DOC AIRBUS | TSM A320FLoss of the N2 Signal on Engine 1
1. Possible Causes
· PMA-EEC ( 4005EV )
· wiring from the EEC (4000KS) to the engine dedicated alternator stator (4005EV)
· EEC ( 4000KS )
· IDG
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
Ref. AMM 24-21-00-710-042 Operational Test of the IDG Disconnect and Reconnect (Reset) Function
- Engine Static
Ref. AMM 24-21-00-720-042 Operational Test of the IDG Disconnect and Reconnect (Reset) Function
- Engine in Operation
Ref. AMM 24-21-51-000-010 Removal of the Integrated Drive Generator -IDG 1(2)
Ref. AMM 24-21-51-400-010 Installation of the Integrated Drive Generator -IDG 1(2)
Ref. AMM 24-41-00-861-002 Energize the Aircraft Electrical Circuits from the External Power
Ref. AMM 24-41-00-862-002 De-energize the Aircraft Electrical Circuits Supplied from the External
Power
Ref. AMM 31-60-00-860-002 EIS Stop Procedure
Ref. AMM 70-23-15-912-010 Connection of Electrical Connectors
Ref. AMM 71-00-00-710-018 Discontinued Start, Restart and Shutdown Procedures
Ref. AMM 71-00-00-710-043 Normal Engine Automatic Start Procedure
Ref. AMM 71-00-00-710-047 Normal Engine Manual Start Procedure
Ref. AMM 71-13-00-410-010 Closing of the Fan Cowls 437AL(447AL),438AR(448AR)
Ref. AMM 71-50-00-210-010 Wire Harness Visual Inspection - All Power Plant Electrical Cables
Ref. AMM 73-22-34-000-010 Removal of the Electronic Engine Control (EEC)
Ref. AMM 73-22-34-400-010 Installation of the Electronic Engine Control (EEC)
Ref. AMM 73-22-38-000-010 Removal of the Engine Dedicated Alternator (EDA) Stator and/or Cooling
Shroud
Ref. AMM 73-22-38-400-010 Installation of the Engine Dedicated Alternator (EDA) Stator and/or
Cooling Shroud
Ref. ASM 73-25-14
3. Fault Confirmation
Subtask 77-00-00-860-096-A
A. Job Set-up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
Subtask 77-00-00-710-244-A
B. Test
(1) On the panel 50VU, push the ENG FADEC GND PWR 1 pushbutton switch and release it again.
NOTE: This action resets the FADEC memory.
(2) Adjust the brightness of the MCDU screen.
(3) Push the INIT mode key. The INIT page comes into view.
(4) Enter a new flight number.
(5) Start the engine 1 by the normal engine automatic start procedure Ref. AMM 71-00-00-710-043 or
the normal engine manual start procedure Ref. AMM 71-00-00-710-047 .
NOTE: Operation of the engine for at least 3 minutes erases the LAST LEG REPORT related to the
last flight and the new fault is recorded in the EEC LAST LEG REPORT.
(6) Do a shutdown of the engine 1 by the discontinued start, restart and shutdown procedure Ref.
AMM 71-00-00-710-018 .
(7) Read the LAST LEG REPORT of the FADEC (1A and 1B) menu on the MCDU (Ref. 70-00-00 Page
Block 301 Task Supporting Data).
(a) Make a record of the maintenance message.
(b) Make a record of the channel FADEC 1A or FADEC 1B which found the fault.
(8) Fully decrease the brightness of the MCDU screen (display off).
4. Fault Isolation
Subtask 77-00-00-810-180-A
A. If the test gives the maintenance message ENG DED ALTERN/HC/EEC1:
· Examine the harness Ref. AMM 71-50-00-210-010 from the EEC (4000KS) to the engine dedicated
alternator stator (4005EV) Ref. ASM 73-25-14.
(1) If the fault continues:
· Disconnect the connectors from the engine dedicated alternator stator (4005EV)
· Examine the connectors and receptacles Ref. AMM 71-50-00-210-010
· Connect the connectors to the engine dedicated alternator stator (4005EV) Ref.
AMM 70-23-15-912-010 .
(2) If the fault continues:
· Replace the PMA-EEC ( 4005EV ) Ref. AMM 73-22-38-000-010 and Ref.
AMM 73-22-38-400-010 .
(3) If the fault continues:
· Read the fault code shown on the FLIGHT DATA and GROUND DATA of the FADEC (1A and 1B)
menu on the MCDU (Ref. 70-00-00 Page Block 301 Task Supporting Data).
· Make a record of the fault code.
(a) If the FADEC 1A menu gives the fault code N2L:
· Do a check and repair the wiring from the EEC (4000KS) to the engine dedicated alternator
stator (4005EV) : pins J2/M, e to pins A/D, C.
(b) If the FADEC 1B menu gives the fault code N2L:
· Do a check and repair the:
. wiring from the EEC (4000KS) to the engine dedicated alternator stator
(4005EV) : pin J11/W to pin B/A
. wiring at the EEC connector (4000KS-J11) between pin V and pin U.
(c) If the FADEC 1A and 1B menus give the fault code N2XCF:
· Do a check and repair the :
. wiring from the EEC (4000KS) to the engine dedicated alternator stator
(4005EV)
* pins J2/M, e to pins A/D, C
* pin J11/W to pin B/A
. wiring at the EEC connector (4000KS-J11) between pin V and pin U.
(d) If the FADEC 1A menu gives the fault code ALTCRF:
· Do a check and repair the wiring from the EEC (4000KS) to the engine dedicated alternator
stator (4005EV)
. pins J5/W, j, A, X, B, Y to pins A/A, B, E, J, F, G
. pins J2/M, e to pins A/D, C.
(e) If the FADEC 1B menu gives the fault code ALTCRF:
· Do a check and repair the:
. wiring from the EEC (4000KS) to the engine dedicated alternator stator
(4005EV) : pins J11/W, j, A, X, B, Y to pins B/A, B, E, J, F, G
. wiring at the EEC connector (4000KS-J11) between pin V and pin U.
(4) If the fault continues:
· Replace the EEC ( 4000KS ) Ref. AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
(5) If the fault continues:
· Disconnect the Integrated Drive Generator (IDG) Ref. AMM 24-21-00-710-042 or Ref.
AMM 24-21-00-720-042 .
· If this action fixes the issue, replace the IDG Ref. AMM 24-21-51-000-010 and Ref.
AMM 24-21-51-400-010 .
(6) If the fault continues:
· Reconnect the IDG Ref. AMM 24-21-00-710-042 or Ref. AMM 24-21-00-720-042 .
Subtask 77-00-00-710-245-A
B. Do the test given in Para. 3.
5. Close-up
Subtask 77-00-00-860-097-A
A. Put the aircraft back to its initial configuration.
(1) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
Ref. AMM 31-60-00-860-002
(2) On the panel 50VU, push the ENG FADEC GND PWR/1 pushbutton switch.
(3) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 .
(4) Make sure that the fan cowls 437AL and 438AR are closed Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:37:50 UTC