EIU-1 Fault to Supply DCV A and B

TASK 73-25-00-810-A30-A
EIU-1 Fault to Supply DCV A and B

1. Possible Causes

EIU-1 [1KS1]
HARNESS - PYLON T/R [4130KS]
EEC WIRING HARNESS WF06 [4089KS]
EEC WIRING HARNESS WF07 [4093KS]

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 73-21-66-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (WF06)
AMM 73-21-66-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (WF06)
AMM 73-21-67-000-801	Removal of the Electronic Engine Control (EEC) Wiring Harness (WF07)
AMM 73-21-67-400-801	Installation of the Electronic Engine Control (EEC) Wiring Harness (WF07)
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 78-31-61-000-813	Removal of the Pylon TRAS Monitoring Harness
AMM 78-31-61-400-813	Installation of the Pylon TRAS Monitoring Harness
AWM 783606

3. Fault Confirmation
Subtask 73-25-00-710-467-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 73-25-00-810-303-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Replace EIU-1 [1KS1] AMM 73-25-34-000-802 and AMM 73-25-34-400-802.
(2) Do the test given in Para. 3.
(3) If the fault continues, troubleshoot as follows:

Subtask 73-25-00-865-082-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	DCV B/ENG1 PWR SPLY	103KS1	K44
121VU	DCV A/ENG1 PWR SPLY	102KS1	K42

Subtask 73-25-00-810-304-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) Use a PLIERS - JAWED, SOFT to disconnect connectors (P491) and (P494) and check for 28 VDC at pin 5 of both connectors (491VC1) and (494VC1).
(3) If there is 28 VDC at pin 5 of connectors (491VC1):
(a) Disconnect connector (445VC1-A) and check for 28 VDC at pins 6 of connector (445VC1).
(b) If there is 28 VDC at pin 6:
1 Repair or replace aircraft wiring AWM 783606.
(c) If there is not 28 VDC at pin 6:
1 Replace HARNESS - PYLON T/R [4130KS] AMM 78-31-61-000-813 and AMM 78-31-61-400-813.
(4) If there is not 28 VDC at pin 5 of connector (491VC1):
(a) Replace EEC WIRING HARNESS WF06 [4089KS] AMM 73-21-66-000-802 and AMM 73-21-66-400-802.
(5) If there is 28 VDC at pin 5 of connector (494VC1):
(a) Disconnect connector (445VC1-A) and check for 28 VDC at pins 4 of connector (445VC1).
1 If there is 28 VDC at pin 4:
a Repair or replace aircraft wiring AWM 783606.
2 If there is not 28 VDC at pin 4:
a Replace HARNESS - PYLON T/R [4130KS] AMM 78-31-61-000-813 and AMM 78-31-61-400-813.
(6) If there is not 28 VDC at pin 5 of connector (494VC1):
(a) Replace EEC WIRING HARNESS WF07 [4093KS] AMM 73-21-67-000-801 and AMM 73-21-67-400-801.
(7) If necessary, connect connectors (P491), (P494) and (445VC1).
(8) Close the circuits breakers. Refer to the Para. 5.B.
(9) Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-074-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.

Subtask 73-25-00-865-083-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 4020KM1 (POWER PLANTDEMOUNTABLE, ENG 1)
121VU	DCV B/ENG1 PWR SPLY	103KS1	K44
121VU	DCV A/ENG1 PWR SPLY	102KS1	K42

[Rev.8 from Aug 2018] 2026.04.04 04:36:28 UTC