DOC AIRBUS | TSM A320FFailure of the Variable Stator Vane Actuator on Engine 1
1. Possible Causes
NOTE: This task is to troubleshoot the Clear Language Message (CLM) VSV ACT/HC/EEC1. The fault acronyms
listed in the fault confirmation section below will help you focus on the correct cause of the CLM.
· wiring from the ACTUATOR-VSV (4022KS) to the EEC (4000KS)
· ACTUATOR-VSV ( 4022KS )
· 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 70-23-15-912-010 Connection of Electrical Connectors
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 73-22-00-710-040 Operational Test of the FADEC SYSTEM on the Ground
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 73-25-18
Ref. AMM 75-32-41-000-010 Removal of the Variable Stator Vane (VSV) Actuator
Ref. AMM 75-32-41-400-010 Installation of the Variable Stator Vane (VSV) Actuator
Ref. AMM 78-30-00-440-012 Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after
Ground Maintenance
Ref. AMM 78-32-00-410-010 Closing of the Thrust Reverser Halves
70-00-00-03-13 STANDARD PRACTICES - ENGINE - GENERAL - TASK SUPPORTING
DATA
** ON A/C
POST SB 72-1036 for A/C 0101-0102, 0951-0951
Variable Stator Vane Actuator
Figure 75(IAE)-30-00-991-00200-A / SHEET 1/2 - Variable Stator Vane Actuator not printed, as per
printing preferences
Figure 75(IAE)-30-00-991-00200-A / SHEET 2/2 - Variable Stator Vane Actuator not printed, as per
printing preferences
3. Fault Confirmation
Subtask 75-30-00-860-056-A
A. Job Set-Up
(1) Energize the aircraft electrical circuits
Ref. AMM 24-41-00-861-002 .
(2) On the ENG section of the maintenance panel 50VU, select FADEC GND PWR 1 pushbutton switch
to the ON position.
Subtask 75-30-00-710-197-A
B. Identify the Test for Fault Confirmation
NOTE: Troubleshooting can start immediately without doing the fault confirmation if this CLM was shown
in multiple flight or ground legs.
(1) Do the CFDS message decoding to identify the fault acronym related to the CLM
(Ref. TSM 70-00-00-03) .
(2) If the readout gives the fault acronym SVAXCF in FADEC 1A or FADEC 1B, do the FADEC System
Operational Test for fault confirmation Ref. AMM 73-22-00-710-040 :
(a) If the test gives the fault acronym SVAXCF or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.A.
(b) If the test does not give the fault acronym SVAXCF and there is no history of faults, return the
engine to service.
4. Fault Isolation
** ON A/C
POST SB 72-1036 for A/C 0101-0102, 0951-0951
(Ref. Fig. Variable Stator Vane Actuator)
Figure 75(IAE)-30-00-991-00200-A / SHEET 1/2 - Variable Stator Vane Actuator not printed, as per printing
preferences
Figure 75(IAE)-30-00-991-00200-A / SHEET 2/2 - Variable Stator Vane Actuator not printed, as per printing
preferences
PRE SB 72-1036 for A/C 0101-0102, 0951-0951
Subtask 75-30-00-810-055-A
A. Fault Isolation for Fault Acronym SVAXCF
The VSV actuator position signal does not agree with the signal from the opposite channel. This
crosscheck fault (XCF) is caused by an open, short to ground or a wire to wire short in this circuit. This
fault will always be set in both channels.
NOTE: After each step that is done during this procedure, you can do the steps in Para. 3 to make sure
the fault is corrected.
NOTE: Disconnection and connection of the electrical connectors can correct this fault.
(1) Do the steps that follow:
(a) Visually examine the harness from the channel A EEC connector (4000KS-J2) to the VSV
actuator (4022KS) Ref. AMM 71-50-00-210-010 :
1 Look for harness damage.
2 Look for loose or damaged connectors.
3 Look for loose or damaged backshells.
NOTE: Loose backshells must be disassembled and examined for internal wiring chafing.
