EIU-1 Relay Fault for PHMU Power Supply

TASK 73-25-00-810-A10-A
EIU-1 Relay Fault for PHMU Power Supply

1. Possible Causes

EIU-1 [1KS1]
HARNESS-FAN, WF02 [4218KS]

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

REFERENCE	QTY	DESIGNATION
No specific	1	PLIERS - JAWED, SOFT
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Referenced Information

REFERENCE	DESIGNATION
AMM 71-13-00-010-802	Opening of the Fan Cowl Doors
AMM 71-13-00-410-802	Closing of the Fan Cowl Doors
AMM 73-21-62-000-802	Removal of the EEC Wiring Harness (WF02)
AMM 73-21-62-400-802	Installation of the EEC Wiring Harness (WF02)
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)
AWM 732556

3. Fault Confirmation
Subtask 73-25-00-710-445-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 73-25-00-810-271-A ** ON A/C NOT FOR ALL

A. Check for EIU-1 fault
(1) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(a) Do the test given in Para. 3.
(2) If the fault continues:
(a) Go to the Para. 4.B.

Subtask 73-25-00-865-064-A ** ON A/C NOT FOR ALL

B. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENG 1)
121VU	PHMU/ENG1	95KS1	P44

Subtask 73-25-00-810-272-A ** ON A/C NOT FOR ALL

C. Check for harness fault
(1) Open the fan cowl doors AMM 71-13-00-010-802.
(2) Disconnect connector (402VC1-A).
(a) Inspect for pins alignment.
(b) Repair as necessary.
1 Do the test given in Para. 3.
(3) If alignment is correct or fault continues, check for 28 VDC to pins 26 of connector (402VC1) AWM 732556.
(a) If there is 28 VDC at pin, repair aircraft wiring between connector (402VC1) and EIU-1 AWM 732556.
(b) If there is no 28 VDC at pin, use a PLIERS - JAWED, SOFT to disconnect connector P9 at PHMU (4609KS).
1 Inspect for pins alignment.
2 Repair as necessary.
a Do the test given in Para. 3.
(c) If alignment is correct or fault continues:
1 Replace HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
a Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-068-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.
(2) Close the fan cowl doors AMM 71-13-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:36:26 UTC