W DOC AIRBUS | TSM A320F

Loss of the Feedback Signal from the FMV Resolver through the Channel A on Engine 2

TASK 73-29-00-810-866-A
Loss of the Feedback Signal from the FMV Resolver through the Channel A on Engine 2

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 73-21-50-000-040
Removal of the HJ7 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 73-21-50-400-040
Installation of the HJ7 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 73-29-00-710-148-A ** ON A/C NOT FOR ALL
A. Test
   (1) Do the operational test of the FADEC 2A on the ground (with engine non - motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 73-29-00-810-158-A ** ON A/C NOT FOR ALL
A. Do this procedure:
NOTE: This fault is generated if channel A FMV resolver signal is out of range, invalid or the signal disagrees with channel B.
   (1) If the test does not give the maintenance message J7, HMU(FMVRES), ECU:
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If fuel wetting is found:
     (c) If nothing is found:
  • No further action is required.
   (2) If the test does not give the maintenance message J7, HMU(FMVRES), ECU, but is repetitive after the troubleshooting per step 4.A.(1) has been fully done:
     (a) If the fault continues during the subsequent flights:
   (3) If the test gives the maintenance message J7, HMU(FMVRES), ECU:
  • disconnect the J7 harness from the HMU receptacle (HMU-A) (located in the left 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.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If fuel wetting is found:
     (c) If nothing is found:
  • Do an electrical resistance test through the HMU receptacle between:
    . pins 16 and 34 (between 34 and 150 Ohms)
    . pins 35 and 36 (between 21 and 76 Ohms)
    . pins 18 and 37 (between 21 and 76 Ohms)
    . pins 16 and 17 (> 10 Megohms)
    . pins 35 and 17 (> 10 Megohms)
    . pins 18 and 17 (> 10 Megohms)
    . pin 16 and the ground (> 10 Megohms)
    . pin 35 and the ground (> 10 Megohms)
    . pin 18 and the ground (> 10 Megohms).
       1 If the resistance values are out of the specified limits:
       2 If the resistance values are in the specified limits:
     (d) Disconnect the J7 harness from the ECU (4000KS) receptacle and visually examine the J7 harness connector and the ECU (4000KS) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
       1 If damage on a connector is found:
  • replace or repair as required.
       2 If nothing is found:
  • Do an electrical resistance test through the J7 harness between:
    . pins 16 and 34 (between 34 and 150 Ohms)
    . pins 35 and 36 (between 21 and 76 Ohms)
    . pins 18 and 37 (between 21 and 76 Ohms)
    . pins 16 and 17 (> 10 Megohms)
    . pins 35 and 17 (> 10 Megohms)
    . pins 18 and 17 (> 10 Megohms)
    . pin 16 and the ground (> 10 Megohms)
    . pin 35 and the ground (> 10 Megohms)
    . pin 18 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:
Subtask 73-29-00-810-158-B ** ON A/C NOT FOR ALL
A. Do this procedure:
NOTE: This fault is generated if channel A FMV resolver signal is out of range, invalid or the signal disagrees with channel B.
   (1) If the test does not give the maintenance message J7, HMU(FMVRES), ECU:
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If fuel wetting is found:
     (c) If nothing is found:
  • No further action is required.
   (2) If the test does not give the maintenance message J7, HMU(FMVRES), ECU, but is repetitive after the troubleshooting per step 4.A.(1) has been fully done:
     (a) If the fault continues during the subsequent flights:
   (3) If the test gives the maintenance message J7, HMU(FMVRES), ECU:
  • disconnect the J7 harness from the HMU receptacle (HMU-A) (located in the left 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.
     (a) If damage on a connector is found:
  • Replace or repair as required.
     (b) If fuel wetting is found:
     (c) If nothing is found:
  • Do an electrical resistance test through the HMU receptacle between:
    . pins 16 and 34 (between 34 and 150 Ohms)
    . pins 35 and 36 (between 21 and 76 Ohms)
    . pins 18 and 37 (between 21 and 76 Ohms)
    . pins 16 and 17 (> 10 Megohms)
    . pins 35 and 17 (> 10 Megohms)
    . pins 18 and 17 (> 10 Megohms)
    . pin 16 and the ground (> 10 Megohms)
    . pin 35 and the ground (> 10 Megohms)
    . pin 18 and the ground (> 10 Megohms).
       1 If the resistance values are out of the specified limits:
       2 If the resistance values are in the specified limits:
     (d) Disconnect the J7 harness from the ECU (4000KS) receptacle and visually examine the J7 harness connector and the ECU (4000KS) receptacle for damaged pins and contamination AMM 73-21-50-210-002.
       1 If damage on a connector is found:
  • replace or repair as required.
       2 If nothing is found:
  • Do an electrical resistance test through the J7 harness between:
    . pins 16 and 34 (between 34 and 150 Ohms)
    . pins 35 and 36 (between 21 and 76 Ohms)
    . pins 18 and 37 (between 21 and 76 Ohms)
    . pins 16 and 17 (> 10 Megohms)
    . pins 35 and 17 (> 10 Megohms)
    . pins 18 and 17 (> 10 Megohms)
    . pin 16 and the ground (> 10 Megohms)
    . pin 35 and the ground (> 10 Megohms)
    . pin 18 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:
Subtask 73-29-00-710-149-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 04:35:59 UTC
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