DOC AIRBUS | TSM A320FFailure of the Active Clearance Control (ACC) Actuator on Engine 1
1. Possible Causes
NOTE: This task is to troubleshoot the Clear Language Message (CLM) ACC ACT/HC/EEC1. The fault acronyms
listed in the fault confirmation section below will help you to focus on the correct cause of this CLM.
· harness
· ACTUATOR-ACC ( 4027KS )
· EEC ( 4000KS )
· PUMP-HP/LP FUEL ( 2001EM )
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 71-13-00-410-010 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 73-12-41-000-010 Removal of the Low Pressure (LP)/High Pressure (HP) Fuel Pump
Ref. AMM 73-12-41-400-010 Installation of the Low Pressure (LP)/High Pressure (HP) Fuel Pump
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)
REFERENCE DESIGNATION
Ref. ASM 73-25-18
Ref. AMM 75-24-52-000-010 Removal of the High Pressure Turbine/Low Pressure Turbine (HPT/
LPT) Valve Actuator
Ref. AMM 75-24-52-400-010 Installation of the High Pressure Turbine/Low Pressure Turbine (HPT/
LPT) Valve 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
ACC Actuator SHEET 1
Figure 75(IAE)-24-00-991-00100-B / SHEET 1/1 - ACC Actuator not printed, as per printing
preferences
3. Fault Confirmation
Subtask 75-24-00-860-050-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 the FADEC GND PWR 1 pushbutton
switch.
Subtask 75-24-00-710-089-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 the fault acronym HCCWAF, fault acronym HCCL or fault acronym HCCXCF
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 HCCWAF 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 gives fault acronym HCCL in FADEC 1A or FADEC 1B or there are two or more
occurrences in fault history, continue with fault isolation Para. 4.B.
(c) If the test gives fault acronym HCCXCF in FADEC 1A or FADEC 1B or there are two or more
occurrences in fault history, continue with fault isolation Para. 4.C.
(d) If the test does not give the fault acronym HCCWAF, fault acronym HCCL or fault acronym
HCCXCF, send the engine back to service.
(3) If the readout gives the fault acronym HCCTK in FADEC 1A and FADEC 1B, do the steps in Para.
4.D. for fault confirmation (engine high power run 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 the fault acronym HCCTK or there are two or more occurrences in fault history,
continue with fault isolation Para. 4.D.
(b) If the test does not give the fault acronym HCCTK, send the engine back to service.
Subtask 75-24-00-710-098-A
C. Do a Test for Fault Acronym HCCTK
(1) On the ENG section of the maintenance panel 50VU, select FADEC GND PWR 1 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 or 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. ACC Actuator SHEET 1)
Subtask 75-24-00-810-052-A
A. Fault Isolation for Fault Acronym HCCWAF
A torque motor Wrap Around Fault (WAF) was found in channel A or channel B. The circuit for the ACC
actuator (4027KS) 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 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 ACC actuator
(4027KS) 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 (4027KS-A) from the
ACC actuator (4027KS) 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 ACC actuator (4027KS) Ref.
ASM 73-25-18:
1 Make sure that contacts 5 and 14 are not shorted to ground.
2 Make sure that contacts 5 and 14 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 5 to contact 14 is between 17 and 32 ohms.
4 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(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 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.
ACC Actuator Torque Motor Circuit Channel A Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J3)
Contacts Contacts
5 p
14 n
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 HCCWAF, send the engine back to service.
2 If the test gives the fault acronym HCCWAF, remove and replace the ACTUATORACC
( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
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 .
(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 ACC actuator
(4027KS) 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 (4027KS-A) from the
ACC actuator (4027KS) 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 torque motor circuit in the ACC actuator (4027KS) Ref.
ASM 73-25-18:
1 Make sure that contacts 16 and 15 are not shorted to ground.
2 Make sure that contacts 16 and 15 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 16 to contact 15 is between 17 and 32 ohms.
4 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(d) If no problems were found, disconnect electrical connector (4000KS-J9) 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.
(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.
ACC Actuator Torque Motor Circuit Channel B Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J9)
Contacts Contacts
16 p
15 n
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 HCCWAF, send the engine back to service.
2 If the test gives the fault acronym HCCWAF, remove and replace the ACTUATORACC
( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
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 .
Subtask 75-24-00-710-090-A
B. Fault Isolation for Fault Acronym HCCL
The ACC actuator LVDT signal is out of range. This is caused by an open, shorted 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-J2) to the ACC actuator
(4027KS) 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 (4027KS-A) from the
ACC actuator (4027KS) 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 ACC actuator (4027KS) Ref. ASM
73-25-18:
1 Make sure that contacts 10, 3, 8, and 9 are not shorted to ground.
2 Make sure that contacts 10, 3, 8 and 9 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 10 to contact 3 is between 86 and 146 ohms.
