TM 55-1520-240-T 4-12.4    FULL AUTHORITY DIGITAL ELECTRONIC CONTROL (FADEC) OPERATIONAL CHECK 4-12.4 INITIAL SETUP References: Applicable Configurations: TM 55-1520-240-23 With 74 Equipment Condition: Tools: TM 55-1520-240-23: Electrical Repairer's Tool Kit, Battery Connected NSN 5180-00-323-4915 Electrical Power On Materials: Hydraulic Power On None Visual Check of FADEC Performed (Task 4-12.3) Personnel Required: Aircraft Electrician TASK RESULT 1. Check that ENGINE NO. 1 PRI CONT, REV CONT and If circuit breaker (1, 2 or 3) is open, close it.  If circuit START & IGN circuit breakers (1, 2  and 3) are closed. breaker (1, 2 or 3) opens again, go to task 4-12.5, task 4-12.6 or task 4-10.5, respectively. 2. Check that ENGINE NO. 2 PRI CONT, REV CONT and If circuit breaker (4, 5 or 6) is open, close it.  If circuit START & IGN circuit breakers (4, 5  and 6) are closed. breaker (4, 5 or 6) opens again, go to task 4-12.5, task 4-12.6 or task 4-10.6, respectively. 3. On FADEC control panel (7),  set 1 and 2 PRI/ REV Cautions (10 and 11) should be out.  If either caution is switches (8 and 9) to PRI.  Check FADEC 1 and FADEC   illuminated, go to task 4-12.7. 2 cautions (10 and 11). 4. Look at fault display (12) on DECU No. 1 and No. 2 (13 Display should show 88.  If any other code shown, copy and 14). code and refer to Table 1 for maintenance action. 5. On ENGINE CONDITION quadrant (15), move NO. 1 Each display should show 88.  If any other code shown, and NO. 2 levers (16  and 17) to GROUND.  Look at copy code and refer to Table 1 for maintenance action. fault display (12) on DECU No. 1 and No. 2 (13 and 14). 6. Open ENGINE NO. 1 and NO. 2 PRI CONT circuit Cautions (10 and 11) should be illuminated.  Fault display breakers (1 and 4).  Check FADEC 1 and 2 cautions (10 (12) on both DECUs (13 and 14) should be blank. and 11) and fault display (12). 7. Open ENGINE NO. 1 REV CONT circuit breaker (2).   Caution (10) should go out.  DECU No. 1 display should Close ENGINE NO. 1 PRI CONT circuit breaker (1).   show code A6.  If it does not, replace DECU No. 1. Move 1 PRI/ REV switch (8)  to REV and back to PRI. Check FADEC 1 caution (10) and fault display (12). 8. Close ENGINE NO. 1 REV CONT circuit breaker (2).   Caution (10) shall illuminate. Open ENGINE NO. 1 PRI CONT circuit breaker (1). 9. Open ENGINE NO. 2 REV CONT circuit breaker (5).   Caution (11) should go out.  DECU No. 2 display should Close ENGINE NO. 2 PRI CONT circuit breaker (4).   show code A6.  If it does not, replace DECU No. 2. Move 2 PRI/ REV switch (11)  to REV and back to PRI. Check FADEC 2 caution (11) and fault display (12) on DECU (14). TASK RESULT 10. Close ENGINE NO. 2 REV CONT circuit breaker (5). Caution (11) shall illuminate. Close ENGINE NO. 1 PRI CONT circuit breaker (1). 11. Move pilot's thrust control (18) through its range. Fault display (12) on both DECUs (13 and 14) should Check fault display (12) on DECU No. 1 and No. 2 (13 show 88.  If not, copy code and refer to Table 1 for and 14). maintenance action. 12. On ENGINE CONDITION quadrant (15), move NO. 1 and NO. 2 levers (16 and 17) to STOP. FOLLOW-ON MAINTENANCE: TM 55-1520-240-23: Hydraulic power off. Electrical power off. Battery disconnected. Table 1.  DECU FAULT DISPLAY CODE MAINTENANCE ACTION FAULT MAINTENANCE ACTION/ FAULT MAINTENANCE ACTION/ CODE REFER TO TASK CODE REFER TO TASK 10 to 18 Replace DECU. D0 Replace DECU. 1B and 1C Replace DECU. D1 Refer to task 4-12.33. 1E and 1F Replace DECU D2 Refer to task 4-12.34. A1 Refer to task 4-12.8. D3 to D9 Replace DECU. A2 Refer to task 4-12.9. DA to DD Replace DECU. A3 Refer to task 4-12.10. DE Refer to task 4-12.35. A4 Refer to task 4-12.11. DF Replace DECU. A5 Refer to task 4-12.12. E1 Refer to task 4-12.19. A6 Refer to task 4-12.13. E2 Refer to task 4-12.20. A7 Refer to task 4-12.14. E3 Refer to task 4-12.21. B2 Refer to task 4-12.24. E4 Refer to task 4-12.22. B3 Refer to task 4-12.22. E5 Replace N2 Sensor. B4 Refer to task 4-12.19. Fl Refer to task 4-12.23. B5 Refer to task 4-12.10. F2 Refer to task 4-12.24. B6 Refer to task 4-5.4. F3 Replace HMU. B7 Refer to task 4-12.27. F4 Refer to task 4-12.25. B9 Replace DECU. F5 Refer to task 4-12.26. BA to BC Replace DECU. F6 Refer to task 4-12.27. C1 to C8 F7 Refer to task 4-12.28. and CF Refer to task 4-12.15 or 4-12.16. F8 Refer to task 4-12.29. C1 to C8 Replace other DECU. F9 Refer to task 4-12.30. C9 Refer to task 4-12.17 or 4-12.18. FA Refer to task 4-12.31. CF Replace other DECU. FB Refer to task 4-12.32. GO TO NEXT PAGE 4-268  Change 17  Page 4-267 is a blank page.