W DOC AIRBUS | TSM A320F

Loss of the FMV Torque Motor Control through the Two Channels on Engine 1

TASK 73-29-00-810-856-A
Loss of the FMV Torque Motor Control through the Two Channels on Engine 1

1. Possible Causes
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-10-000-001
Removal of the Hydromechanical Unit (HMU)
AMM 73-21-10-000-002
Removal of the Hydromechanical Unit (HMU)
AMM 73-21-10-400-001
Installation of the Hydromechanical Unit (HMU)
AMM 73-21-10-400-002
Installation of the Hydromechanical Unit (HMU)
AMM 73-21-50-000-006
Removal of J7 Harness
AMM 73-21-50-000-007
Removal of J8 Harness
AMM 73-21-50-000-040
Removal of the HJ7 Harness for SAC Engines
AMM 73-21-50-000-041
Removal of the HJ8 Harness for SAC Engines
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-006
Installation of the J7 Harness
AMM 73-21-50-400-007
Installation of the J8 Harness
AMM 73-21-50-400-040
Installation of the HJ7 Harness for SAC Engines
AMM 73-21-50-400-041
Installation of the HJ8 Harness for SAC Engines
AMM 73-21-60-000-001
Removal of the Electronic Control Unit (ECU)
AMM 73-21-60-400-001
Installation of the Electronic Control Unit (ECU)
AMM 73-29-00-710-040
Operational Test of the FADEC on the ground (with Engine Motoring)
3. Fault Confirmation
Subtask 73-29-00-710-128-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the operational test of the FADEC 1A and 1B on the ground (with engine non - motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 73-29-00-810-148-A ** ON A/C NOT FOR ALL
A. Do this procedure:
NOTE: This fault is generated if there is an open or short to ground in the torque motor current loop on both channel A and B.
   (1) If the test does not give the maintenance messages J7, HMU(FMV TM), ECU and J8, HMU(FMV TM), ECU:
     (a) If ECAM Warning ENG1 FUEL CTL FAULT was diplayed:
     (b) If ECAM Warning ENG1 FUEL CTL FAULT was not displayed:
  • No further action is required.
   (2) If the test does not give the maintenance messages J7, HMU(FMV TM), ECU and J8, HMU(FMV TM), ECU but are repetitive:
     (a) Replace the ECU [4000KS] , AMM 73-21-60-000-001 and AMM 73-21-60-400-001, if not previously replaced.
       1 Visually examine the J7 and J8 harnesses connectors for damaged pins, contamination AMM 73-21-50-210-001:
         a If damage on a connector is found:
  • replace or repair as required.
         b If nothing is found, continue the troubleshooting.
     (b) replace the HMU-1 [4000KC1] AMM 73-21-10-000-001 and AMM 73-21-10-400-001.
       1 Visually examine the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-001:
         a If damage on a connector is found:
  • replace or repair as required.
         b If fuel wetting is found:
         c If nothing is found, continue the troubleshooting.
     (c) Replace the harness J7 , AMM 73-21-50-000-006 and AMM 73-21-50-400-006.
     (d) Replace the harness J8 , AMM 73-21-50-000-007 and AMM 73-21-50-400-007.
   (3) If the test gives only the maintenance message J7, HMU(FMV TM), ECU (only on channel A).
  • Disconnect the J7 harness from the ECU (4000KS) receptacle and visually examine it and the J7 harness connector for damaged pins, contamination AMM 73-21-50-210-001.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If nothing is found:
  • Do an electrical resistance test through the J7 harness between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • Reconnect the J7 harness to the ECU (4000KS) receptacle, and continue the troubleshooting.
     (c) Disconnect the J7 harness from the HMU receptacle (located left hand core compartment), and visually examine the J7 harness connector and the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-001.
       1 If damage on a connector is found:
  • Replace or repair as required.
       2 If fuel wetting is found:
       3 If nothing is found:
  • Do an electrical resistance test on the HMU receptacle between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
         a If the resistance values are out the specified limits:
         b If the resistance values are in the specified limits:
   (4) If the test gives only the maintenance message J8, HMU(FMV TM), ECU (only on channel B)
  • Disconnect the J8 harness from the ECU (4000KS) receptacle and visually examine it and the J8 harness connector for damaged pins, contamination AMM 73-21-50-210-001.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If nothing is found:
  • Do an electrical resistance test through the J8 harness between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • Reconnect the J8 harness to the ECU (4000KS) receptacle, and continue the troubleshooting.
     (c) Disconnect the J8 harness from the HMU receptacle (located left hand core compartment), and visually examine the J8 harness connector and the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-001.
       1 If damage on a connector is found:
  • Replace or repair as required.
       2 If fuel wetting is found:
       3 If nothing is found:
