Fuel Pumps - Center Tank Fuel Pump No. 1 (Left Side) 37QA System Malfunction
TASK 28-21-00-810-813-A
Fuel Pumps - Center Tank Fuel Pump No. 1 (Left Side) 37QA System Malfunction
A. Fixtures, Tools, Test and Support Equipment
B. Referenced Information
3. Fault Confirmation
Subtask 28-21-00-865-056-A ** ON A/C NOT FOR ALL
Subtask 28-21-00-810-063-C ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:28:35 UTC
Fuel Pumps - Center Tank Fuel Pump No. 1 (Left Side) 37QA System Malfunction
WARNING:
OBEY THE FUEL SAFETY PROCEDURES.
WARNING:
DO NOT CLOSE OR RESET:
- AN OPEN (TRIPPED) MECHANICAL CIRCUIT BREAKER
- A TRIPPED GFI
- FIRE OR EXPLOSION
- DAMAGE TO THE AIRCRAFT WIRING AND STRUCTURE.
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- C/B-FUEL/CTR TK/PUMP1 SPLY [29QA]
- CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA]
- PUMP-FUEL NO 1, CTR TK [37QA]
- aircraft wiring
- PRESS SW-FUEL PUMP NO 1, CTR TK [39QA]
- pressure switch safety valve
pressure switch plug (banjo adaptor attachment bolt) - pressure switch fuel supply pipe-line between the fuel pump canister 84QM and the pressure switch 39QA
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | MEGOHMMETER 200 MOHMS - 500 VDC, 0.001 A MAX |
| No specific | 1 | MULTIMETER - STANDARD |
| 99A28404000000 | 1 | ADAPTOR-SEQUENCE VALVE |
| REFERENCE | DESIGNATION |
|---|---|
| TSM TASK 28-21-00-810-829-A | Fuel - Loss of Power supply to the Center Tank Pump 1(2) |
| ESPM 203136 | |
| ESPM 2031360 | |
| ESPM 2052210 | |
| ESPM 2052240 | |
| ASM 245802 | |
| AMM 28-18-00-710-801 | Operational Check of Center-Tank Fuel-Pump GFI |
| AMM 28-21-00-040-002 | Deactivation of the Center Tank |
| AMM 28-21-00-710-007 | Operational Test of the Main Fuel-Pump System with Fuel Flow by Transfer |
| AMM 28-21-00-720-001 | Functional Test of the Center-Tank Fuel Control |
| ASM 282103 | |
| AWM 282105 | |
| AMM 28-21-15-000-003 | Removal of the Fuel-Pump Pressure-Switch |
| AMM 28-21-15-400-001 | Installation of the Fuel-Pump Pressure-Switch |
| AMM 28-21-45-400-003 | Installation of the Sequence Valve |
| AMM 28-21-51-000-002 | Removal of the Fuel Pumps |
| AMM 28-21-51-400-002 | Installation of the Fuel Pumps |
| AMM 32-12-00-010-001 | Open the Main Gear Doors for Access |
| AMM 51-76-12-300-001 | Local Repair of the Fuel Tank Sealant |
| AMM 51-76-12-300-002 | Repair of the Fuel Tank Fillet |
| SRM 530000 | |
| AWM 930107 | |
| AWM 930120 | |
| AWM 930121 |
Subtask 28-21-00-865-056-A ** ON A/C NOT FOR ALL
A. Table of the circuit breakers referred to in this procedure:
Subtask 28-21-00-710-063-C ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C NOT FOR ALL | |||
| 121VU | FUEL/CTR TK/PUMP1 SPLY | 29QA | P23 |
B. Test
(2) If the C/B-29QA or GFI 69QA are open (tripped), do the Fuel - Loss of Power supply to the Center Tank Pump 1(2) (Ref. TSM TASK 28-21-00-810-829).