4 If a problem is found with the wiring from the ACTUATOR-VSV (4022KS) to the EEC
(4000KS) , repair or replace as necessary.
(b) Visually examine the harness from the channel B EEC connector (4000KS-J8) to the VSV
actuator (4022KS) Ref. AMM 71-50-00-210-010 :
1 Look for harness damage.
2 Look for loose or damaged connectors.
3 Look for loose or damaged backshells.
NOTE: Loose backshells must be disassembled and examined for internal wiring chafing.
4 If a problem is found with the harness, repair or replace as necessary.
(c) If no problems were found with the harness, disconnect electrical connector (4022KS-A) from the
VSV actuator (4022KS) Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the
connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(d) Do this electrical check of the channel A LVDT circuit in the VSV actuator (4022KS) Ref. ASM
73-25-18:
1 Make sure that contacts A, B, D and E are not shorted to ground.
2 Make sure that contacts A, B, D and E are not shorted to other contacts in the connector
3 Make sure the resistance from contact A to contact B is between 850 and 1100 ohms.
4 Make sure the resistance from contact D to contact E is between 250 and 340 ohms.
5 If a problem is found, remove and replace the ACTUATOR-VSV ( 4022KS ) Ref.
AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
(e) If no problems were found with the harness, disconnect electrical connector (4022KS-D) from the
VSV actuator (4022KS) Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the
connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(f) Do this electrical check of the channel B LVDT circuit in the VSV actuator (4022KS) Ref. ASM
73-25-18:
1 Make sure that contacts A, B, D and E are not shorted to ground.
2 Make sure that contacts A, B, D and E are not shorted to other contacts in the connector.
3 Make sure the resistance from contact A to contact B is between 850 and 1100 ohms.
4 Make sure the resistance from contact D to contact E is between 250 and 340 ohms.
5 If a problem is found, remove and replace the ACTUATOR-VSV ( 4022KS ) Ref.
AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
(g) If no problems were found with the VSV actuator (4022KS), disconnect electrical connector
(4000KS-J2) from the EEC (4000KS) Ref. AMM 71-50-00-210-010 Examine the male and
female parts of the connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket.You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(h) Do this electrical check of the LVDT wiring in the channel A harness. Look for:
1 Wire to wire shorts and shorts to ground:
· Wire to wire short check: Measure resistance between wires. If resistance is below
100000 (100K) ohms, then the wires are shorted and must be repaired.
· Wire to ground short check: Measure resistance between wire and engine metal or
ground. If resistance is below 100000 (100K) ohms, then the wire is shorted to ground and
must be repaired.
2 Continuity:
· Continuity check: Measure resistance between ends of same wire. If resistance is more
than 10 ohms, then the wire must be repaired.
NOTE: An incorrectly wired harness can cause this problem. When you test these circuits,
make sure the contacts are installed in the correct positions in each connector as
specified in the wiring diagram.
VSV Actuator LVDT Circuit Channel A Harness
VSV Actuator (4022KS) EEC (4000KS)
(4022KS-A) (4000KS-J2)
Contacts Contacts
A h
B s
D U
VSV Actuator LVDT Circuit Channel A Harness
VSV Actuator (4022KS) EEC (4000KS)
E T
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(i) If no problems were found, disconnect electrical connector (4000KS-J8) from the EEC (4000KS)
Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(j) Do this electrical check of the LVDT wiring in the channel B harness. Look for:
1 Wire to wire shorts and shorts to ground:
· Wire to wire short check: Measure resistance between wires. If resistance is below
100000 (100K) ohms, then the wires are shorted and must be repaired.
· Wire to ground short check: Measure resistance between wire and engine metal or
ground. If resistance is below 100000 (100K) ohms, then the wire is shorted to ground and
must be repaired.
