Loss of the Data Loader Signal Detected by the ATSU

TASK 46-21-00-810-834-A
Loss of the Data Loader Signal Detected by the ATSU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-38-22-000-001	Removal of the MDDU
AMM 31-38-22-400-001	Installation of the MDDU
AMM 46-21-00-740-001	BITE Test of the ATIMS
ASM 462105
AMM 46-21-34-000-001	Removal of the Air Traffic Service Unit (ATSU)
AMM 46-21-34-400-001	Installation of the Air Traffic Service Unit (ATSU)

3. Fault Confirmation
Subtask 46-21-00-740-114-A

A. Test
(1) Do the BITE test of the ATIMS AMM 46-21-00-740-001.

4. Fault Isolation
Subtask 46-21-00-810-082-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DATA LOADER(1TD)/ATSU1(1TX1):

(1) If the fault continues:

remove the ATSU
do a check and repair the wiring of the DATA LOADER INPUT BUS : between pins 24,25 of the loading connector 183VC and the pins AA/8J,8K of the ATSU ASM 462105
install the ATSU.

Subtask 46-21-00-810-082-B ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DATA LOADER(1TD)/ATSU1(1TX1):

(1) If the fault continues:

(a) If the fault continues:

remove the MDDU and the ATSU
do a check and repair the wiring of the DATA LOADER INPUT BUS : between pins A/24,25 of the MDDU and pins AA/8J,8K of the ATSU ASM 462105
install the MDDU and the ATSU.

Subtask 46-21-00-810-082-E ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message DATA LOADER(1TD)/ATSU1(1TX1):

(1) If the fault continues:

Remove the ATSU.
Do a check and repair the wiring of the DATA LOADER INPUT BUS signal between ATSU (1TX1) pins AA/8J, 8K and connector 2TD pins 24,25 ASM 462105.
Install the ATSU.

Subtask 46-21-00-740-115-A

B. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:34:20 UTC