DOC AIRBUS | TSM A320FFailure of the ACOC Modulating Valve on Engine 1
1. Possible Causes
NOTE: This task is to troubleshoot the Clear Language Message (CLM) ACOC AIR MOD VLV/HC/EEC1. The fault
acronyms listed in the fault confirmation section below will help you to focus on the correct cause of this
CLM.
· MODULATING VALVE-ACOC ( 4019KS )
· EEC ( 4000KS )
2 Job Set-up Information
A. Referenced Information
REFERENCE DESIGNATION
73-00-00-810-900-B Multiple Dual Track Check Faults on the Engine 1
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 71-00-00-710-013 Test No.11 : High Power Assurance Test
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 71-13-00-010-010 Opening of the Fan Cowls 437AL(447AL),438AR(448AR)
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 78-30-00-440-012 Re-activation of the Thrust Reverser Hydraulic Control Unit (HCU) after
Ground Maintenance
Ref. AMM 78-32-00-010-010 Opening of the Thrust Reverser Halves
Ref. AMM 78-32-00-410-010 Closing of the Thrust Reverser Halves
Ref. AMM 79-21-51-000-010 Removal of the Air Cooled Oil Cooler (ACOC) Modulating Valve
Ref. AMM 79-21-51-400-010 Installation of the Air Cooled Oil Cooler (ACOC) Modulating Valve
70-00-00-03-13 STANDARD PRACTICES - ENGINE - GENERAL - TASK SUPPORTING
DATA
ACOC Modulating Valve SHEET 1
Figure 79(IAE)-20-00-991-00100-A / SHEET 1/1 - ACOC Modulating Valve not printed, as per printing
preferences
3. Fault Confirmation
Subtask 79-20-00-860-050-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, release FADEC GND PWR 1 pushbutton
switch.
Subtask 79-20-00-710-084-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 and read the scheduled maintenance report to identify the fault
acronym related to the CLM (Ref. TSM 70-00-00-03) .
(2) If the readout gives fault acronym AIVWAF in FADEC 1A or FADEC 1B, do task operational test of
the FADEC system on the ground for fault confirmation Ref. AMM 73-22-00-710-040 .
(a) If the test gives the fault acronym AIVWAF in FADEC 1A or FADEC 1B, 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 acronym AIVWAF, and there is no history of this fault, send the
engine back to service.
(3) If the readout gives fault acronym AIVL, AIVXCF, AVOPTF or AVCLTF in FADEC 1A or FADEC 1B,
do the steps in Para. 3.C. for fault confirmation (Engine idle run for fault confirmation)
(a) If the test gives fault acronym AIVL, or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.B.
(b) If the test gives fault acronym AIVXCF, or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.C.
(c) If the test gives fault acronym AVOPTF, or there are two or more occurrences in fault history,
continue with fault fsolation Para. 4.D.
(d) If the test gives fault acronym AVCLTF, or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.D.
(e) If the test does not give fault acronym AIVL, AIVXCF, AVOPTF or AVCLTF and there is no
history of faults, send the engine back to service.
(4) If the readout gives fault acronym AIVTK in FADEC 1A or FADEC 1B, do the steps in Para. 3.D. for
fault confirmation (high power assurance test for fault confirmation)
NOTE: Multiple dual track check faults may indicate a failed fuel pump. Four control units on the
engine are driven by HP fuel: the VSV Actuator, the 2.5 bleed controller, the ACOC Air
Modulating Valve and the Active Clearance Control Actuator. If you have faults with two
or more of these units, you must follow the multiple dual track check faults procedure
(Ref. TSM 73-00-00-810-900) .
(a) If the test gives fault acronym AIVTK or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.D.
(b) If the test does not give fault acronym AIVTK, send the engine back to service.
Subtask 79-20-00-710-058-A
C. Do a Test for Fault Acronym AIVL, AIVXCF, AVOPTF or AVCLTF.
(1) On the ENG section of the maintenance panel 50VU, select FADEC GND PWR 1 pushbutton switch
to the ON position.
NOTE: This step resets the FADEC memory.
(2) Push the INIT mode key. The INIT page comes into view.