4 Make sure the resistance from contact 8 to contact 9 is between 40 and 67 ohms.
5 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(d) If no problems were found, 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.
(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 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.
ACC Actuator LVDT Circuit Channel A Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J2)
Contacts Contacts
10 P
3 f
8 R
9 g
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 HCCL, send the engine back to service.
2 If the test gives the fault acronym HCCL, remove and replace the ACTUATORACC
( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
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 .
(2) If the fault was found in channel B, do the steps that follow:
(a) Visually examine the harness from EEC connector (4000KS-J8) to the ACC actuator (4027KS)
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 (4027KS-A) from the
ACC actuator (4027KS) 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 ACC actuator (4027KS) Ref. ASM
73-25-18:
1 Make sure that contacts 11, 12, 19 and 18 are not shorted to ground.
2 Make sure that contacts 11, 12, 19 and 18 are not shorted to other contacts in the
connector.
3 Make sure the resistance from contact 11 to contact 12 is between 86 and 146 ohms.
4 Make sure the resistance from contact 19 to contact 18 is between 40 and 67 ohms.
5 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(d) 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.
(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 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.
ACC Actuator LVDT Circuit Channel B Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J8)
Contacts Contacts
11 P
12 f
19 R
18 g
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 HCCL, send the engine back to service.
2 If the test gives the fault acronym HCCL, remove and replace the ACTUATORACC
( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
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 .
Subtask 75-24-00-810-081-A
C. Fault Isolation for Fault Acronym HCCXCF
The ACC actuator (4027KS) position signal does not agree with the signal from the opposite channel. This
is caused by an open, shorted 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 EEC connector (4000KS-J2) to the ACC actuator
(4027KS) 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 EEC connector (4000KS-J8) to the ACC actuator (4027KS)
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 (4027KS-A) from the
ACC actuator (4027KS) Ref. AMM 71-50-00-210-010 . Examine the male and female part 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 ACC actuator (4027KS) Ref. ASM
73-25-18:
1 Make sure that contacts 10, 3, 8 and 9 are not shorted to ground.
2 Make sure that contacts 10, 3, 8 and 9 are not shorted to other contacts in the connector.
3 Make sure the resistance from contact 10 to contact 3 is between 86 and 146 ohms.
4 Make sure the resistance from contact 8 to contact 9 is between 40 and 67 ohms.
5 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(e) Do this electrical check of the channel B LVDT circuit in the ACC actuator (4027KS) Ref. ASM
73-25-18:
1 Make sure that contacts 11, 12, 19 and 18 are not shorted to ground.
2 Make sure that contacts 11, 12, 19 and 18 are not shorted to other contacts in the
connector.
3 Make sure the resistance from contact 11 to contact 12 is between 86 and 146 ohms.
4 Make sure the resistance from contact 19 to contact 18 is between 40 and 67 ohms.
5 If a problem is found, remove and replace the ACTUATOR-ACC ( 4027KS ) Ref.
AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
(f) If no problems were found, 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.
(g) 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.
ACC Actuator LVDT Circuit Channel A Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J2)
Contacts Contacts
10 P
3 f
8 R
9 g
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(h) 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.
(i) 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.
ACC Actuator LVDT Circuit Channel B Harness
ACC Actuator (4027KS) EEC (4000KS)
(4027KS-A) (4000KS-J8)
Contacts Contacts
11 P
12 f
19 R
18 g
3 If a problem is found with the harness, repair or replace as necessary Ref. ASM 73-25-18.
(j) Install all removed connectors Ref. AMM 70-23-15-912-010 .
(k) Do the test for this fault, listed in Para. 3. for fault confirmation.
1 If the test does not give the fault acronym HCCXCF, send the engine back to service.
2 If the test gives the fault acronym HCCXCF, remove and replace the ACTUATORACC
( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref. AMM 75-24-52-400-010 .
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 .
Subtask 75-24-00-810-082-A
D. Fault Isolation for Fault Acronym HCCTK
A track-check fault was found in channel A or B. The ACC actuator (4027KS) 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 an electrical problem.
(1) Remove and replace the ACTUATOR-ACC ( 4027KS ) Ref. AMM 75-24-52-000-010 and Ref.
AMM 75-24-52-400-010 .
(2) Do the test for this fault, listed in Para. 3. for fault confirmation.
(3) If the test was satisfactory, send the engine back to service.
(4) If this fault continues, remove and replace PUMP-HP/LP FUEL ( 2001EM ) Ref.
AMM 73-12-41-000-010 and Ref. AMM 73-12-41-400-010 .
(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 the fault continues, do the steps that follow:
(a) Do the steps for fault acronym HCCWAF listed in Para. 4.A.
(b) Do the steps for fault acronym HCCXCF listed in Para. 4.C.
5. Close-up
Subtask 75-24-00-860-051-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 04:37:13 UTC