W DOC AIRBUS | TSM A320F

Loss of the VBV Feedback Signal - Engine 1 - Channel B

TASK 75-30-00-810-815-A
Loss of the VBV Feedback Signal - Engine 1 - Channel B

1. Possible Causes
  • VBV sensor (RVDT)
  • ECU [4000KS]
  • harness J12
  • harness CJ12L
  • harness HJ12
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-50-000-003
Removal of the CJ12L Harness
AMM 73-21-50-000-011
Removal of the J12 Harness
AMM 73-21-50-000-027
Removal of the CJ12L Harness
AMM 73-21-50-000-045
Removal of the HJ12 Harness for SAC Engines
AMM 73-21-50-210-001
Visual Inspection of the Wiring Harness
AMM 73-21-50-400-003
Installation of the CJ12L Harness
AMM 73-21-50-400-011
Installation of the J12 Harness
AMM 73-21-50-400-027
Installation of the CJ12L Harness
AMM 73-21-50-400-045
Installation of the HJ12 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)
AMM 75-31-00-200-001
Manual Operation Check of the Variable Bleed Valve Doors
AMM 75-31-00-200-002
Manual Operation Check of the Variable Bleed Valve Doors
AMM 75-31-70-000-001
Removal of the Variable Bleed Valve Position Sensor
AMM 75-31-70-000-002
Removal of the Variable Bleed Valve position Sensor
AMM 75-31-70-400-001
Installation of the Variable Bleed Valve Position Sensor
AMM 75-31-70-400-002
Installation of the Variable Bleed Valve position Sensor
3. Fault Confirmation
Subtask 75-30-00-710-080-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 1B on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 75-30-00-810-065-A ** ON A/C NOT FOR ALL
A. The failure message is generated if the channel B signal is invalid, out of range, or both channels disagree.
   (1) If the failure message VBV SENS, J12, ECU is not confirmed:
     (a) No maintenance action is required.
   (2) If the failure message VBV SENS, J12, ECU is not confirmed but is repetitive:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the receptacle and the harness for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
NOTE: After new VBV sensor is installed, a rigging of the VBV system is required AMM 75-31-00-200-001.
     (c) If the fault continues during the subsequent flights:
  • disconnect the J12 harness from the ECU (4000KS) and visually examine the receptacle and the connector for damaged pins and contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair or replace as required.
       2 If no damage is found:
     (d) if the fault continues during the subsequent flights:
     (e) If the fault continues during the subsequent flights:
   (3) If the failure message VBV SENS, J12, ECU is confirmed:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the CJ12L harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
  • do an electrical resistance test through the VBV sensor between:
    . pins 2 and 3 (80 to 110 ohms)
    . pins 4 and 5 (80 to 120 ohms)
    . pins 6 and 7 (85 to 120 ohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 4 and the ground (> 10 megohms)
    . pin 6 and the ground (> 10 megohms).
     (c) If the resistance test values are out of the specified limits:
     (d) If the resistance test values are in the specified limits:
  • reconnect the harness CJ12L (VBV-B connector) to the VBV sensor (RVDT),
  • disconnect the harness J12 from the ECU (4000KS) receptacle and visually examine the J12 harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (e) If damage is found:
  • repair or replace as required.
     (f) If no damage is found:
  • do an electrical resistance test through the J12 harness between:
    . pins 13 and 29 (80 to 110 ohms)
    . pins 30 and 31 (80 to 120 ohms)
    . pins 15 and 32 (85 to 120 ohms)
    . pins 13 and 14 (> 10 megohms)
    . pins 30 and 14 (> 10 megohms)
    . pins 15 and 14 (> 10 megohms)
    . pin 13 and the ground (> 10 megohms)
    . pin 30 and the ground (> 10 megohms)
    . pin 15 and the ground (> 10 megohms).
     (g) If the resistance test values are in the specified limits:
     (h) If the resistance test values are out of the specified limits:
  • disconnect the J12 harness (located at the 6 o'clock junction box) from the CJ12L and do an electrical resistance test through the CJ12L harness between:
    . pins 5 and 6 (80 to 110 ohms)
    . pins 2 and 7 (80 to 120 ohms)
    . pins 3 and 4 (85 to 120 ohms)
    . pins 5 and 1 (> 10 megohms)
    . pins 2 and 1 (> 10 megohms)
    . pins 3 and 1 (> 10 megohms)
    . pin 5 and the ground (> 10 megohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 3 and the ground (> 10 megohms).
     (i) If the resistance test values are out of the specified limits:
     (j) If the resistance test values are in the specified limits:
Subtask 75-30-00-810-065-B ** ON A/C NOT FOR ALL
A. The failure message is generated if the channel B signal is invalid, out of range, or both channels disagree.
   (1) If the failure message VBV SNSR, J12, ECU is not confirmed:
     (a) No maintenance action is required.
   (2) If the failure message VBV SENS, J12, ECU is not confirmed but is repetitive:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the receptacle and the harness for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
NOTE: After new VBV sensor is installed, a rigging of the VBV system is required AMM 75-31-00-200-001.
     (c) If the fault continues during the subsequent flights:
  • disconnect the J12 harness from the ECU (4000KS) and visually examine the receptacle and the connector for damaged pins and contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair or replace as required.
       2 If no damage is found:
     (d) If the fault continues during the subsequent flights:
     (e) If the fault continues during the subsequent flights:
