Fault Message:

[ACSC2-A] CKPT DUCT OVERHEAT

Fault Code:

2163518ECS

Associated CAS:

TRIM AIR FAIL
(Caution)

The Cockpit Cabin Duct has been detected in overheat condition by the Right Air Conditioning Controller (ACSC) 2.

1. Access CAIMS and check cockpit DTS temperature reading. (CAIMS path: SYSTEM DIAG/AIR CONDITIONING/ACSC1A/LRU TEST/ACSC 2A/R ACSC CH. A TRIM & CABIN TEMP SENSOR DATA). It should change with cabin temp commands.

   1. If temperature reading does not change, go to step 10.
   2. If temperature reading changes, continue with next step.

2. Select the Aux Press Switch (SDS7) from the Bleed Air Control Panel to ON and then to OFF. Make sure the forward TAV go full open and full close according to the switch position (refer to Air Conditioning synoptic page).
3. Swap cockpit TAV with FWD TAV or AFT TAV.

   1. If the system checks are good, replace cockpit TAV and perform step 1 again.
   2. If the fault remains, continue with next step.

4. Perform wiring checks between Bleed Air Control Panel Aux Press Switch (SDS7) and JB5.

   1. If wiring checks are not good, repair defective associated wiring and do close out.
   2. If wiring checks are good, continue with next step.

5. Perform continuity check of JB5.

   1. If there is no continuity, replace JB5 and do close out.
   2. If there is continuity, continue with next step.

6. Perform wiring checks between JB5 and forward TAV including the ground.

   1. If wiring checks are not good, repair defective associated wiring and do close out.
   2. If wiring checks are good, continue with next step.

7. Make sure power from SPDA 2 is received at JB5.
8. Perform wiring checks between SPDA 2 and JB5 as follow:
   

   From	To	Result
   A14P4-C	JB5

   1. If wiring checks are not good, repair defective associated wiring and do close out.
   2. If wiring checks are good, continue with next step.

9. Perform continuity check of JB5.

   1. If there is no continuity, replace JB5 and do close out.
   2. If there is continuity, continue with next step.

10. Perform wiring checks between ACSC 2 and duct temp sensor 3 (E28).

    1. If wiring checks are not good, repair defective associated wiring and do close out.
    2. If wiring checks are good, continue with next step.

11. Perform wiring checks between ACSC 2 and forward Vent Sensor (B20).

    1. If wiring checks are not good, repair defective associated wiring and do close out.
    2. If wiring checks are good, continue with next step.

12. Swap cockpit DTS with FWD DTS or AFT DTS.

    1. If the system checks are good, replace cockpit DTS and do close out.
    2. If the fault remains, continue with next step.

13. Swap cockpit vent sensor with FWD vent sensor or AFT vent sensor.

    1. If the system checks are good, replace cockpit vent sensor and do close out.
    2. If the fault remains, continue with next step.

14. Perform continuity check of JB5.

    1. If there is no continuity, replace JB5 and do close out.
    2. If there is continuity, continue with next step.

15. Replace ACSC 2.
16. Do close out.