Failure of the APU BOOST Discrete Output on EIU 1

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1. Possible Causes
· wiring from the EIU 1 (1KS1) to the ECB (59KD)
· EIU-1 ( 1KS1 )
· ELECTRONIC CONTROL BOX ( 59KD )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 49-61-34-000-001 Removal of the Electronic Control Box (ECB) (GTCP 36-300)
Ref. AMM 49-61-34-400-001 Installation of the Electronic Control Box (ECB) (GTCP 36-300)
Ref. ASM 73-25-09
Ref. AMM 73-25-34-000-041 Removal of the Engine Interface Unit (EIU)
Ref. AMM 73-25-34-400-041 Installation of the Engine Interface Unit (EIU)
Ref. AMM 73-25-34-710-042 Operational Test of the EIU with the CFDS
3. Fault Confirmation
Subtask 73-25-00-710-084-A
A. Test
(1) Do the operational test of the EIU 1 with the CFDS Ref. AMM 73-25-34-710-042 .
4. Fault Isolation
Subtask 73-25-00-810-067-A
A. If the operational test gives the maintenance message CHECK ECB (59KD)/EIU1 CIRCUIT OR EIU1:
· do a check of the wiring from the EIU 1 (1KS1) to the ECB (59KD) pin AB/1C to pin AB/E5 Ref. ASM
73-25-09.
(1) If there is no continuity:
· repair the above wiring.
(2) If there is continuity:
· replace the EIU-1 ( 1KS1 ) , Ref. AMM 73-25-34-000-041 and Ref. AMM 73-25-34-400-041 .
(a) If the fault continues:
· replace the ELECTRONIC CONTROL BOX ( 59KD ) , Ref. AMM 49-61-34-000-001 and Ref.
AMM 49-61-34-400-001 .
Subtask 73-25-00-710-085-A
B. Do the test given in Para. 3. [Rev.6 from Feb 2017] 2026.04.04 04:36:21 UTC