HPSOV Closed Fault on EIU-1

TASK 73-25-00-810-A91-A
HPSOV Closed Fault on EIU-1

1. Possible Causes

wiring
EIU-1 [1KS1]
CONT-AIR COND SYSTEM 1 [47HH]

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
AMM 21-61-34-000-002	Removal of the Air-Conditioning System Controller
AMM 21-61-34-400-002	Installation of the Air-Conditioning System Controller
AWM 216309
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)
AMM 73-25-34-860-803	Engine Interface Unit (EIU) DISCRETE OUTPUTS Simulation

3. Fault Confirmation
Subtask 73-25-00-710-530-A ** ON A/C NOT FOR ALL

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

4. Fault Isolation
Subtask 73-25-00-810-392-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Remove the air-conditioning system controller (47HH) AMM 21-61-34-000-002.
(2) On the MCDU, simulate the Discrete Output (DSO) 9:
(a) Push the adjacent button to DSO 9 to have the status equal to 1 AMM 73-25-34-860-803.
(b) At controller rack connector (AB), use a MULTIMETER - STANDARD to do a check for ground at contact 1G AWM 216309.
1 Stop the simulation of DSO 9 AMM 73-25-34-860-803.
(3) If there is no ground, do a check of wiring between contact 1G and contact 1E at EIU-1 (1KS1) AWM 216309 for:
(a) Continuity (less than 5 ohms resistance)
(b) Short to ground.
1 If you find damage, repair or replace wiring AWM 216309.
2 If you find no damage:
a Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
3 Install the air-conditioning system controller (47HH) AMM 21-61-34-400-002.
4 Do the test given in Para. 3.
(4) If there is ground at contact 1G or if the fault continues:
(a) Replace CONT-AIR COND SYSTEM 1 [47HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(b) Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-146-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 04:36:48 UTC