(3) If the C/B-29QA and GFI 69QA are closed, do the Functional Test of the Center-Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
4. Fault IsolationWARNING:
DO NOT CLOSE OR RESET:
(1) Examine the C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] and CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] . - AN OPEN (TRIPPED) MECHANICAL CIRCUIT BREAKER
- A TRIPPED GFI
- FIRE OR EXPLOSION
- DAMAGE TO THE AIRCRAFT WIRING AND STRUCTURE.
(2) If the C/B-29QA or GFI 69QA are open (tripped), do the Fuel - Loss of Power supply to the Center Tank Pump 1(2) (Ref. TSM TASK 28-21-00-810-829).
(3) If the C/B-29QA and GFI 69QA are closed, do the Functional Test of the Center-Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
Subtask 28-21-00-810-063-C ** ON A/C NOT FOR ALL
A. Procedure.
(1) Do the operational test of the GFI 69QA AMM 28-18-00-710-801.
(a) If there is a fault with the GFI CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] , replace it.
or
(b) If MMEL conditions apply, deactivate the PUMP-FUEL NO 1, CTR TK [37QA] AMM 28-21-00-040-002. (Ref. MMEL 28-21-02 Center Tank Fuel Pump).
(2) If a fuel low pressure indication is shown for the center tank fuel pump No. 1 (37QA):
(a) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(b) Open the left main landing gear door for access AMM 32-12-00-010-001.
(c) Get access to the center tank fuel pump No. 1, 37QA AMM 28-21-51-000-002.
(d) Before you do more steps make sure that fuel from a leak or spillage does not contaminate the areas (in zones 147 and 195) that follow:
a Repair all the leaks:
b Clean the area of the fuel spillage.
c Clean and dry the fuel pump supply cable and the end connector 37QA-A.
(e) Disconnect the supply cable end connector 37QA-A from the fuel pump receptacle.
1 Make sure that good lighting is available.
Do a visual inspection and look for distortion (pinched or streched) damage (chafed or cut), discoloration, overheating (burnt/melted or arcing) liquid contamination, loose electrical connection or incorrect assembly, of the items that follow:
a If a wire is damaged, the complete section (length) of (each) wire (between the fuel pump connector 37QA-A and the connector 7612VC-A that goes through pressure seal 7611VP) must be replaced AWM 282105.
This is because the wires are located in a fuel and vapour zone ESPM 2031360.
3 If the aircraft structure is damaged, refer to Allowable Damage, P. Block 101, SRM 530000 for the related type of damage in the Table of Contents.
(f) Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the 115VAC three phases will be supplied to the fuel pump connector 37QA-A.
(g) Do a test with a MULTIMETER - STANDARD to make sure that each of the 115VAC three phases are available at the connector 37QA-A ASM 282103.
(h) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the GFI 69QA.
1 On the fuel page of the ECAM System Display, do a check of the center-tank-pump 1 symbol:
(i) If the 115VAC three phase supply voltage measured in step (g) is correct, replace the PUMP-FUEL NO 1, CTR TK [37QA] AMM 28-21-51-000-002 and AMM 28-21-51-400-002.
(j) If the 115VAC three phase supply voltage measured in step (g) is not correct, (no voltage, incorrect voltage or a phase is missing) do all the sub-steps that follow:
1 In the cockpit (right rear) do a visual inspection as specified in step (e)1_ of the items that follow, replace if necessary:
a The C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] at the C/B panel 121VU AWM 930121.
b The connector 2212VC-A and related receptacle at the panel 120VU AWM 930120.
2 Release the front face of the C/B panel 121VU and lower to the open (horizontal) position.
3 Make sure that the C/B-29QA is closed. Use a MULTIMETER - STANDARD and make sure that the 115VAC three phases are available at input and output terminals of the C/B-29QA ASM 282103.
4 If the 115VAC supply to the C/B-29QA, is not available at terminals A1, B1 and C1 trouble shoot the AC supply ASM 245802.
