Failure of the Pin-Programming (Mode Discrete or Parity) of the ISIS Indicator

TASK 34-22-00-810-816-A
Failure of the Pin-Programming (Mode Discrete or Parity) of the ISIS Indicator

1. Possible Causes

aircraft wiring
IND-ISIS [22FN]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 342203
AMM 34-22-25-000-001	Removal of the ISIS Indicator
AMM 34-22-25-400-001	Installation of the ISIS Indicator

3. Fault Confirmation
Subtask 34-22-00-700-062-A ** ON A/C NOT FOR ALL

A. Test
Not applicable, you cannot confirm this fault on the ground.

4. Fault Isolation
Subtask 34-22-00-810-072-A ** ON A/C NOT FOR ALL

A. If the fault symptom is identified by the maintenance message on the POST FLIGHT REPORT:
WRG: PIN PROG/<CR>ISIS (22FN-10FC)
and by the MAINT white flag on the face of the ISIS indicator:

remove the IND-ISIS (22FN) AMM 34-22-25-000-001
do a check of pins A/X, h, a on the rack connector
make sure that there is an open circuit between pins A/X, h, a.
do a check of pins A/b, c, d, e, k, m, p, s, r on the rack connector
compare the state of the pins A/b, c, d, e, k, m, p, s, r with the pin programming given in the ASM ASM 342203.

(1) If the pin programming is incorrect:

repair the aircraft wiring ASM 342203
install the IND-ISIS (22FN) AMM 34-22-25-400-001.

(2) If the pin programming is correct:

replace the IND-ISIS [22FN] AMM 34-22-25-000-001 AMM 34-22-25-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:32:57 UTC