(3) 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: You must operate the engine for a minimum of three minutes. If not, the LAST LEG REPORT
will not be erased and the fault will not be kept again in the EEC LAST LEG REPORT.
(4) Do the shutdown of the engine 1 by the discontinued start, restart and shutdown procedure Ref.
AMM 71-00-00-710-018 .
(5) Read the LAST LEG REPORT and the scheduled maintenance report of the FADEC 1A and FADEC
1B menu on the MCDU (Ref. TSM 70-00-00-03) .
(a) Make a record of the fault message.
(b) Make a record of the channel FADEC 1A or FADEC 1B which found the fault.
(c) Do the CFDS message decoding and read the flight data and ground data to identify the fault
acronyme.
Subtask 79-20-00-710-091-A
D. Do a Test for Fault Acronym AIVTK
(1) On the ENG section of the maintenance panel 50VU, select FADEC GND PWR 1 pushbutton switch
to the ON position.
NOTE: This step resets the FADEC memory.
(2) Do the test No. 11: High power assurance test Ref. AMM 71-00-00-710-013 .
(3) Read the LAST LEG REPORT and the scheduled maintenance report of the FADEC 1A and FADEC
1B menu on the MCDU (Ref. TSM 70-00-00-03) .
(a) Make a record of the fault message.
(b) Make a record of the channel FADEC 1A or FADEC 1B which found the fault.
(c) Do the CFDS message decoding and read the flight data and ground data to identify the fault
acronym.
4. Fault Isolation
(Ref. Fig. ACOC Modulating Valve SHEET 1)
Subtask 79-20-00-810-054-A
A. Fault Isolation for Fault Acronym AIVWAF
A torque motor Wrap Around Fault (WAF) was detected in the channel A or B. The circuit for the ACOC
modulating valve is open, shorted to ground, or has a wire to wire short.
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) If the fault was found in channel A, do the steps that follow:
(a) Visually examine the harness from the EEC connector (4000KS-J3) to the ACOC modulatin valve
(4019KS) 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.
(b) If no problems were found with the harness, disconnect electrical connector (4100KS-A) from the
ACOC modulating valve (4019KS) 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.
(c) Do this electrical check of the channel A torque motor circuit in the ACOC modulating
valve(4019KS) Ref. ASM 73-25-18:
1 Make sure that contacts 3 and 2 are not shorted to ground.
2 Make sure that contacts 3 and 2 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 3 to contact 2 is between 86.4 and 100.7 ohms for
woodward type units and less than 100 ohms for Goodrich type units.
4 If a problem is found, remove and replace the MODULATING VALVE-ACOC ( 4019KS )
Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(d) If no problems were found, disconnect electrical connector (4000KS-J3) 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 or replace as necessary.
(e) Do this electrical check of the torque motor 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.
ACOC Modulation Valve Torque Motor Circuit Channel A Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-A) (4000KS-J3)
Contacts Contacts
3 c
2 d
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(f) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(g) Do the test for this fault, listed in Para. 3. for fault confirmation.
1 If the test does not give the fault acronym AIVWAF, send the engine back to service.
2 If the test gives the fault acronym AIVWAF, remove and replace MODULATING VALVEACOC
( 4019KS ) Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
3 If this fault continues, remove and replace EEC ( 4000KS ) Ref. AMM 73-22-34-000-010
and Ref. AMM 73-22-34-400-010 .
(2) If the fault was found in channel B, do the steps that follow:
(a) Visually examine the harness from the EEC connector (4000KS-J9) to the ACOC modulating
valve (4019KS) 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.
(b) If no problems were found with the harness, disconnect electrical connector (4019KS-B) from the
ACOC modulating valve (4019KS) 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 or replace as necessary.
(c) Do this electrical check of the channel B torque motor circuit in the ACOC modulating
valve(4019KS) Ref. ASM 73-25-18:
1 Make sure that contacts 3 and 2 are not shorted to ground.
2 Make sure that contacts 3 and 2 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 3 to contact 2 is between 86.4 and 100.7 ohms for
woodward type units and less than 100 ohms for Goodrich type units.
4 If a problem is found, remove and replace the MODULATING VALVE-ACOC ( 4019KS )
Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(d) If no problems were found, disconnect electrical connector (4000KS-J9) from the EEC (4000KS)
AMM TASK 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 or replace as necessary.