5 If, with the C/B-29QA closed, the 115VAC supply is not available at terminals A2, B2 and C2, replace the C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] .
6 Raise the front face of the C/B panel 121VU to the closed (vertical) position and secure.
7 In the forward avionics bay, remove the front cover of the contactor box 107VU AWM 930107.
8 Do a visual inspection as specified in step (e)1_ and replace, if necessary:
a Make sure that the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] is in the untripped reset condition.
b The connectors 1260VC-A and 1264VC-A and the related receptacles.
9 If the fault has not been identified, remove the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
10 Use a multimeter and make sure that each of the 115VAC three phases are available at the GFI base input sockets (A1, B1, and C1) ASM 282103.
11 If the 115VAC is available, replace the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] with a serviceable item.
a Do the operational test of the GFI 69QA AMM 28-18-00-710-801.
b Go to step 13_.
Do the test as follows:
a Cotinuity test, with a MULTIMETER - STANDARD, of each three phase wire (from end to end) ESPM 2052210.
b Insulation test, with an intrinsically safe 500VDC insulation tester, between each phase wire (pole) and ground ESPM 2052240.
c Insulation test, with an intrinsically safe 500VDC insulation tester, between each phase wire and the other two wires (pole to pole) ESPM 2052240.
d Repair, replace the unserviceable wiring and connectors.
f Install the front cover of the contactor box 107VU.
13 Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the 115VAC three phases will be supplied to the fuel pump connector 37QA-A. ASM 282103.
14 Use a MULTIMETER - STANDARD to do a test, to make sure that each of the 115VAC three phases are available at the connector 37QA-A ASM 282103>.
15 Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
16 If in step 13_ the 115VAC is available at the connector 37QA:
a Install the front cover of the contactor box 107VU.
b Connect the connector 37QA-A to the fuel pump receptacle.
c Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
17 If the 115VAC is not available at the connector 37QA, do a test of the aircraft wiring (three phase supply) between the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the PUMP-FUEL No 1, CTR TK (37QA) connector 37QA-A AWM 282105.
a Continuity test, with an (intrinsically safe) multimeter, of each three phase wire (from end to end) ESPM 2052210.
b Insulation test, with a MEGOHMMETER 200 MOHMS - 500 VDC, 0.001 A MAX, between each phase wire (pole) and ground ESPM 2052240.
c Insulation test, with an (intrinsically safe) 500VDC insulation tester, between each phase wire and the other two wires (pole to pole) ESPM 2052240.
d Repair or replace the unserviceable wiring and connectors.
If a wire (between the connector 7612VC-A and the fuel pump connector 37QA-A, that goes through the pressure seal (bung) 7611VP) is found to be damaged, the complete section (length) of (each) wire must be replaced. This is because the wires are located in a fuel vapour zone ESPM 203136.
e Install the front cover of the contactor box 107VU.
f Connect the fuel pump supply cable end connector 37QA-A to the fuel pump receptacle.
g Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
(4) If the fuel transfers:
(a) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and remove the 28VDC from the pressure switch.
(b) Open the left main landing gear door for access AMM 32-12-00-010-001.
(c) Get access to center tank fuel pump No. 1, pressure switch 39QA AMM 28-21-15-000-003.
(d) Disconnect the free connector 39QA-A from the PRESS SW-FUEL PUMP NO 1, CTR TK (39QA).
(e) Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(f) See if the P/BSW (33QA) FAULT legend is on or off (with the pressure switch disconnected and the P/BSW pushed (in)).
(g) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(h) If in step (f) the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend stays on go to step (l).
(i) If in step (f) the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend goes off:
(k) Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
(l) If the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend stays on, do a check of the aircraft wiring (low pressure lines) ASM 282103 between the:
(n) Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
(1) Do the operational test of the GFI 69QA AMM 28-18-00-710-801.
