APU Boost Command 1 Fault on EIU-1

TASK 73-25-00-810-B19-A
APU Boost Command 1 Fault on EIU-1

1. Possible Causes

[59KD]
wiring
EIU-1 [1KS1]

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

REFERENCE	QTY	DESIGNATION
No specific	1	MULTIMETER - STANDARD

B. Referenced Information

REFERENCE	DESIGNATION
AWM 496103
AMM 49-61-34-000-001	Removal of the Electronic Control Box (ECB) (GTCP 36-300)
AMM 49-61-34-000-002	Removal of the Electronic Control Box (ECB) (APS 3200)
AMM 49-61-34-000-003	Removal of the Electronic Control Box (ECB) (131-9(A))
AMM 49-61-34-400-001	Installation of the Electronic Control Box (ECB) (GTCP 36-300)
AMM 49-61-34-400-002	Installation of the Electronic Control Box (ECB) (APS 3200)
AMM 49-61-34-400-003	Installation of the Electronic Control Box (ECB) (131-9(A))
AWM 732505
AMM 73-25-34-000-802	Removal of the Engine Interface Unit (EIU)
AMM 73-25-34-400-802	Installation of the Engine Interface Unit (EIU)
AMM 73-25-34-710-802	Operational Test of the Engine Interface Unit (EIU) with the Centralized Fault Display System (CFDS)

3. Fault Confirmation
Subtask 73-25-00-710-558-A ** ON A/C NOT FOR ALL

A. Do the operational test of the Engine Interface Unit (EIU) (1KS1) with the Centralized Fault Display System (CFDS) to confirm this fault AMM 73-25-34-710-802.

4. Fault Isolation
Subtask 73-25-00-810-436-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Do the operational test of the EIU-2 (1KS2) with the CFDS to confirm this fault AMM 73-25-34-710-802.
(2) If the same fault for Auxiliary Power Unit (APU) boost command 1 is confirmed also for EIU-2 (1KS2), use a MULTIMETER - STANDARD to do a check of the common wiring from the two EIUs to the Electronic Control Box (ECB) (59KD).
(a) Remove [59KD] :

If ECB (APU GTCP 36-300) is installed AMM 49-61-34-000-001
If ECB (APU APS 3200) is installed AMM 49-61-34-000-002
If ECB (APU 131-9(A)) is installed AMM 49-61-34-000-003.

(b) Do a check for continuity and short to ground between contacts T of terminal block 1853VT and 5E of ECB (59KD) AWM 496103.
(c) If a problem is found, repair or replace wiring AWM 496103.
(d) If no problem is found:
1 Replace [59KD] :

If ECB (APU GTCP 36-300) is installed AMM 49-61-34-400-001
If ECB (APU APS 3200) is installed AMM 49-61-34-400-002
If ECB (APU 131-9(A)) is installed AMM 49-61-34-400-003.

(e) Do the test given in Para. 3.
(3) If the same fault for APU boost command 1 is not confirmed for EIU-2 (1KS2) or if the fault continues, do a check of the wiring from the EIU-1 (1KS1) to the terminal block (1853VT):
(a) Remove EIU-1 [1KS1] AMM 73-25-34-000-802.
(b) Do a check for continuity and short to ground between contacts R of terminal block 1853VT and 1C of EIU-1 (1KS1) AWM 732505.
(c) If a problem is found, repair or replace wiring AWM 732505.
(d) If no problem is found:
1 Replace EIU-1 [1KS1] AMM 73-25-34-400-802.
(e) Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-164-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.

[Rev.8 from Aug 2018] 2026.04.04 04:36:50 UTC