  • Do an electrical resistance test on the HMU receptacle between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
         a If the resistance values are in the specified limits:
         b If the resistance values are out of the specified limits:
   (5) If the test gives the maintenance messages J7, HMU (FMV TM), ECU + J8, HMU (FMV TM), ECU (on both channel A and B):
     (a) If the fault repeat:
  • Do the troubleshooting described on steps 4.A.(3) and 4.A.(4).
Subtask 73-29-00-810-148-B ** ON A/C NOT FOR ALL
A. Do this procedure:
NOTE: This fault is generated if there is an open or short to ground in the torque motor current loop on both channel A and B.
   (1) If the test does not give the maintenance messages J7, HMU(FMV TM), ECU and J8, HMU(FMV TM), ECU:
     (a) If ECAM Warning ENG1 FUEL CTL FAULT was diplayed:
     (b) If ECAM Warning ENG1 FUEL CTL FAULT was not displayed:
  • No further action is required.
   (2) If the test does not give the maintenance messages J7, HMU(FMV TM), ECU and J8, HMU(FMV TM), ECU but are repetitive:
     (a) Replace the ECU [4000KS] , AMM 73-21-60-000-001 and AMM 73-21-60-400-001, if not previously replaced.
       1 Visually examine the J7 and J8 harnesses connectors for damaged pins, contamination AMM 73-21-50-210-002:
         a If damage on a connector is found:
  • replace or repair as required.
         b If nothing is found, continue the troubleshooting.
     (b) replace the HMU-1 [4000KC1] AMM 73-21-10-000-002 and AMM 73-21-10-400-002.
       1 Visually examine the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-002:
         a If damage on a connector is found:
  • replace or repair as required.
         b If fuel wetting is found:
         c If nothing is found, continue the troubleshooting.
     (c) Replace the harness J7 , AMM 73-21-50-000-040 and AMM 73-21-50-400-040.
     (d) Replace the harness J8 , AMM 73-21-50-000-041 and AMM 73-21-50-400-041.
   (3) If the test gives only the maintenance message J7, HMU(FMV TM), ECU (only on channel A).
  • Disconnect the J7 harness from the ECU (4000KS) receptacle and visually examine it and the J7 harness connector for damaged pins, contamination AMM 73-21-50-210-002.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If nothing is found:
  • Do an electrical resistance test through the J7 harness between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • Reconnect the J7 harness to the ECU (4000KS) receptacle, and continue the troubleshooting.
     (c) Disconnect the J7 harness from the HMU receptacle (located left hand core compartment), and visually examine the J7 harness connector and the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-002.
       1 If damage on a connector is found:
  • Replace or repair as required.
       2 If fuel wetting is found:
       3 If nothing is found:
  • Do an electrical resistance test on the HMU receptacle between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
         a If the resistance values are out the specified limits:
         b If the resistance values are in the specified limits:
   (4) If the test gives only the maintenance message J8, HMU(FMV TM), ECU (only on channel B)
  • Disconnect the J8 harness from the ECU (4000KS) receptacle and visually examine it and the J8 harness connector for damaged pins, contamination AMM 73-21-50-210-002.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If nothing is found:
  • Do an electrical resistance test through the J8 harness between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
       1 If the resistance values are in the specified limits:
       2 If the resistance values are out of the specified limits:
  • Reconnect the J8 harness to the ECU (4000KS) receptacle, and continue the troubleshooting.
     (c) Disconnect the J8 harness from the HMU receptacle (located left hand core compartment), and visually examine the J8 harness connector and the HMU receptacle for damaged pins, contamination and fuel wetting AMM 73-21-50-210-002.
       1 If damage on a connector is found:
  • Replace or repair as required.
       2 If fuel wetting is found:
       3 If nothing is found:
  • Do an electrical resistance test on the HMU receptacle between:
    . pins 27 and 28 (17 to 23 Ohms)
    . pins 27 and 12 (> 10 Megohms)
    . pin 27 and the ground (> 10 Megohms).
         a If the resistance values are in the specified limits:
         b If the resistance values are out of the specified limits:
   (5) If the test gives the maintenance messages J7, HMU (FMV TM), ECU + J8, HMU (FMV TM), ECU (on both channel A and B):
     (a) If the fault repeat:
  • Do the troubleshooting described on steps 4.A.(3) and 4.A.(4).
Subtask 73-29-00-710-129-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.A.(1).
   (1) No additional maintenance action is required if the fault is not confirmed.
   (2) Repeat the fault isolation procedure if the fault continues.
[Rev.8 from Aug 2018] 2026.04.04 04:35:58 UTC
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