APU AUTO SHUTDOWN - NO ACCELERATION, IGV Position disagrees with Command (131-9(A))

TASK 49-00-81-810-840-A
APU AUTO SHUTDOWN - NO ACCELERATION, IGV Position disagrees with Command (131-9(A))

1. Possible Causes

IGV POSITION DISAGREES WITH COMMAND
damage/leakage of the fuel supply and return lines
IGV ACTUATOR (P21)
APU [4005KM]
damage of the IGV linkage
damage/contamination of the electrical connector P21
aircraft wiring
ELECTRONIC CONTROL BOX [59KD]
IGV ACTUATOR (8014KM)

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	MULTIMETER - STANDARD

B. Referenced Information

REFERENCE	DESIGNATION
AMM 49-00-00-860-008	APU Start by External Power
AMM 49-11-11-000-004	Removal of the Power Plant (APU) (131-9(A))
AMM 49-11-11-400-004	Installation of the Power Plant (APU) (131-9(A))
AMM 49-23-51-000-004	Removal of the Inlet Guide Vane - Actuator (131-9(A))
AMM 49-23-51-400-004	Installation of the Inlet Guide Vane - Actuator (131-9(A))
ASM 496104
AMM 49-61-34-000-003	Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-003	Installation of the Electronic Control Box (ECB) (131-9(A))

3. Fault Confirmation
Subtask 49-00-81-710-168-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
IGV POSITION DISAGREES WITH COMMAND

(4) Start the APU and apply Bleed Air for 20 seconds, minimum AMM 49-00-00-860-008.

4. Fault Isolation
Subtask 49-00-81-810-117-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
CHECK IGV ASSEMBLY/IGV ACTUATOR P21

associated with Fault Code Number (FCN) 83

do a check for damage/leakage of the fuel supply and return lines of the IGV ACTUATOR.

(1) If there is damage/leakage in the fuel supply and return lines:

do a repair

(2) If the fuel supply and return lines are OK:

remove the IGV ACTUATOR (P21) from the APU [4005KM] AMM 49-23-51-000-004.
do a check for damage of the IGV linkage :
. make sure that the IGV has a travel range of 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm).
. measure the force of the IGV movement.

(a) If a force less than 20 lbf (8.8964 daN) is necessary to move the IGVs, the IGV linkage is OK:

do a check for damage/contamination of the electrical connector P21 of the IGV ACTUATOR (P21).

1 If the electrical connector P21 is damaged/contaminated:

do a repair/cleaning.

2 If the electrical connector P21 is OK:

use a MULTIMETER - STANDARD to do the resistance a check across pin 4 and pin 10 of the IGV ACTUATOR (P21).

a If the resistance value is < 100 kOhms:

replace the IGV ACTUATOR (P21) AMM 49-23-51-400-004.

b If the resistance value is > 100 kOhms:

do a check of the aircraft wiring from the ECB (59KD) AB/G8 to the IGV ACTUATOR (P21) P21/4 ASM 496104.

c If the fault continues:

replace the ELECTRONIC CONTROL BOX [59KD] AMM 49-61-34-000-003 and AMM 49-61-34-400-003.

(b) If a force more than 20 lbf (8.8964 daN) is necessary to move the IGVs or the travel range is different than 1 -0.01 in. or +0.01 in. (25.400 -0.254 mm or +0.254 mm), the IGV linkage is damaged and/or does not move freely:

replace the APU [4005KM] AMM 49-11-11-000-004 and AMM 49-11-11-400-004.

Subtask 49-00-81-810-117-B ** 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
CHECK IGV ASSEMBLY/IGV ACTUATOR (8014KM)

associated with Fault Code Number (FCN) 83

do a check for damage/leakage of the fuel supply and return lines of the IGV ACTUATOR (8014KM)