(a) If there is a fault with the GFI CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] , replace it.
or
(b) If MMEL conditions apply, deactivate the PUMP-FUEL NO 1, CTR TK [37QA] AMM 28-21-00-040-002. (Ref. MMEL 28-21-02 Center Tank Fuel Pump).
(2) If a fuel low pressure indication is shown for the center tank fuel pump No. 1 (37QA):
- do a fuel transfer, AMM 28-21-00-710-007 use the center tank fuel pump No. 1 to do the fuel transfer.
(a) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(b) Open the left main landing gear door for access AMM 32-12-00-010-001.
(c) Get access to the center tank fuel pump No. 1, 37QA AMM 28-21-51-000-002.
(d) Before you do more steps make sure that fuel from a leak or spillage does not contaminate the areas (in zones 147 and 195) that follow:
- the center tank bottom skin adjacent to the left fuel pump 37QA
- the hydraulic compartment below the wing box (center tank) and forward side of the rear bulkhead at FR42
- the rear wall (spar) of the center tank in the left main landing gear bay
- the rear side of the bulkhead at FR 42 below the center tank.
a Repair all the leaks:
b Clean the area of the fuel spillage.
c Clean and dry the fuel pump supply cable and the end connector 37QA-A.
(e) Disconnect the supply cable end connector 37QA-A from the fuel pump receptacle.
1 Make sure that good lighting is available.
Do a visual inspection and look for distortion (pinched or streched) damage (chafed or cut), discoloration, overheating (burnt/melted or arcing) liquid contamination, loose electrical connection or incorrect assembly, of the items that follow:
- the fuel pump receptacle
- the fuel pump supply cable end connector 37QA-A
- the fuel pump supply cable
- the forward and rear sides of the structure of bulkhead FR42 adjacent to the route of the supply cable.
a If a wire is damaged, the complete section (length) of (each) wire (between the fuel pump connector 37QA-A and the connector 7612VC-A that goes through pressure seal 7611VP) must be replaced AWM 282105.
This is because the wires are located in a fuel and vapour zone ESPM 2031360.
3 If the aircraft structure is damaged, refer to Allowable Damage, P. Block 101, SRM 530000 for the related type of damage in the Table of Contents.
(f) Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the 115VAC three phases will be supplied to the fuel pump connector 37QA-A.
(g) Do a test with a MULTIMETER - STANDARD to make sure that each of the 115VAC three phases are available at the connector 37QA-A ASM 282103.
(h) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the GFI 69QA.
1 On the fuel page of the ECAM System Display, do a check of the center-tank-pump 1 symbol:
- If the center-tank-pump 1 symbol is not green, go to step (i).
- If the center-tank-pump 1 symbol is green, do the steps that follow:
NOTE: This is to make sure that the GFI 69QA does not stay in the on position.
3 If necessary, replace the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] . (i) If the 115VAC three phase supply voltage measured in step (g) is correct, replace the PUMP-FUEL NO 1, CTR TK [37QA] AMM 28-21-51-000-002 and AMM 28-21-51-400-002.
(j) If the 115VAC three phase supply voltage measured in step (g) is not correct, (no voltage, incorrect voltage or a phase is missing) do all the sub-steps that follow:
1 In the cockpit (right rear) do a visual inspection as specified in step (e)1_ of the items that follow, replace if necessary:
a The C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] at the C/B panel 121VU AWM 930121.
b The connector 2212VC-A and related receptacle at the panel 120VU AWM 930120.
2 Release the front face of the C/B panel 121VU and lower to the open (horizontal) position.
3 Make sure that the C/B-29QA is closed. Use a MULTIMETER - STANDARD and make sure that the 115VAC three phases are available at input and output terminals of the C/B-29QA ASM 282103.
4 If the 115VAC supply to the C/B-29QA, is not available at terminals A1, B1 and C1 trouble shoot the AC supply ASM 245802.
5 If, with the C/B-29QA closed, the 115VAC supply is not available at terminals A2, B2 and C2, replace the C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] .
