CAN Bus Problem FWD LDCC Smoke-Detection

TASK 26-16-00-810-815-A
CAN Bus Problem FWD LDCC Smoke-Detection

1. Possible Causes

wiring
FWD LDCC smoke detector

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 26-17-00-810-830-A	Unexpected Smoke Detector
AMM 26-10-00-740-802	Ground Scanning of the Cabin Intercommunication Data-System (CIDS) - Smoke Detection Function (SDF)
ASM 261602
AMM 26-16-15-000-001	Removal of the Cargo-Compartment Smoke Detectors
AMM 26-16-15-400-001	Installation of the Cargo-Compartment Smoke Detectors

3. Fault Confirmation
Subtask 26-16-00-865-061-A ** ON A/C NOT FOR ALL

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/CIDS/SDF/DIR2 ESS	18WH	C06
49VU	AIR COND/CIDS/SDF/DIR1 ESS	15WH	C05
122VU	AIR COND/CIDS/SDF/DIR NORM/2	14WH	T18
122VU	AIR COND/CIDS/SDF/DIR NORM/1	17WH	T17

Subtask 26-16-00-710-072-A ** ON A/C NOT FOR ALL

B. Test
(1) Open the circuit breakers 14WH, 15WH, 17WH and 18WH, wait for approximately 10 seconds and close them again, wait for a minimum of 30 seconds before you start the test.
(2) After a minimum time of 30 seconds, do the Ground Scanning of the Cabin Intercommunication Data-System (CIDS) - Smoke Detection Function (SDF) AMM 26-10-00-740-802.

4. Fault Isolation
Subtask 26-16-00-810-075-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 26-16-00-810-091-A ** ON A/C NOT FOR ALL

B. If the test gives the maintenance message WRG: CAN BUS X / SMK DET FWD LDCC (XWH), (XWH = FIN of the related smoke detector):
(1) If the test gives the additional message WRG: SMK DET ADDRESS/ CAN BUS X, start troubleshooting according to that message first (Ref. TSM TASK 26-17-00-810-830).
(2) If the fault continues:

Do a check and repair the wiring between the CIDS DIR 1 (101RH) and the FWD LDCC
do a check and repair the ASM 261602 between the CIDS DIR 1 (101RH) and the FWD LDCC

(3) If the fault continues:

Do a check and repair the wiring between the CIDS DIR 2 (102RH) and the FWD LDCC smoke detector XWH ASM 261602

(4) If the fault continues:

Replace the FWD LDCC smoke detector XWH AMM 26-16-15-000-001 and AMM 26-16-15-400-001.

Subtask 26-16-00-710-081-A ** ON A/C NOT FOR ALL

C. Do the test given in Para. 3.

5. Close-up
Subtask 26-16-00-860-064-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.

[Rev.8 from Aug 2018] 2026.04.04 04:27:19 UTC