Fault Message:

RAT GCU INTERFACE FAILED

Fault Code:

2460493DCP

Associated CAS:

ELEC SYS FAIL
(Caution)

Battery/Ram-Air-Turbine Interface (BAT RAT I/F) Card in DC Power Center (DCPC) did not receive one or more of the following signals during the RAT TEST; RAT Line Contactor (RATLC) Status from Cockpit Circuit Breaker Panel (CCBP), RAT DEPLOYED status from Ram-Air-Turbine Generator Control Unit (RAT GCU), and RAT GCU test from RAT GCU.

• Cockpit Circuit Breaker Panel (CCBP) (A35)
• Ram-Air-Turbine (RAT) Line Contactor (RATLC) (K3)
• Ram-Air-Turbine Generator Control Unit (RAT GCU) (A191)
• Battery/Ram-Air-Turbine Interface (BAT RAT I/F) Card
• DC Power Center (DCPC) (A63)
• Ram-Air-Turbine (RAT) Manual Release Cable (S28)
• Associated Wiring

Advisory Wire/Service Bulletin: None

Forum Articles/Infoservice/Newsletter: None

1. Make sure the RAT is not deployed. Remove power from the A/C. Disconnect DCPC connector A63P2. Perform a continuity check as follows:

   From	To	Result
   A63P2-J	Ground

   1. If there is no continuity, go to step 4.
   2. If there is continuity, continue with next step.

2. Access the CCBP K3. Disconnect RATLC (K3) contact 12. Perform a continuity check as follows:
   

   RATLC (K3)

   From	To	Result
   A63P2-J	Ground

   1. If there is continuity, repair defective wiring as required and do close out.
   2. If there is no continuity, continue with the next step.

3. Replace RATLC K3.

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

4. Disconnect RAT GCU connector A191P1. Perform a continuity check as follows:

   From	To	Result
   A191P1-P	191P1-a

   1. If there is continuity, go to step 6
   2. If there is no continuity, continue with the next step.

5. Disconnect S28PI. Perform a continuity check as follows:
   

   RAT Manual Release (S28)

   From	To	Result
   S28P1-K	S28P1-H

   1. If there is no continuity, replace the RAT manual release cable (S28) and do close out.
   2. If there is continuity, continue with the next step.

6. Remove DCPC BATT/RAT interface card.
7.  Perform a continuity check as follows:

   From	To	Result
   A191P1-A	Ground
   A191P1-B	Ground
   A191P1-V	Ground

   1. If there is continuity, disconnect DCPC connector A63P2 and continue with the next step.
   2. If there is no continuity, continue with step 9.

8. Perform a continuity check as follows:

   From	To	Result
   A191P1-A	Ground
   A191P1-B	Ground
   A191P1-V	Ground

   1. If there is no continuity, go to step 15.
   2. If there is continuity, repair defective wiring as required and do the close out.

9. Perform a continuity check as follows:

   From	To	Result
   A191P1-A	A63P2-M
   A191P1-B	A63P2-L
   A191P1-V	A63P2-H

   1. If there is no continuity, repair defective wiring as required and do close out.
   2. If there is continuity, continue with the next step.

10. Perform a continuity check on the DCPC as follows:

    From	To	Result
    A63J2-L	Ground

    1. If there is no continuity. go to step15.
    2. If there is continuity, continue with the next step.

11. Perform a continuity check as follows:

    From	To	Result
    A63J2-M	P410A-8
    A63J2-J	P410A-11
    A63J2-H	P410A-12

    1. If there is no continuity. go to step15.
    2. If there is continuity, continue with the next step.

12. Disconnect RATLC K3 contact 12. Perform a continuity check as follows:

    From	To	Result
    K3-12	A63P2-J

    1. If there is no continuity, repair defective wiring as required and do the close out.
    2. If there is continuity, continue with the next step.

13. Replace BATT/RAT interface card. Is the fault resolved?

    1. If Yes, do the close out.
    2. If No, continue with the next step.

14. Replace RAT GCU.

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

15. Replace DCPC.
16. Do the close out.