Circuit breaker / CAN BUS fault

TASK 23-73-00-810-950-A
Circuit breaker / CAN BUS fault

1. Possible Causes

2. Fault Confirmation
Subtask 23-73-00-710-383-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the SYSTEM TEST of the CIDS-SDF system.
(a) On the MCDU:

Set the "SYSTEM REPORT / TEST" page
Set the "FIRE PROT" page
Set the"SMOKE" (or "SDCU" and on the subsequent page "NEXT PAGE" as specified by the installed CFDIU-standard) page
Set the "SYSTEM TEST" page in the CIDS-SDF menu.

3. Fault Isolation
Subtask 23-73-00-810-731-A ** ON A/C NOT FOR ALL

A. If the test gives a different maintenance message, do the trouble shooting procedure related to the maintenance message.

Subtask 23-73-00-810-732-A ** ON A/C NOT FOR ALL

B. If the test gives a CIRCUIT BREAKER 14WH / CAN BUS B or CIRCUIT BREAKER 15WH / CAN BUS A message:
(1) Make sure that the circuit breaker is closed.
(2) Do a check and repair the wiring between the related circuit breaker and the related CIDS-SDF channel.
(3) If the fault continues:
(a) Do a check and repair the wiring between the related SDF channel and the first smoke detector:

1WH if the message is CIRCUIT BREAKER 15WH / CAN BUS A
2WH if the message is CIRCUIT BREAKER 14WH / CAN BUS B.

Subtask 23-73-00-710-384-A ** ON A/C NOT FOR ALL

C. Test
Do the test given in Para. 3.

4. Close-up
Subtask 23-73-00-860-057-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:26:00 UTC