Output Bus E Fault on EIU-2

TASK 73-25-00-810-A49-A
Output Bus E Fault on EIU-2

1. Possible Causes

EIU-2 [1KS2]
HARNESS-FAN, WF02 [4218KS]
harness
[4000KS]

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

REFERENCE	QTY	DESIGNATION
No specific	1	MULTIMETER - STANDARD
No specific	1	PLIERS - JAWED, SOFT

B. Referenced Information

REFERENCE	DESIGNATION
AMM 70-70-00-910-803	SPOP 6 - Cleaning of the Contact Points and Wiring Harnesses
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 73-21-01-000-801	Removal of the Electronic Engine Control (EEC)
AMM 73-21-01-400-801	Installation of the Electronic Engine Control (EEC)
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)
AWM 732524
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)

3. Fault Confirmation
Subtask 73-25-00-710-486-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 73-25-00-810-330-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Replace EIU-2 [1KS2] 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:
(a) Open the fan cowl doors AMM 71-13-00-010-802 of engine 2.
(b) Examine the WF02 (4218KS) harness, connector P1 (4000KS-P1) - EEC (4000KS) and connector P402 (402VC-A) - pylon junction box, for problems which are possible between the EEC (4000KS) and the pylon junction box.
1 Inspect for harness damage.
2 Inspect for loose or damaged connectors.

NOTE: Loose connectors must be disconnected and examined for further wear or damage.

3 If a problem is found with the harness or connectors:
a Replace the HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
b Do the test given in Para. 3.
(4) If no problems are found with the harness or the fault continues, use a PLIERS - JAWED, SOFT to disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box.
(a) Examine the pins and sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Clean the contacts with contact cleaner and clean cloth per SPOP 6. Blow dry with air (at less than 30 psi) across connector face AMM 70-70-00-910-803.
(c) Reconnect the electrical connector P1 (4000KS-P1) to the EEC (4000KS) and connector P402 (402VC-A) to the pylon junction box.
(d) Do the test given in Para. 3.
(5) If the fault continues:
(a) Disconnect the electrical connector P1 (4000KS-P1) from the EEC (4000KS) and connector P402 (402VC-A) from the pylon junction box. Use a MULTIMETER - STANDARD to test the EIU circuit in the harness. Refer to Table 1. Look for:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).

NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.

Table 1: EEC to Pylon Junction Box EIU Circuit Channel A Connector Contacts

WF02 (4218KS) Harness P1 (4000KS-P1) EEC (4000KS) Connector Contacts	WF02 (4218KS) Harness P402 (402VC-A) Pylon Junction Box Connector Contacts
GG	4
HH	12

(b) If a problem is found with the harness or connectors:
1 Replace the HARNESS-FAN, WF02 [4218KS] AMM 73-21-62-000-802 and AMM 73-21-62-400-802.
2 Do the test given in Para. 3.
(6) If no problems are found with the harness or the fault continues, do a check of the EIU circuit in the aircraft wiring.
(a) Remove the EIU-2 AMM 73-25-34-000-802.
(b) Test the aircraft harness:
1 Wire-to-wire shorts
2 Shorts to ground
3 Continuity (less than 5 ohms resistance).

NOTE: Short to ground is found when the resistance is less than 100 000 (100K) ohms.

NOTE: For continuity, add a jumper between P402 (402VC-A) pins 4 and 12 and check continuity between EIU connector AB pins 5A and 5C.

Table 2: Pylon Junction Box to EIU Connector Contact (Channel A)

P402 (402VC-A) Pylon Junction Box Connector Contacts	On Rack Side EIU Connector Contact
4	5A
12	5C

(c) If a problem is found with the harness or connector, repair or replace the harness AWM 732524.
(d) Do the test given in Para. 3.
(7) If the fault continues:
(a) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-091-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.
(a) Close the fan cowl doors AMM 71-13-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:36:29 UTC