APU AUTO SHUT DOWN - Shutdown in conjunction with Fuel Low Pressure (131-9(A))

TASK 49-00-81-810-884-A
APU AUTO SHUT DOWN - Shutdown in conjunction with Fuel Low Pressure (131-9(A))

1. Possible Causes

FUEL PRESSURE SHOWS LOW DURING APU RUN
air in the fuel

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 28-22-00-810-801-A	APU Fuel System - Low Pressure
AMM 28-22-00-710-001	Operational Test of the APU Fuel-Pump System on Ground to Purge the Fuel Line
AMM 49-00-00-860-008	APU Start by External Power

3. Fault Confirmation
Subtask 49-00-81-710-218-A ** ON A/C NOT FOR ALL

A. Read-out of ECB Trouble-Shooting Data
(1) Put the APU MASTER SW to the ON position.
(2) Get access to the APU SHUTDOWN report.
(3) Push the '>' adjacent to LRU DATA:

the MCDU menu shows
FUEL PRESSURE SHOWS LOW DURING APU RUN

(4) Purge the APU fuel-line to make sure that there is no air in the fuel AMM 28-22-00-710-001 .
(5) Start the APU and apply Bleed Air for 20 seconds, minimum AMM 49-00-00-860-008.

4. Fault Isolation
Subtask 49-00-81-810-149-A ** ON A/C NOT FOR ALL

A. If an APU auto shutdown occurs during the APU operation and the APU SHUTDOWN report gives the maintenance message:

NO ACCELERATION (or) UNDERSPEED (or) NO FLAME
LOW FUEL PRESSURE

associated with the Fault Code Number (FCN) 100

do the trouble shooting of the APU fuel system - low pressure (Ref. TSM TASK 28-22-00-810-801).

Subtask 49-00-81-710-219-A ** ON A/C NOT FOR ALL

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:37 UTC