall connector 4039VC1(2)-A (for the wing tank harness 57QT(58QT)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4039VC1(2)-A from the receptacle 4039VC1(2).
(c) Do a check AWM 284604, and AWM 284605 of the aircraft wiring (sensor input line - H) between the FLSCU-1(2) rack connector AB, pin 15A and the tank wall free connector 4039VC1(2)-A, pin <G.
(d) Do a check AWM 284604, and AWM 284605 of the aircraft wiring (sensor input line - L) between the FLSCU-1(2) rack connector AB, pin 15B and the tank wall free connector 4039VC1(2)-A, pin <W.
(e) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 BITE 2 test command line) between the FLSCU-1 rack connector AA, pin 15A and the FQIC rack connector AB, 14E, or the (aircraft wiring (FLSCU-2 BITE 2 test command line) between the FLSCU-2 rack connector AA, pin 15A and the FQIC rack connector AB, 12E).
(f) Do a check AWM 284606 of the aircraft wiring (FLSCU-1 LS1 output line) between the FLSCU-1 rack connector AB, pin 1A and the FQIC rack connector AC, 4D, or the (aircraft wiring (FLSCU-2 LS1 output line) between the FLSCU-2 rack connector AB, pin 1A and the FQIC rack connector AC, 2G).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4039VC1(2)-A to the receptacle 4039VC1(2).
(i) Do the test in Para. 3.A.
(8) If the fault continues or if there is no continuity in Step (5):
(a) Drain, open and vent the tank AMM 28-10-00-910-001 and AMM 28-10-00-910-002.
(b) Do a wiring check of the HARNESS-LEFT WING TANK A [57QT] ( HARNESS-RIGHT WING, TANK A [58QT] ) AWM 284604 and replace, if necessary AMM 28-42-43-000-005 and AMM 28-42-43-400-005.
(c) If the harness is serviceable, replace the SENSOR-LOW LEVEL (750KG),L WNG TK INR REAR CHANNEL A [16QJ1] ( SENSOR-LOW LEVEL (750KG),R WNG TK INR REAR CHANNEL A [16QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009.