Loss of Data Communication to Lav

TASK 38-31-00-810-836-A
Loss of Data Communication to Lav

1. Possible Causes

Aircraft Wiring
Circuit Breaker 32MG
Circuit Breaker 34MG
Circuit Breaker 39MG
Circuit Breaker 45MG
DEU-B 300RH
Flush Valve

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 23-73-47-000-001	Removal of the Decoder/Encoder Unit B (300RH)
AMM 23-73-47-400-001	Installation of the Decoder/Encoder Unit B (300RH)
AMM 38-31-00-710-009	Operational Test of the Toilet Unit
AMM 38-31-00-740-001	BITE Test of the Vacuum Toilet System
ASM 383111
AMM 38-31-57-000-001	Removal of the Flush Valve
AMM 38-31-57-400-001	Installation of the Flush Valve
MCDU Display

3. Fault Confirmation
Subtask 38-31-00-710-117-A ** ON A/C NOT FOR ALL

A. Do a test of the vacuum toilet system AMM 38-31-00-710-009.

Subtask 38-31-00-740-071-A ** ON A/C NOT FOR ALL

B. Do the procedure to get access to the CFDS SYSTEM REPORT/TEST menu PAGE AMM 38-31-00-740-001.

4. Fault Isolation
Subtask 38-31-00-810-134-C ** ON A/C NOT FOR ALL

A. If the LAST/PREVIOUS LEGS Report gives the maintenance message
TOILET ASSY LAV X
FCU / DEU-B (FIN)
and
the FAP gives the maintenance message CHECK LAVATORY - POWER SUPPLY LAV XX:

do a check of the Aircraft Wiring between the DEU-B and the related lavatory and repair if necessary ASM 383111.

(1) If the fault continues:

Open and close the related Circuit Breaker 32MG or Circuit Breaker 34MG or Circuit Breaker 39MG or Circuit Breaker 45MG .

(2) If the fault continues:

Replace the related DEU-B 300RH , AMM 23-73-47-000-001 and AMM 23-73-47-400-001.

(3) If the fault continues:

Replace the related Flush Valve , AMM 38-31-57-000-001 and AMM 38-31-57-400-001.

Subtask 38-31-00-710-120-A ** ON A/C NOT FOR ALL

B. Test
(1) Do the test as given in paragraph 3. A. to check the correct operation.
(2) After the subsequent flight, make sure that the fault does not continue.

[Rev.8 from Aug 2018] 2026.04.04 04:34:15 UTC