LGCIU - EFCS Reports Loss of Data from LGCIU 2 Bus 2

TASK 32-31-00-810-845-A
LGCIU - EFCS Reports Loss of Data from LGCIU 2 Bus 2

1. Possible Causes

LGCIU-2 [5GA2]
SEC-1 [1CE1]
aircraft wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AWM 279251
AMM 27-94-34-000-001	Removal of the SEC
AMM 27-94-34-400-001	Installation of the SEC
AMM 27-96-00-740-001	BITE Test of the EFCS (Ground Scanning)
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
AWM 326106

3. Fault Confirmation
Subtask 32-31-00-710-062-A

A. Test
(1) Do a check of the Post Flight Report (PFR) to see if other systems have also identified the same fault.

NOTE: If other systems also identify the same loss of data, the fault will be in the LGCIU, or the bus wiring which is the same for all those systems. If only one system has identified the loss of data, the fault will be in that system or the wiring which is applicable to that system only.

(2) Do the BITE test of the EFCS (Ground Scanning) AMM 27-96-00-740-001

if the message NO FAULTS RECORDED is shown, no other maintenance work is necessary
if the message LGCIU2 BUS2 is shown do the fault isolation procedure in Para. 4.A.

4. Fault Isolation
Subtask 32-31-00-810-096-A

A. Procedure
(1) Interchange the LGCIU-2 with the LGCIU-1 AMM 32-31-71-000-001, AMM 32-31-71-400-001.
(a) Do the test in Para. 3.A.(2):

if the fault continues, do step (3)
if the fault goes, do the next step.

(2) Install the LGCIUs in their initial locations and replace the LGCIU-2 [5GA2] .
(a) Do the test in Para. 3.A.(2):

if the fault continues and has been identified by other systems, do step (4)
if the fault continues and has been identified by the EFCS only, do the next step.

(3) Replace the SEC-1 [1CE1] , AMM 27-94-34-000-001 and AMM 27-94-34-400-001.
(a) Do the test in Para. 3.A.(2):

if the fault continues, do the next step.

(4) Do a check and repair as necessary the LGCIU-2 BUS 2 aircraft wiring between the LGCIU-2 ARINC connector tray and the SEC-1 AWM 326106 and AWM 279251.
(5) Do the test in Para. 3.A.(2).

[Rev.8 from Aug 2018] 2026.04.04 04:31:23 UTC