N2 not Below Idle Fault on EIU-1

TASK 73-25-00-810-A99-A
N2 not Below Idle Fault on EIU-1

1. Possible Causes

RELAY-N2 SPEED CONDTN (2708GJ)
wiring
EIU-1 [1KS1]
XCVR-RA, 1 [2SA1]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AWM 291205
AWM 344201
AMM 34-42-33-000-001	Removal of the Radio Altimeter Transceiver
AMM 34-42-33-400-001	Installation of the Radio Altimeter Transceiver
AWM 732505
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 73-25-00-710-538-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 73-25-00-810-400-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) On RELAY BOX (103VU):
(a) Replace RELAY-N2 SPEED CONDTN (2708GJ) AWM 291205.
(b) Do the test given in Para. 3.
(2) If the fault continues:
(a) Remove the XCVR (2SA1) AMM 34-42-33-000-001.
(3) On RELAY BOX (103VU), remove the relay (2708GJ).
(4) On MCDU, simulate the Discrete Output (DSO) 12:
(a) Push the adjacent button to DSO 12 to have the status equal to 1 AMM 73-25-34-860-803.
(b) At XCVR (2SA1) rack connector (AB), do a check for ground at contact 6K.
(c) At relay (2708GJ) socket, do a check for ground at contact Z.
(d) Stop the simulation of DSO 12 AMM 73-25-34-860-803.
(5) If there is no ground, do a check of wiring for continuity (less than 5 ohms resistance) and short to ground:
(a) If there is no ground at both contacts, do a check of wiring between EIU-1 (1KS1) rack contact 2F and (1853VT) on SHELF (85VU) AWM 732505.
(b) If there is no ground at contact of XCVR (2SA1) rack, do a check of wiring between contact 6K of XCVR (2SA1) rack and (1853VT) AWM 344201.
(c) If there is no ground at relay (2708GJ) socket, do a check of wiring between contact Z and (1853VT) AWM 291205.
(d) If you find damage, repair or replace wiring .
(e) If you find no damage:
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.
(6) If there is ground at all contacts:
(a) Replace XCVR-RA, 1 [2SA1] AMM 34-42-33-000-001 and AMM 34-42-33-400-001.
(b) Install the relay (2708GJ).
(c) Do the test given in Para. 3.

5. Close-up
Subtask 73-25-00-860-162-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