6 Raise the front face of the C/B panel 121VU to the closed (vertical) position and secure.
7 In the forward avionics bay, remove the front cover of the contactor box 107VU AWM 930107.
8 Do a visual inspection as specified in step (e)1_ and replace, if necessary:
a Make sure that the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] is in the untripped reset condition.
b The connectors 1260VC-A and 1264VC-A and the related receptacles.
9 If the fault has not been identified, remove the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
10 Use a multimeter and make sure that each of the 115VAC three phases are available at the GFI base input sockets (A1, B1, and C1) ASM 282103.
11 If the 115VAC is available, replace the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] with a serviceable item.
a Do the operational test of the GFI 69QA AMM 28-18-00-710-801.
b Go to step 13_.
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.
CAUTION:
YOU MUST DISCONNECT THE GFI FROM THE AIRCRAFT INSTALLATION BEFORE YOU DO THE INSULATION RESISTANCE TESTS. IF THE GFI IS NOT DISCONNECTED, DAMAGE WILL OCCUR TO THE GFI.
12 If the 115VAC supply to the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] is not available, do a test of the aircraft wiring (three phase supply) between the C/B-FUEL/CTR TK/PUMP1 SPLY [29QA] and the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] ASM 282103. Do the test as follows:
a Cotinuity test, with a MULTIMETER - STANDARD, of each three phase wire (from end to end) ESPM 2052210.
b Insulation test, with an intrinsically safe 500VDC insulation tester, between each phase wire (pole) and ground ESPM 2052240.
c Insulation test, with an intrinsically safe 500VDC insulation tester, between each phase wire and the other two wires (pole to pole) ESPM 2052240.
d Repair, replace the unserviceable wiring and connectors.
CAUTION:
DO NOT USE IN-LINE SPLICES TO REPAIR SECTIONS OF ELECTRICAL CABLE THAT ARE BEHIND A FAIRING OR IN A CONDUIT.
THIS WILL MAKE SURE THAT IT IS POSSIBLE TO SEE THE REPAIR FOR AN INSPECTION (REF. ESPM 20-53-29).
e Install the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and make sure that the GFI is in the untripped reset condition. f Install the front cover of the contactor box 107VU.
13 Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the 115VAC three phases will be supplied to the fuel pump connector 37QA-A. ASM 282103.
14 Use a MULTIMETER - STANDARD to do a test, to make sure that each of the 115VAC three phases are available at the connector 37QA-A ASM 282103>.
15 Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
16 If in step 13_ the 115VAC is available at the connector 37QA:
a Install the front cover of the contactor box 107VU.
b Connect the connector 37QA-A to the fuel pump receptacle.
c Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
17 If the 115VAC is not available at the connector 37QA, do a test of the aircraft wiring (three phase supply) between the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and the PUMP-FUEL No 1, CTR TK (37QA) connector 37QA-A AWM 282105.
NOTE: The aircraft wiring is divided into two sections (lengths) by the connector 7612VC. The section of the power supply cable between 7612VC-A and the fuel pump connector 37QA-A is located in a fuel and vapour zone ESPM 2031360.
Do the test as follows: a Continuity test, with an (intrinsically safe) multimeter, of each three phase wire (from end to end) ESPM 2052210.
b Insulation test, with a MEGOHMMETER 200 MOHMS - 500 VDC, 0.001 A MAX, between each phase wire (pole) and ground ESPM 2052240.
c Insulation test, with an (intrinsically safe) 500VDC insulation tester, between each phase wire and the other two wires (pole to pole) ESPM 2052240.
d Repair or replace the unserviceable wiring and connectors.