2 Continuity:
· Continuity check: Measure resistance between ends of same wire. If resistance is more
than 10 ohms, then the wire must be repaired.
NOTE: An incorrectly wired harness can cause this problem. When you test these circuits,
make sure the contacts are installed in the correct positions in each connector as
specified in the wiring diagram.
VSV Actuator LVDT Circuit Channel B Harness
VSV Actuator (4022KS) EEC (4000KS)
(4022KS-D) (4000KS-J8)
Contacts Contacts
A h
B s
D U
E T
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(k) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(l) Do the test for this fault, listed in Para. 3 for fault confirmation.
1 If the test does not give the fault acronym SVAXCF , send the engine back to service.
2 If the test gives the fault acronym SVAXCF , remove and replace the ACTUATORVSV
( 4022KS ) Ref. AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
3 If this fault continues, remove and replace the EEC ( 4000KS ) Ref.
AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
** ON A/C
POST SB 72-1036 for A/C 0101-0102, 0951-0951
Subtask 75-30-00-810-055-B
A. Fault Isolation for Fault Acronym SVAXCF
The VSV actuator position signal does not agree with the signal from the opposite channel. This
crosscheck fault (XCF) is caused by an open, short to ground or a wire to wire short in this circuit. This
fault will always be set in both channels.
NOTE: After each step that is done during this procedure, you can do the steps in Para. 3 to make sure
the fault is corrected.
NOTE: Disconnection and connection of the electrical connectors can correct this fault.
(1) Do the steps that follow:
(a) Visually examine the harness from the channel A EEC connector (4000KS-J2) to the VSV
actuator (4022KS) Ref. AMM 71-50-00-210-010 :
1 Look for harness damage.
2 Look for loose or damaged connectors.
3 Look for loose or damaged backshells.
NOTE: Loose backshells must be disassembled and examined for internal wiring chafing.
4 If a problem is found with the wiring from the ACTUATOR-VSV (4022KS) to the EEC
(4000KS) , repair or replace as necessary.
(b) Visually examine the harness from the channel B EEC connector (4000KS-J8) to the VSV
actuator (4022KS) Ref. AMM 71-50-00-210-010 :
1 Look for harness damage.
2 Look for loose or damaged connectors.
3 Look for loose or damaged backshells.
NOTE: Loose backshells must be disassembled and examined for internal wiring chafing.
4 If a problem is found with the harness, repair or replace as necessary.
(c) If no problems were found with the harness, disconnect electrical connector (4022KS-A) from the
VSV actuator (4022KS) Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the
connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(d) Do this electrical check of the channel A LVDT circuit in the VSV actuator (4022KS) Ref. ASM
73-25-18.
1 Make sure that contacts A, B, D and E are not shorted to ground.
2 Make sure that contacts A, B, D and E are not shorted to other contacts in the connector.
3 Make sure the resistance from contact A to contact B is between 840 and 1260 ohms.
4 Make sure the resistance from contact D to contact E is between 328 and 482 ohms.
5 If a problem is found, remove and replace the ACTUATOR-VSV (4022KS) Ref.
AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
(e) If no problems were found with the harness, disconnect electrical connector (4022KS-D) from the
VSV actuator (4022KS) Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the
connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
(f) Do this electrical check of the channel B LVDT circuit in the VSV actuator (4022KS) Ref. ASM
73-25-18:
1 Make sure that contacts A, B, D and E are not shorted to ground.
2 Make sure that contacts A, B, D and E are not shorted to other contacts in the connector.
3 Make sure the resistance from contact A to contact B is between 840 and 1260 ohms.
4 Make sure the resistance from contact D to contact E is between 328 and 482 ohms.
5 If a problem is found, remove and replace the ACTUATOR-VSV (4022KS) Ref.
AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
(g) If no problems were found with the VSV actuator (4022KS), disconnect electrical connector
(4000KS-J2) from the EEC (4000KS) Ref. AMM 71-50-00-210-010 Examine the male and
female parts of the connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket.You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(h) Do this electrical check of the LVDT wiring in the channel A harness. Look for:
1 Wire to wire shorts and shorts to ground:
· Wire to wire short check: Measure resistance between wires. If resistance is below
100000 (100K) ohms, then the wires are shorted and must be repaired.