(e) Do this electrical check of the torque motor 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.
ACOC Modulation Valve Torque Motor Circuit Channel B Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-B) (4000KS-J9)
Contacts Contacts
3 c
2 d
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(f) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(g) Do the test for this fault, listed in Para. 3. for fault confirmation.
1 If the test does not give the fault acronym AIVWAF, send the engine back to service.
2 If the test gives the fault acronym AIVWAF, remove and replace MODULATING VALVEACOC
( 4019KS ) Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
3 If this fault continues, remove and replace EEC ( 4000KS ) Ref. AMM 73-22-34-000-010
and Ref. AMM 73-22-34-400-010 .
Subtask 79-20-00-810-069-A
B. Fault Isolation for Fault Acronym AIVL
The ACOC modulating valve LVDT signal is out of range. This is caused by an open, short to ground or a
wire to wire short in this circuit.
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) If the fault was found in channel A, do the steps that follow:
(a) Visually examine the harness from the EEC connector (4000KS-J4) to the ACOC modulating
valve (4019KS) 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.
(b) If no problems were found with the harness, disconnect electrical connector (4019KS-A) from the
ACOC modulating valve (4019KS) 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.
(c) Do this electrical check of the channel A LVDT circuit in the ACOC modulating valve (4019KS)
Ref. ASM 73-25-18:
1 Make sure that contacts 6, 7, 4, and 5 are not shorted to ground.
2 Make sure that contacts 6, 7, 4 and 5 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 6 to contact 7 is between 88.1 and 114.9 ohms for
woodward type units and between 240 and 385 ohms for goodrich type units.
4 Make sure the resistance from contact 4 to contact 5 is between 62.9 and 90.7 ohms for
woodward type units and between 560 and 825 ohms for goodrich type units.
5 If a problem is found, remove and replace the ACOC modulating valve (4019KS) Ref.
AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(d) If no problems were found, disconnect electrical connector (4000KS-J4) 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 or replace as necessary.
(e) 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 it 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.
ACOC Modulation Valve LVDT Circuit Channel A Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-A) (4000KS-J4)
Contacts Contacts
6 d
7 p
4 L
5 K
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(f) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(g) Do the test for this fault, listed in Para. 3. for fault confirmation.
1 If the test does not give the fault acronym AIVL send the engine back to service.
2 If the test gives the fault acronym AIVL, remove and replace MODULATING VALVEACOC
( 4019KS ) Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
3 If this fault continues, remove and replace EEC ( 4000KS ) Ref. AMM 73-22-34-000-010
and Ref. AMM 73-22-34-400-010 .
(2) If the fault was found in channel B, do the steps that follow:
(a) Visually examine the harness from the EEC connector (4000KS-J10) to the ACOC modulating
valve (4019KS) 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.
(b) If no problems were found with the harness, disconnect electrical connector (4019KS-B) from the
ACOC modulating valve (4019KS) 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.
(c) Do this electrical check of the channel B LVDT circuit in the ACOC modulating valve (4019KS)
Ref. ASM 73-25-18:
1 Make sure that contacts 6, 7, 4, and 5 are not shorted to ground.
2 Make sure that contacts 6, 7, 4 and 5 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 6 to contact 7 is between 88.1 and 114.9 ohms for
woodward type units and between 240 and 385 ohms for goodrich type units.
4 Make sure the resistance from contact 4 to contact 5 is between 62.9 and 90.7 ohms for
woodward type units and between 560 and 825 ohms for goodrich type units.
5 If a problem is found, remove and replace the ACOC modulating valve (4019KS) Ref.
AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(d) If no problems were found, disconnect electrical connector (4000KS-J10) 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 or replace as necessary.
(e) 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 it 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.
ACOC Modulation Valve LVDT Circuit Channel B Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-B) (4000KS-J10)
Contacts Contacts
6 d
7 p
4 L
5 K
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(f) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(g) Do the test for this fault, listed in Para. 3. for fault confirmation.
