LGCIU - Loss of Data by the SEC,DMC,FWC,DMU,FAC or SFCC from LGCIU 1 or LGCIU 2

TASK 32-31-00-810-844-A
LGCIU - Loss of Data by the SEC,DMC,FWC,DMU,FAC or SFCC from LGCIU 1 or LGCIU 2

1. Possible Causes

LGCIU-1 [5GA1]
LGCIU-2 [5GA2]
aircraft wiring

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-31-71-000-001	Removal of the LGCIU
AMM 32-31-71-400-001	Installation of the LGCIU
ASM 326104

3. Fault Confirmation
Subtask 32-31-00-710-061-A

A. Test
(1) Select MCDU MENU mode and set the CFDS menu, then access the A/C CURRENT STATUS page.
(2) Do a check of the STATUS report and look for an LGCIU 1 (2) fault from the SEC, DMC, FWC, DMU, FAC and SFFC:

If only one of the units reports a fault, do the trouble shooting procedure related to the maintenance message applicable to the unit that reported the fault
If more than one of these units report a fault, do the Fault Isolation procedure in Para. 4.

NOTE: The ATA references for the related sytems are as follows:

SEC (27-95-00)
DMC (31-63-00)
FWC (31-53-00)
DMU (31-36-00)
FAC (22-66-00)
SFCC (27-51-00)

4. Fault Isolation
Subtask 32-31-00-810-095-A

A. Procedure

NOTE: This fault isolation procedure is for an LGCIU loss of data fault, reported by other units connected to the LGCIU by an ARINC data-bus.

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

if the fault stays in the LGCIU system shown on the PFR, go to step (5)
if the fault moves to the opposite LGCIU system, do the next step

(3) Replace the LGCIU-1 [5GA1] or LGCIU-2 [5GA2] , in the opposite system to that shown on the PFR.
(4) Do the test in Para. 3.A:

if the fault continues, do the next step.

(5) Do a check of the aircraft wiring ASM 326104 related to the ARINC connector of the LGCIU system shown on the PFR.
(6) Do the test in para 3.A.

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