· Wire to ground short check: Measure resistance between wire and engine metal or
ground. If resistance is below 100000 (100K) ohms, then the wire is shorted to ground and
must be repaired.
2 Continuity:
· Continuity check: Measure resistance between ends of same wire. If resistance is more
than 10 ohms, then the wire must be repaired.
NOTE: An incorrectly wired harness can cause this problem. When you test these circuits,
make sure the contacts are installed in the correct positions in each connector as
specified in the wiring diagram.
VSV Actuator LVDT Circuit Channel A Harness
VSV Actuator (4022KS) EEC (4000KS)
(4022KS-A) (4000KS-J2)
Contacts Contacts
A h
B s
D U
E T
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(i) If no problems were found, disconnect electrical connector (4000KS-J8) from the EEC (4000KS)
Ref. AMM 71-50-00-210-010 . Examine the male and female parts of the connection:
1 Examine pins and sockets (contacts) for alignment and damage.
2 Look for contacts pushed rearward into the connector face.
3 Look for ovalized sockets in the connector.
NOTE: This can be done by inserting a harness connector pin into each socket. You must
feel friction when you insert and remove the pin.
4 Repair as necessary.
(j) Do this electrical check of the LVDT wiring in the channel B harness. Look for:
1 Wire to wire shorts and shorts to ground:
· Wire to wire short check: Measure resistance between wires. If resistance is below
100000 (100K) ohms, then the wires are shorted and must be repaired.
· Wire to ground short check: Measure resistance between wire and engine metal or
ground. If resistance is below 100000 (100K) ohms, then the wire is shorted to ground and
must be repaired.
2 Continuity:
· Continuity check: Measure resistance between ends of same wire. If resistance is more
than 10 ohms, then the wire must be repaired.
NOTE: An incorrectly wired harness can cause this problem. When you test these circuits,
make sure the contacts are installed in the correct positions in each connector as
specified in the wiring diagram.
VSV Actuator LVDT Circuit Channel B Harness
VSV Actuator (4022KS) EEC (4000KS)
(4022KS-D) (4000KS-J8)
Contacts Contacts
A h
B s
D U
E T
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(k) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(l) Do the test for this fault, listed in Para. 3 for fault confirmation.
1 If the test does not give the fault acronym SVAXCF , send the engine back to service.
2 If the test gives the fault acronym SVAXCF , remove and replace the ACTUATORVSV
( 4022KS ) Ref. AMM 75-32-41-000-010 and Ref. AMM 75-32-41-400-010 .
3 If this fault continues, remove and replace the EEC ( 4000KS ) Ref.
AMM 73-22-34-000-010 and Ref. AMM 73-22-34-400-010 .
5. Close-up
Subtask 75-30-00-860-057-A
A. Put the aircraft back to its initial configuration.
(1) Make sure that the thrust reverser halves are closed Ref. AMM 78-32-00-410-010 .
(2) Activate the thrust reverser HCU Ref. AMM 78-30-00-440-012 .
(3) Make sure that the fan cowls 437AL and 438AR are closed Ref. AMM 71-13-00-410-010 .
(4) On the ECAM control panel, set the UPPER DISPLAY and LOWER DISPLAY potentiometers to OFF.
Ref. AMM 31-60-00-860-002 .
(5) On the ENG section of the maintenance panel 50VU, push the FADEC GND PWR 1 pushbutton
switch.
(6) De-energize the aircraft electrical circuits
Ref. AMM 24-41-00-862-002 .
(7) Remove the warning notice(s). [Rev.6 from Feb 2017] 2026.04.04 04:37:15 UTC