DOC AIRBUS | TSM A320FFailure of the Throttle Control Unit on Engine 2
1. Possible Causes
· CTL UNIT-THROTTLE, ENG 2 ( 8KS2 )
· wiring from the EEC (4000KS) to the engine 2 throttle control unit (8KS2)
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
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 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 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. ASM 73-25-12
Ref. AMM 76-11-19-000-041 Removal of the Throttle Control Unit
REFERENCE DESIGNATION
Ref. AMM 76-11-19-400-041 Installation of the Throttle Control Unit
Throttle Control Unit (Engine 2) SHEET 1
Figure 76(IAE)-00-00-991-00200-B / SHEET 1/1 - Throttle Control Unit (Engine 2) not printed, as per
printing preferences
3. Fault Confirmation
Subtask 76-00-00-860-060-A
A. Job Set-up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
(2) On the panel 50VU, release the ENG/FADEC GND PWR/2 pushbutton switch.
Subtask 76-00-00-710-064-A
B. Test
(1) On the panel 50VU, push the ENG FADEC GND PWR 2 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 2 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 and let it become stable for 5
minutes.
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 2 by the discontinued start, restart and shutdown procedure Ref.
AMM 71-00-00-710-018 .
(7) Read the LAST LEG REPORT of the FADEC (2A and 2B) 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 2A or FADEC 2B which found the fault.
(8) Fully decrease the brightness of the MCDU screen (display off).
4. Fault Isolation
(Ref. Fig. Throttle Control Unit (Engine 2) SHEET 1)
Subtask 76-00-00-810-057-A
A. If the test gives the maintenance message TLA SENS/HC/EEC2:
· Replace the CTL UNIT-THROTTLE, ENG 2 ( 8KS2 ) Ref. AMM 76-11-19-000-041 and Ref.
AMM 76-11-19-400-041 .
(1) If the fault continues:
· Read the fault code shown on the FLIGHT DATA and GROUND DATA of the FADEC (2A and 2B)
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 2A menu gives the fault code TRAL:
· Do a check and repair the wiring from the EEC (4000KS) to the engine 2 throttle control unit
(8KS2) :
. pins J1/S, h, U, i, T, j to pins C/B, A, D, C, E, F Ref. ASM 73-25-12.
(b) If the FADEC 2B menu gives the fault code TRAL:
· Do a check and repair the wiring from the EEC (4000KS) to the engine 2 throttle control unit
(8KS2) :
. pins J7/S, h, U, i, T, j to pins D/B, A, D, C, E, F Ref. ASM 73-25-12.
(c) If the FADEC 2A and 2B menus give the fault code TRAXCF:
· Do a check and repair the wiring from the EEC (4000KS) to the engine 2 throttle control unit
(8KS2) :
. pins J1/S, h, U, i, T, j to pins C/B, A, D, C, E, F
. pins J7/S, h, U, i, T, j to pins D/B, A, D, C, E, F Ref. ASM 73-25-12.
(2) If the fault continues:
· Replace the EEC ( 4000KS ) Ref. AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
(3) Check the resistance values (in ohms) between the EEC and the throttle control unit (8KS2).
NOTE: Make sure that the resistance values (in ohms) between the EEC and the throttle control unit
(8KS2) do not exceed the values given in the table below:
A/C Type Engine 1
Channel A
Engine 1
Channel B
Engine 2
Channel A
Engine 2 Channel B
A318 5.45 2.97 5.30 2.81
A319 5.25 2.74 4.95 2.63
A320 5.46 2.94 5.10 2.62
A321 5.97 3.42 5.76 3.24
Subtask 76-00-00-710-065-A
B. Do the test given in Para. 3.
5. Close-up
Subtask 76-00-00-860-061-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/2 pushbutton switch.
(3) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 .
(4) Make sure that the fan cowls 447AL and 448AR are closed Ref. AMM 71-13-00-410-010 . [Rev.6 from Feb 2017] 2026.04.04 04:37:28 UTC