Fuel Pumps - Center Tank Pumps 1 and 2 System Malfunction

TASK 28-21-00-810-826-A
Fuel Pumps - Center Tank Pumps 1 and 2 System Malfunction

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

1. Possible Causes

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

3. Fault Confirmation
Subtask 28-21-00-710-071-B ** ON A/C NOT FOR ALL

A. Test
(1) Do the applicable instruction that follows:

If the center-tank pump fault message does not occur frequently when the center-tank pumps are set to AUTO on the ground, (shown in flight phase 02 on the PFR) or in flight (flight phase 06). When the fuel QTY is <250kg in the center tank, this is a symptom of a spurious defect. No further maintenance action is necessary.
If the center-tank pump fault message occurs each flight, when the center-tank pumps are set to AUTO with the fuel QTY <250kg. This is a symptom of a defect in the Auto control circuit. Do the applicable troubleshooting in Para 4.
If the center-tank pump fault message occurs at a different time (in MANUAL or AUTO) when the center-tank fuel QTY is >250kg. Do the applicable troubleshooting in Para 4.

NOTE: For more data Ref. TFU 28.21.00.039 Center Tank Low Pressure Warnings.

4. Fault Isolation
Subtask 28-21-00-810-071-B ** ON A/C NOT FOR ALL

A. Procedure
(1) If a fuel low pressure indication is given for the two center tank fuel pumps, do the tasks that follow:

[Rev.8 from Aug 2018] 2026.04.04 04:28:37 UTC