W DOC AIRBUS | TSM A320F

CAN Bus A or CAN Bus B Failure

TASK 26-16-00-810-816-A
CAN Bus A or CAN Bus B Failure

1. Possible Causes
  • wiring
  • DIR-CIDS, 1 [101RH]
  • connectors
  • DIR-CIDS, 2 [102RH]
  • shield of the wiring
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 23-73-34-000-001
Removal of the CIDS Director
AMM 23-73-34-400-001
Installation of the CIDS Director
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 26-16-00-865-062-A ** ON A/C NOT FOR ALL
A. Table of the circuit breakers used in this procedure:
PANELDESIGNATIONFINLOCATION
** ON A/C NOT FOR ALL
49VUCOM/CIDS/DIR ESS/2157RHG02
** ON A/C NOT FOR ALL
49VUAIR COND/CIDS/SDF/DIR2 ESS18WHC06
49VUAIR COND/CIDS/SDF/DIR1 ESS15WHC05
49VUCOM/CIDS/DIR ESS/1150RHG01
** ON A/C NOT FOR ALL
49VUCOM DIR ESS/2157RHG02
** ON A/C NOT FOR ALL
121VUCOM NAV/CIDS/DIR NORM/2156RHM06
121VUCOM NAV/CIDS/DIR NORM/1151RHM05
121VUCOM NAV/CIDS/DIR NORM/1151RHM05
** ON A/C NOT FOR ALL
121VUCOM/CIDS/DIR 2/BAT146RHP14
121VUCOM/CIDS/DIR 1/BAT147RHP13
** ON A/C NOT FOR ALL
121VUCOM NAV/CIDS/DIR NORM/2156RHM07
121VUCOM NAV/CIDS/DIR NORM/1151RHM06
121VUCOM NAV/CIDS/DIR NORM/1151RHM06
** ON A/C NOT FOR ALL
122VUAIR COND/CIDS/SDF/DIR NORM/214WHT18
122VUAIR COND/CIDS/SDF/DIR NORM/117WHT17
Subtask 26-16-00-710-073-A ** ON A/C NOT FOR ALL
B. Test
   (1) Deactivation of the CIDS Directors
     (a) On circuit breaker panel 49VU, open circuit breakers 15WH and 18WH, then open circuit breakers 150RH and 157RH.
     (b) On circuit breaker panel 121VU, open circuit breakers 17WH and 14WH, then open circuit breakers 151RH and 156RH.
   (2) Reactivation of the CIDS Directors
     (a) After a minimum of 5 seconds from power-down, on circuit breaker panel 121VU, close circuit breakers 151RH and 156RH.
     (b) On circuit breaker panel 49VU, close circuit breakers 150RH and 157RH.
NOTE: The CIDS-SDF1 and CIDS-SDF2 must be energized in maximum 30 seconds after the CIDS is energized.
     (c) On circuit breaker panel 49VU, close circuit breakers 15WH and 18WH at the same time.
     (d) On circuit breaker panel 121VU, in maximum 2 seconds after the CIDS-SDF1 and CIDS-SDF2 essential busses are energized, close circuit breakers 17WH and 14WH at the same time.
   (3) 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 26-16-00-810-076-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 26-16-00-810-093-A ** ON A/C NOT FOR ALL
B. If the test gives the maintenance message WRG: CAN BUS X:
  • Do a check of the CAN BUS wiring between DIR-CIDS, 1 [101RH] and the last smoke detector on the related CAN BUS for continuity ASM 261602.
   (1) If the measured resistance value is higher than 20 Ohms:
  • Do a check and repair all the connectors and the wiring between DIR-CIDS, 1 [101RH] and the smoke detectors ASM 261602.
   (2) If the fault continues:
  • Do a check of the CAN bus wiring between DIR-CIDS, 2 [102RH] and the last smoke detector on the related CAN BUS for continuity ASM 261602.
     (a) If the measured resistance value is higher than 20 Ohms:
  • Do a check and repair all the connectors and the wiring between DIR-CIDS, 2 [102RH] and the smoke detectors ASM 261602.
   (3) If the fault continues:
     (a) Replace DIR-CIDS, 1 [101RH] AMM 23-73-34-000-001 and AMM 23-73-34-400-001.
   (4) If the fault continues:
     (a) Replace DIR-CIDS, 2 [102RH] AMM 23-73-34-000-001 and AMM 23-73-34-400-001.
   (5) If the fault continues:
  • Measure the resistance between CAN H and CAN L at the first smoke detector on the related CAN bus. All the equipment (the CIDS directors and the smoke detectors) other than the first smoke detector must be connected to the CAN bus.
     (a) If the measured resistance value is equal to 120 Ohms:
       1 Do a check and repair the wiring of the last smoke detector on the bus between pins R and P (bridgewire) ASM 261602.
       2 If the fault continues:
     (b) If the measured resistance value is less than 50 Ohms:
       1 Replace all the smoke detectors on the related CAN bus one by one AMM 26-16-15-000-001 and AMM 26-16-15-400-001.
After each smoke detector replacement, examine if the measured resistance value has changed.
       2 If the fault continues:
  • Do a check and repair the wiring between CAN H and CAN L for short circuits ASM 261602.
     (c) If the measured resistance value is approximately 60 Ohms:
       1 Do a check and repair the wiring between CAN H and GND for short circuits ASM 261602.
       2 If the fault continues:
  • Do a check and repair the wiring between CAN L and GND for short circuits ASM 261602.
   (6) If the fault continues:
     (a) Do a check and if necessary repair the shield of the wiring between DIR-CIDS, 1 [101RH] (or DIR-CIDS, 2 [102RH] ) and the LDCC smoke detectors ASM 261602.
Subtask 26-16-00-710-082-A ** ON A/C NOT FOR ALL
C. Do the test given in Para. 3.
5. Close-up
Subtask 26-16-00-860-065-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
   (1) Make sure that the work area is clean and clear of tools and other items.
[Rev.8 from Aug 2018] 2026.04.04 04:27:19 UTC
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