MCDU Shows Waste Tank Level 1% although the Waste Tank is Empty (0%)

TASK 38-31-00-810-855-A
MCDU Shows Waste Tank Level 1% although the Waste Tank is Empty (0%)

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
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

3. Fault Confirmation
Subtask 38-31-00-710-156-A ** ON A/C NOT FOR ALL

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

Subtask 38-31-00-740-085-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 38-31-00-810-157-A ** ON A/C NOT FOR ALL

A. If the MCDU gives the maintenance message WASTE TANK LEVEL 1%:

select the WATER/WASTE page on the FAP to get the real waste tank level.

Subtask 38-31-00-710-157-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.

[Rev.8 from Aug 2018] 2026.04.04 04:34:16 UTC