Fuel Pumps - Center Tank Autofeed Failure (Pumps Do Not Stop At CTR TK Low Fuel Level)

TASK 28-21-00-810-820-A
Fuel Pumps - Center Tank Autofeed Failure (Pumps Do Not Stop At CTR TK Low Fuel Level)

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

P/BSW-CTR TK/MODE SEL [48QA]
P/BSW-FUEL/CTR TK/PUMP 1 [33QA]
P/BSW-FUEL/CTR TK/PUMP 2 [34QA]
RELAY-CTR TK AUTO CONTROL, PUMP 1(2) 41QA(42QA)
RELAY-CTR TK LOW LEVEL, NO 1(2) 45QA(46QA)
RELAY-CTR TANK PUMP 1(2), LATCHED OFF 67QA(68QA)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-21-00-810-813-A	Fuel Pumps - Center Tank Fuel Pump No. 1 (Left Side) 37QA System Malfunction
TSM TASK 28-21-00-810-814-A	Fuel Pumps - Center Tank Fuel Pump No. 2 (Right Side) 38QA System Malfunction
TSM TASK 28-21-00-810-817-A	Fuel Pumps - Center Tank Fuel Pump No. 1 (Left Side) Contactor Control Failure (Manual Control)
TSM TASK 28-21-00-810-818-A	Fuel Pumps - Center Tank Fuel Pump No. 2 (Right Side) Contactor Control Failure (Manual Control)
AMM 28-21-00-720-001	Functional Test of the Center-Tank Fuel Control

3. Fault Confirmation
Subtask 28-21-00-710-069-B ** ON A/C NOT FOR ALL

A. Test
(1) Do the Functional Test of the Center-Tank Fuel Control (in manual and auto control modes) AMM 28-21-00-720-001.

4. Fault Isolation
Subtask 28-21-00-810-069-F ** ON A/C NOT FOR ALL

A. Procedure
(1) If the:
(a) Center-Tank Fuel Pump No 1 does not operate correctly in the Manual Mode do:
1 Fuel Pumps - Center Tank Pump-Fuel No 1 System Failure (Ref. TSM TASK 28-21-00-810-813).
2 Fuel Pumps - Center Tank Pump-Fuel No 1 Contactor Control Failure (Ref. TSM TASK 28-21-00-810-817).
(b) Center-Tank Fuel Pump No 2 does not operate correctly in the Manual Mode do:
1 Fuel Pumps - Center Tank Pump-Fuel No 2 System Failure (Ref. TSM TASK 28-21-00-810-814).
2 Fuel Pumps - Center Tank Pump-Fuel No 2 Contactor Control Failure (Ref. TSM TASK 28-21-00-810-818).
(2) If a pump does not stop during the test given in Para. 3.A., Auto Mode:

examine the ECAM FUEL System Display page to see which side(s) has/have not shut off correctly.

NOTE: The CTR TANK PUMPS INDICATIONS are:

In line - Green - Pump pressure normal (pump contactor on)
LO - Amber - Pump low pressure (pump contactor on)
Cross line - Green - Pump contactor off and auto shut off required
Cross line - Amber - Pump contactor off and auto shut off not required.

NOTE: For the ECAM warning/caution - AUTO FEED FAULT to have been generated by the FWC, a CTR TK PUMP 1 or 2 AUTO SHUT OFF REQUIRED signal has been received.
This shows that:

the FLSCU-1(2) input of fuel low level (a ground) is correct
the diodes are conducting correctly
the RELAY 45QA(46QA) has operated correctly (energized)
the RELAY 41QA(42QA), contacts C to 6 (the source of the AUTO SHUT OFF REQUIRED signal) have operated correctly (energized).

NOTE: More data about the center-tank fuel-pump auto-control system operation can be got from the TFU Ref. 28.21.00.039.

(3) If one of the (or the two) CTR TK PMPS does not shut off:
(a) Replace the P/BSW-CTR TK/MODE SEL [48QA] .
(b) Do the test given in Para. 3.A.
(4) If the fault continues:
(a) Replace the applicable CTR TK PUMP P/BSW:

P/BSW-FUEL/CTR TK/PUMP 1 [33QA]
P/BSW-FUEL/CTR TK/PUMP 2 [34QA]

(b) Do the test given in Para. 3.A.
(5) If the fault continues, read all of this step. The steps (a) and (b) give two different procedures for troubleshooting the unserviceable condition. Do the one you think is most applicable to the aircrafts location, its next flight and the related maintenace/stores support.
(a) Do a check of the relays that follow and replace, if necessary:

the RELAY-CTR TK AUTO CONTROL, PUMP 1(2) 41QA(42QA) (contacts B to 3)
the RELAY-CTR TK LOW LEVEL, NO 1(2) 45QA(46QA)
the RELAY-CTR TANK PUMP 1(2), LATCHED OFF 67QA(68QA).

1 Do the test given in Para. 3.A.
(b) Do an interchange of (swap) the relays that follow (one related pair at a time, left to right and right to left):

the RELAY-CTR TK AUTO CONTROL, PUMP 1(2) 41QA(42QA)
the RELAY-CTR TK LOW LEVEL, NO 1(2) 45QA(46QA)
the RELAY-CTR TANK PUMP 1(2), LATCHED OFF 67QA(68QA).

1 Make a record of the troubleshooting action taken in the aircraft technical log.
2 If, after the subsequent flight(s) with the first relay swap, the fault:

changes sides, replace the swapped relay on the side that (now) shows the fault
does not change sides, interchange (swap) the second relay given in step (b) and then do step (c).

(c) Make a record of the troubleshooting action taken in the aircraft technical log.
1 If, after the subsequent flight(s) with the second relay swap, the fault:

changes sides, replace the swapped relay on the side that (now) shows the fault
does not change sides, no more troubleshooting work steps are necessary.

(d) Do the test given in Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:28:36 UTC