1 If the test does not give the fault acronym AIVL send the engine back to service.
2 If the test gives the fault acronym AIVL, remove and replace MODULATING VALVEACOC
( 4019KS ) Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
3 If this fault continues, remove and replace EEC ( 4000KS ) Ref. AMM 73-22-34-000-010
and Ref. AMM 73-22-34-400-010 .
Subtask 79-20-00-810-070-A
C. Fault Isolation for Fault Acronym AIVXCF
The ACOC modulating valve 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 cannel A EEC connector (4000KS-J4) to the ACOC
modulating valve (4019KS) 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.
(b) Visually examine the harness from the cannel B EEC connector (4000KS-J10) to the ACOC
modulating valve (4019KS) 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, disconnect electrical connector (4010KS-A) from the ACOC
modulating valve (4019KS) 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 ACOC modulating valve (4019KS)
Ref. ASM 73-25-18:
1 Make sure that contacts 6, 7, 4, and 5 are not shorted to ground.
2 Make sure that contacts 6, 7, 4 and 5 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 6 to contact 7 is between 88.1 and 114.9 ohms for
woodward type units and between 240 and 385 ohms for goodrich type units.
4 Make sure the resistance from contact 4 to contact 5 is between 62.9 and 90.7 ohms for
Woodward type units and between 560 and 825 ohms for Goodrich type units.
5 If a problem is found, remove and replace the MODULATING VALVE-ACOC ( 4019KS )
Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(e) If no problems were found, disconnect electrical connector (4019KS-B) from the ACOC
modulating valve (4019KS) 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 or replace as necessary.
(f) Do this electrical check of the channel B LVDT circuit in the ACOC modulating valve (4019KS)
Ref. ASM 73-25-18:
1 Make sure that contacts 6, 7, 4, and 5 are not shorted to ground.
2 Make sure that contacts 6, 7, 4 and 5 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 6 to contact 7 is between 88.1 and 114.9 ohms for
woodward type units and between 240 and 385 ohms for goodrich type units.
4 Make sure the resistance from contact 4 to contact 5 is between 62.9 and 90.7 ohms for
Woodward type units and between 560 and 825 ohms for Goodrich type units.
5 If a problem is found, remove and replace the MODULATING VALVE-ACOC ( 4019KS )
Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
(g) If no problems were found, disconnect electrical connector (4000KS-J4) 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 or replace 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.
ACOC Modulation Valve LVDT Circuit Channel A Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-A) (4000KS-J4)
Contacts Contacts
6 d
7 p
4 L
5 K
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-J10) 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 or replace 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.
ACOC Modulation Valve LVDT Circuit Channel B Harness
ACOC Modulating Valve (4019KS) EEC (4000KS)
(4019KS-B) (4000KS-J10)
Contacts Contacts
6 d
7 p
4 L
5 K
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 AIVXCF, send the engine back to service.
2 If the test gives the fault acronym AIVXCF, remove and replace MODULATING VALVEACOC
( 4019KS ) Ref. AMM 79-21-51-000-010 and Ref. AMM 79-21-51-400-010 .
3 If this fault continues, remove and replace EEC ( 4000KS ) Ref. AMM 73-22-34-000-010
and Ref. AMM 73-22-34-400-010 .
Subtask 79-20-00-810-071-A
D. Fault Isolation for Fault Acronym AIVTK, AVOPTF or AVCLTF
A track-check fault was found in the channel A or B. The ACOC modulating valve cannot move to its
commanded position or it moves slower than normal.
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: This fault is typically caused by a mechanical problem and not by an electrical problem.
(1) Open the thrust reverser halves Ref. AMM 78-32-00-010-010 and fan cowls as necessary Ref.
AMM 71-13-00-010-010 .
(2) Remove and replace MODULATING VALVE-ACOC ( 4019KS ) Ref. AMM 79-21-51-000-010 and
Ref. AMM 79-21-51-400-010 .
(3) Do the test for this fault, listed in Para. 3. for fault confirmation.
(4) If the test was satisfactory, send the engine back to service.
(5) 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 .
(6) If this fault continues, do the steps that follow:
(a) Do the steps for fault acronym AIVWAF listed in Para. 4.A.
(b) Do the steps for fault acronym AIVXCF listed in Para. 4.C.
5. Close-up
Subtask 79-20-00-860-051-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 04:38:26 UTC