L(R) Full Level Sensor 2 27QJ1(2)

TASK 28-46-00-810-811-A
L(R) Full Level Sensor 2 27QJ1(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]
FLSCU-2 [9QJ]
aircraft wiring
HARNESS-CHAN B, L WING TK INR [14QT1]
HARNESS-CHAN B, R WING TK INR [14QT2]
SENSOR-FULL LVL, L WNG TK INR 2 CHANNEL B [27QJ1]
SENSOR-FULL LVL, R WNG TK INR 2 CHANNEL B [27QJ2]
HARNESS-LEFT WING TANK B [63QT]
HARNESS-RIGHT WING TANK B [64QT]

2. Job Set-up Information
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 28-42-43-000-007	Removal of the Wing-Tank Inner-Cell Group B 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 28-42-43-400-007	Installation of the Wing-Tank Inner-Cell Group B Harness
AMM 28-46-00-740-001	Functional (BITE) Test
ASM 284603
AWM 284607
AWM 284608
AWM 284610
AWM 284611
AWM 284612
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)

3. Fault Confirmation
Subtask 28-46-00-740-060-C ** 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(2), do (Ref. TSM TASK 28-46-00-810-818).
(4) If the message 284615 L(R) FULL SENSOR 27QJ1(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 284603.

You can get more Trouble-shooting data from the CFDS(FUEL):

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.

Subtask 28-46-00-740-060-D ** ON A/C NOT FOR ALL

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 284603.

You can get more Trouble-shooting data from the CFDS(FUEL):

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.

4. Fault Isolation
Subtask 28-46-00-810-060-C ** ON A/C NOT FOR ALL

A. Procedure
(1) Do the steps applicable to the test equipment available.
(2) Test Equipment.

(a) If there is:

approved test equipment available, go to Step (3)
no approved test equipment available, go to Step (6).

(3) Get access to the tank wall connector 4040VC1(2)-A (for the wing tank harness 14QT1(2)) AMM 28-42-43-000-008.
(4) Disconnect the free connector 4040VC1(2)-A from the receptacle 4040VC1(2).
(5) Do a resistance check of the sensor 27QJ1(2) at the tank wall connector 4040VC1(2) between pins <E and <F AWM 284607 ( AWM 284608).
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 4040VC1(2)-A (for the wing tank harness 14QT1(2)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4040VC1(2)-A from the receptacle 4040VC1(2).
(c) Do a check AWM 284607, and AWM 284608 of the aircraft wiring (sensor input line - H) between the FLSCU-1(2) rack connector AB, pin 13D and the tank wall free connector 4040VC1(2)-A, pin <E.
(d) Do a check AWM 284607, and AWM 284608 of the aircraft wiring (sensor input line - L) between the FLSCU-1(2) rack connector AB, pin 13C and the tank wall free connector 4040VC1(2)-A, pin <F.
(e) Do a check AWM 284611 of the aircraft wiring (FLSCU-1 BITE 4 test command line) between the FLSCU-1 rack connector AA, pin 15D and the FQIC rack connector AB, pin 7K or ( AWM 284612 of the aircraft wiring (FLSCU-2 BITE 4 test command line) between the FLSCU-2 rackconn ector AA, pin 15D and the FQIC rack connector AB, pin 9H).
(f) Do a check AWM 284610 of the aircraft wiring (FLSCU-1 LS12 output line) between the FLSCU-1 rack connector AB, pin 3C and the FQIC rack connector AB, pin 4H or the (aircraft wiring (FLSCU-2 LS12 output line) between the FLSCU-2 rack connector AB, pin 3C and the FQIC rack connector AB, pin 13H).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4040VC1(2)-A to the receptacle 4040VC1(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 B, L WING TK INR [14QT1] ( HARNESS-CHAN B, R WING TK INR [14QT2] ) AWM 284607 ( AWM 284608) and replace, if necessary AMM 28-42-43-000-007 and AMM 28-42-43-400-007.
(c) If the harness is serviceable, replace the SENSOR-FULL LVL, L WNG TK INR 2 CHANNEL B [27QJ1] ( SENSOR-FULL LVL, R WNG TK INR 2 CHANNEL B [27QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009

Subtask 28-46-00-810-060-E ** ON A/C NOT FOR ALL

A. Procedure
(1) Do the steps applicable to the test equipment available.
(2) Test Equipment.

(a) If there is:

approved test equipment available, go to Step (3)
no approved test equipment available, go to Step (6).

(3) Get access to the tank wall connector 4040VC1(2)-A (for the wing tank harness 63QT(64QT)) AMM 28-42-43-000-008.
(4) Disconnect the free connector 4040VC1(2)-A from the receptacle 4040VC1(2).
(5) Do a resistance check of the sensor 27QJ1(2) at the tank wall connector 4040VC1(2) between pins <E and <F AWM 284607 ( AWM 284608).
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 4040VC1(2)-A (for the wing tank harness 63QT(64QT)) AMM 28-42-43-000-008.
(b) Disconnect the free connector 4040VC1(2)-A from the receptacle 4040VC1(2).
(c) Do a check AWM 284607, and AWM 284608 of the aircraft wiring (sensor input line - H) between the FLSCU-1(2) rack connector AB, pin 13D and the tank wall free connector 4040VC1(2)-A, pin <E.
(d) Do a check AWM 284607, and AWM 284608 of the aircraft wiring (sensor input line - L) between the FLSCU-1(2) rack connector AB, pin 13C and the tank wall free connector 4040VC1(2)-A, pin <F.
(e) Do a check AWM 284611 of the aircraft wiring (FLSCU-1 BITE 4 test command line) between the FLSCU-1 rack connector AA, pin 15D and the FQIC rack connector AB, pin 15E or ( AWM 284612 of the aircraft wiring (FLSCU-2 BITE 4 test command line) between the FLSCU-2 rack connector AA, pin 15D and the FQIC rack connector AB, pin 13E).
(f) Do a check AWM 284610 of the aircraft wiring (FLSCU-1 LS12 output line) between the FLSCU-1 rack connector AB, pin 3C and the FQIC rack connector AC, pin 3H or the (aircraft wiring (FLSCU-2 LS12 output line) between the FLSCU-2 rack connector AB, pin 3C and the FQIC rack connector AC, pin 1E).
(g) Repair all the unserviceable wiring and connectors ESPM 2053210.
(h) Connect the free connector 4040VC1(2)-A to the receptacle 4040VC1(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 B [63QT] ( HARNESS-RIGHT WING TANK B [64QT] ) AWM 284607 ( AWM 284608) 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-FULL LVL, L WNG TK INR 2 CHANNEL B [27QJ1] ( SENSOR-FULL LVL, R WNG TK INR 2 CHANNEL B [27QJ2] ) AMM 28-46-15-000-001 and AMM 28-46-15-400-009

[Rev.8 from Aug 2018] 2026.04.04 04:29:15 UTC