If a wire (between the connector 7612VC-A and the fuel pump connector 37QA-A, that goes through the pressure seal (bung) 7611VP) is found to be damaged, the complete section (length) of (each) wire must be replaced. This is because the wires are located in a fuel vapour zone ESPM 203136.
e Install the front cover of the contactor box 107VU.
f Connect the fuel pump supply cable end connector 37QA-A to the fuel pump receptacle.
g Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
(4) If the fuel transfers:
(a) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] and remove the 28VDC from the pressure switch.
(b) Open the left main landing gear door for access AMM 32-12-00-010-001.
(c) Get access to center tank fuel pump No. 1, pressure switch 39QA AMM 28-21-15-000-003.
(d) Disconnect the free connector 39QA-A from the PRESS SW-FUEL PUMP NO 1, CTR TK (39QA).
(e) Set the CTR TK PUMP 1 P/BSW (33QA) to ON (push in). This will energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(f) See if the P/BSW (33QA) FAULT legend is on or off (with the pressure switch disconnected and the P/BSW pushed (in)).
(g) Set the CTR TK PUMP 1 P/BSW (33QA) to OFF (release out). This will de-energize the CNTOR-GFI CTR TK PUMP 1 SUPPLY [69QA] .
(h) If in step (f) the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend stays on go to step (l).
(i) If in step (f) the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend goes off:
- do a check of, and replace if necessary, the PRESS SW-FUEL PUMP NO 1, CTR TK [39QA] AMM 28-21-15-000-003 and AMM 28-21-15-400-001.
NOTE: The fuel-pump fuel pressure can be measured at the safety valve outlet using an 99A28404000000 ADAPTOR-SEQUENCE VALVE. This can be installed in place of the pressure switch 39QA AMM 28-21-45-400-003.
(j) If the fault continues, or if no fuel pressure is shown on the gage of the ADAPTOR - SEQUENCE VALVE, make sure that these components are in the correct condition: - the pressure switch safety valve
- the
pressure switch plug (banjo adaptor attachment bolt) - the pressure switch fuel supply pipe-line between the fuel pump canister 84QM and the pressure switch 39QA .
NOTE: The first section of the fuel supply pipe-line to the pressure switch 39QA is also the primary supply to the center tank (left side) water scavenge jet pump 89QM.
1 Repair/replace the components that are unserviceable. (k) Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.
(l) If the P/BSW-FUEL/CTR TK/PUMP 1 (33QA) FAULT legend stays on, do a check of the aircraft wiring (low pressure lines) ASM 282103 between the:
- pressure switch connector 39QA-A, pin C and the relay-41QA, terminal 1
- pressure switch connector 39QA-A, pin C and the FLSCU-1 rack connector 7QJ-AA, terminal 12C
- pressure switch connector 39QA-A, pin C and the SDAC-1 rack connector 1WV1-AA, terminal 13F
- pressure switch connector 39QA-A, pin C and the SDAC-2 rack connector 1WV2-AA, terminal 13F
- relay-41QA, terminal A and the relay-49QA, terminal 1
- relay-49QA, terminal A and the BOARD-ANN LT TEST & INTFC connector 18LP-A, terminal 31
- BOARD-ANN LT TEST & INTFC connector 18LP-A, terminal 17 and the P/BSW-FUEL/CTR TK/PUMP 1 connector 33QA-A, terminal 7.
NOTE: A short circuit to ground on one of these lines will cause:
(m) Repair the unserviceable wiring and connectors. - a false LO PR warning to be generated within the FWC
- the FAULT legend/lamp to come on incorrectly.
- BOARD-ANN LT TEST & INTFC (18LP)
- FLSCU-1 (7QJ)
- SDAC-1 (1WV1)/SDAC-2 (1WV2)
- RELAY-CTR TK AUTO CONTROL, PUMP 1 (41QA)
- RELAY-CTR TK FAULT INHIBIT, PUMP 1 (49QA)
- P/BSW-FUEL PUMP 1 (33QA).
(n) Do the Functional Test of the Center Tank Fuel Control (Manual Mode) AMM 28-21-00-720-001.