Loss of the FWC2 Input Signal Detected by the ATSU

TASK 46-21-00-810-832-A
Loss of the FWC2 Input Signal Detected by the ATSU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 31-53-34-000-001	Removal of the Flight Warning Computer (FWC)
AMM 31-53-34-400-001	Installation of the Flight Warning Computer (FWC)
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 46-21-00-740-110-A

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

4. Fault Isolation
Subtask 46-21-00-810-080-A

A. If the test gives the maintenance message FWC2(1WW2)/ATSU1(1TX1):

(1) If the fault continues:

(a) If the fault continues:

remove the FWC 2 and the ATSU
do a check and repair the wiring of the FWC DATA BUS : between pins AB/12J,12K of the FWC 2 and pins AB/6C,6D of the ATSU ASM 462105
install the FWC 2 and the ATSU.

Subtask 46-21-00-740-111-A

B. Do the test given in Para. 3.

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