   (3) If the failure message VBV SENS, J12, ECU is confirmed:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the CJ12L harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
  • do an electrical resistance test through the VBV sensor between:
    . pins 2 and 3 (80 to 110 ohms)
    . pins 4 and 5 (80 to 120 ohms)
    . pins 6 and 7 (85 to 120 ohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 4 and the ground (> 10 megohms)
    . pin 6 and the ground (> 10 megohms).
     (c) If the resistance test values are out of the specified limits:
     (d) If the resistance test values are in the specified limits:
  • reconnect the harness CJ12L (VBV-B connector) to the VBV sensor (RVDT),
  • disconnect the harness J12 from the ECU (4000KS) receptacle and visually examine the J12 harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (e) If damage is found:
  • repair or replace as required.
     (f) If no damage is found:
  • do an electrical resistance test through the J12 harness between:
    . pins 13 and 29 (80 to 110 ohms)
    . pins 30 and 31 (80 to 120 ohms)
    . pins 15 and 32 (85 to 120 ohms)
    . pins 13 and 14 (> 10 megohms)
    . pins 30 and 14 (> 10 megohms)
    . pins 15 and 14 (> 10 megohms)
    . pin 13 and the ground (> 10 megohms)
    . pin 30 and the ground (> 10 megohms)
    . pin 15 and the ground (> 10 megohms).
     (g) If the resistance test values are in the specified limits:
     (h) If the resistance test values are out of the specified limits:
  • disconnect the J12 harness (located at the 6 o'clock junction box) from the CJ12L and do an electrical resistance test through the CJ12L harness between:
    . pins 5 and 6 (80 to 110 ohms)
    . pins 2 and 7 (80 to 120 ohms)
    . pins 3 and 4 (85 to 120 ohms)
    . pins 5 and 1 (> 10 megohms)
    . pins 2 and 1 (> 10 megohms)
    . pins 3 and 1 (> 10 megohms)
    . pin 5 and the ground (> 10 megohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 3 and the ground (> 10 megohms).
     (i) If the resistance test values are out of the specified limits:
     (j) If the resistance test values are in the specified limits:
Subtask 75-30-00-810-065-C ** ON A/C NOT FOR ALL
A. The failure message is generated if the channel B signal is invalid, out of range, or both channels disagree.
   (1) If the failure message VBV SNSR, J12, ECU is not confirmed:
     (a) No maintenance action is required.
   (2) If the failure message VBV SENS, J12, ECU is not confirmed but is repetitive:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the receptacle and the harness for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
NOTE: After new VBV sensor is installed, a rigging of the VBV system is required AMM 75-31-00-200-002.
     (c) If the fault continues during the subsequent flights:
  • disconnect the HJ12 harness from the ECU (4000KS) and visually examine the receptacle and the connector for damaged pins and contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • repair or replace as required.
       2 If no damage is found:
     (d) If the fault continues during the subsequent flights:
     (e) If the fault continues during the subsequent flights:
   (3) If the failure message VBV SENS, J12, ECU is confirmed:
  • disconnect the CJ12L harness from the VBV sensor (VBV-B connector) located in the left core compartment and visually examine the CJ12L harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • repair or replace as required.
     (b) If no damage is found:
  • do an electrical resistance test through the VBV sensor between:
    . pins 2 and 3 (80 to 110 ohms)
    . pins 4 and 5 (80 to 120 ohms)
    . pins 6 and 7 (85 to 120 ohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 4 and the ground (> 10 megohms)
    . pin 6 and the ground (> 10 megohms).
     (c) If the resistance test values are out of the specified limits:
     (d) If the resistance test values are in the specified limits:
  • reconnect the harness CJ12L (VBV-B connector) to the VBV sensor (RVDT),
  • disconnect the harness HJ12 from the ECU (4000KS) receptacle and visually examine the HJ12 harness connector and the VBV sensor (RVDT) receptacle for damaged pins and contamination AMM 73-21-50-210-001.
     (e) If damage is found:
  • repair or replace as required.
     (f) If no damage is found:
  • do an electrical resistance test through the HJ12 harness between:
    . pins 13 and 29 (80 to 110 ohms)
    . pins 30 and 31 (80 to 120 ohms)
    . pins 15 and 32 (85 to 120 ohms)
    . pins 13 and 14 (> 10 megohms)
    . pins 30 and 14 (> 10 megohms)
    . pins 15 and 14 (> 10 megohms)
    . pin 13 and the ground (> 10 megohms)
    . pin 30 and the ground (> 10 megohms)
    . pin 15 and the ground (> 10 megohms).
     (g) If the resistance test values are in the specified limits:
     (h) If the resistance test values are out of the specified limits:
  • disconnect the HJ12 harness (located at the 6 o'clock junction box) from the CJ12L and do an electrical resistance test through the CJ12L harness between:
    . pins 5 and 6 (80 to 110 ohms)
    . pins 2 and 7 (80 to 120 ohms)
    . pins 3 and 4 (85 to 120 ohms)
    . pins 5 and 1 (> 10 megohms)
    . pins 2 and 1 (> 10 megohms)
    . pins 3 and 1 (> 10 megohms)
    . pin 5 and the ground (> 10 megohms)
    . pin 2 and the ground (> 10 megohms)
    . pin 3 and the ground (> 10 megohms).
     (i) If the resistance test values are out of the specified limits:
     (j) If the resistance test values are in the specified limits:
Subtask 75-30-00-710-081-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.A.
   (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 04:37:08 UTC
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