DOC AIRBUS | TSM A320FFailure of the ENG START Discrete Output on EIU 1
1. Possible Causes
· RELAY-ENGINE START ( 17HB )
· EIU-1 ( 1KS1 )
· wiring
· CONT-AIR COND SYSTEM 1 ( 47HH )
· CONT-AIR COND SYSTEM 2 ( 57HH )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 21-61-34-000-002 Removal of the Air-Conditioning System Controller
Ref. AMM 21-61-34-400-002 Installation of the Air-Conditioning System Controller
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 73-25-00-710-092-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 73-25-00-810-071-A
A. If the operational test gives the maintenance message CHECK 17HB RELAY CIRCUIT OR EIU-1:
· Replace the RELAY-ENGINE START ( 17HB ) .
(1) If the fault continues:
· Replace the EIU-1 ( 1KS1 ) , Ref. AMM 73-25-34-000-041 and Ref. AMM 73-25-34-400-041 .
(2) If the fault continues:
· Do a check and repair the wiring between the pin AB/1J of EIU-1 (1KS1) and the pin A/Z of the
engine start relay (17HB) Ref. ASM 73-25-09.
Subtask 73-25-00-810-071-B
A. If the operational test gives the maintenance message CHECK 17HB RELAY CIRCUIT OR EIU-1:
· Replace the CONT-AIR COND SYSTEM 1 ( 47HH ) and CONT-AIR COND SYSTEM 2 ( 57HH ) Ref.
AMM 21-61-34-000-002 and Ref. AMM 21-61-34-400-002 .
NOTE: 47HH and 57HH are part of the new AIR COND system and are the substitute for the 17HB relay
circuit.
(1) If the fault continues:
· Replace the EIU-1 ( 1KS1 ) , Ref. AMM 73-25-34-000-041 and Ref. AMM 73-25-34-400-041 .
(2) If the fault continues:
Do a check and repair the wiring Ref. ASM 73-25-09 between:
· Pin AB/1J of the EIU-1 (1KS1) and pin AB/1k of the ACSC (47HH)
· Pin AB/1J of the EIU-1 (1KS1) and pin AB/1K of the ACSC (57HH).
Subtask 73-25-00-710-093-A
B. Do the test given in Para. 3. [Rev.6 from Feb 2017] 2026.04.04 04:36:22 UTC