W DOC AIRBUS | TSM A320F

Loss of the Feedback Signal from the LPTC Valve - Engine 2 - Channel B

TASK 75-22-00-810-804-A
Loss of the Feedback Signal from the LPTC Valve - Engine 2 - Channel B

1. Possible Causes
  • LPTC valve
  • ECU [4000KS]
  • harness J12
  • harness CJ12R
  • harness HJ12
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-50-000-004
Removal of the CJ12R Harness
AMM 73-21-50-000-011
Removal of the J12 Harness
AMM 73-21-50-000-028
Removal of the CJ12R Harness for SAC Engines
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 73-21-50-210-002
Visual Inspection of the Wiring Harnesses
AMM 73-21-50-400-004
Installation of the CJ12R Harness
AMM 73-21-50-400-011
Installation of the J12 Harness
AMM 73-21-50-400-028
Installation of the CJ12R Harness for SAC Engines
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 75-22-10-000-001
Removal of the Low Pressure Turbine Active Clearance Control Valve (LPTACC).
AMM 75-22-10-000-002
Removal of the Low Pressure Turbine Active Clearance Control (LPTACC) Valve
AMM 75-22-10-400-001
Installation of the Low Pressure Turbine Active Clearance Control Valve (LPTACC).
AMM 75-22-10-400-002
Installation of the Low Pressure Turbine Active Clearance Control (LPTACC) Valve
3. Fault Confirmation
Subtask 75-22-00-710-056-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 2B on the ground (with engine motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 75-22-00-810-053-A ** ON A/C NOT FOR ALL
A. The fault message is generated if the channel B signal is invalid, out of range.
   (1) If the failure message LPTC VLV, J12, ECU is not confirmed:
     (a) No maintenance action is required.
   (2) If the failure message LPTC VLV, J12, ECU is not confirmed but is repetitive:
  • Disconnect the CJ12R harness (LPT-B) connector (located in the right core compartment) from the LPTC valve and visually examine the receptacles and the connectors for damaged pins or contamination AMM 73-21-50-210-001.
     (a) If damage is found:
  • Repair or replace as required.
     (b) If no damage is found:
     (c) If the fault continues during the subsequent flights:
     (d) If the fault continues during the subsequent flights:
     (e) If the fault continues during the subsequent flights:
   (3) If the failure message LPTC VLV, J12, ECU is confirmed:
  • Disconnect the CJ12R harness (LPT-B) connector (located in the right core compartment) from the LPTC valve and visually examine the CJ12R wire harness connector receptacles and the LPTC valve connectors for damaged pins or 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 LPTC valve between:
    . Pins 2 and 3 (80 to 109.5 ohms)
    . Pins 4 and 5 (85 to 115 ohms)
    . Pins 6 and 7 (85 to 115 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 values are out of the specified limits:
     (d) If the resistance values are in the specified limits:
  • Reconnect the CJ12R harness (LPT-B) connector to the LPTC valve,
  • Disconnect the J12 harness (channel B) from the ECU (4000KS) and visually examine the receptacle for damaged pins or contamination AMM 73-21-50-210-001.
       1 If damage is found:
  • Repair or replace as required.
       2 If no damage is found:
  • Do an electrical resistance test through the J12 harness between:
    . Pins 4 and 5 (80 to 109.5 ohms)
    . Pins 6 and 7 (85 to 115 ohms)
    . Pins 2 and 3 (85 to 115 ohms)
    . Pins 4 and 1 (> 10 megohms)
    . Pins 6 and 1 (> 10 megohms)
    . Pins 2 and 1 (> 10 megohms)
    . Pin 4 and the ground (> 10 megohms)
    . Pin 6 and the ground (> 10 megohms)
    . Pin 2 and the ground (> 10 megohms).
       3 If the resistance values are in the specified limits:
       4 If the resistance values are out of the specified limits:
  • Disconnect the J12 harness from the CJ12R harness located at the 6 o'clock junction box and do an electrical resistance test through the CJ12R harness between:
    . Pins 14 and 13 (80 to 109.5 ohms)
    . Pins 12 and 3 (85 to 115 ohms)
    . Pins 2 and 1 (85 to 115 ohms)
    . Pins 14 and 4 (> 10 megohms)
    . Pins 12 and 4 (> 10 megohms)
    . Pins 2 and 4 (> 10 megohms)
    . Pin 14 and the ground (> 10 megohms)
    . Pin 12 and the ground (> 10 megohms)
    . Pin 2 and the ground (> 10 megohms).
       5 If the resistance values are in the specified limits:
       6 If the resistance values are out of the specified limits:
Subtask 75-22-00-810-053-B ** ON A/C NOT FOR ALL
A. The fault message is generated if the channel B signal is invalid, out of range.
   (1) If the failure message LPTC VLV, J12, ECU is not confirmed:
     (a) No maintenance action is required.
   (2) If the failure message LPTC VLV, J12, ECU is not confirmed but is repetitive:
  • Disconnect the CJ12R harness (LPT-B) connector (located in the right core compartment) from the LPTC valve and visually examine the receptacles and the connectors for damaged pins or contamination AMM 73-21-50-210-002.
     (a) If damage is found:
  • Repair or replace as required.
     (b) If no damage is found:
     (c) If the fault continues during the subsequent flights:
     (d) If the fault continues during the subsequent flights:
     (e) If the fault continues during the subsequent flights:
   (3) If the failure message LPTC VLV, J12, ECU is confirmed:
  • Disconnect the CJ12R harness (LPT-B) connector (located in the right core compartment) from the LPTC valve and visually examine the CJ12R wire harness connector receptacles and the LPTC valve connectors for damaged pins or contamination AMM 73-21-50-210-002.
     (a) If damage is found:
  • Repair or replace as required.
     (b) If no damage is found:
  • Do an electrical resistance test through the LPTC valve between:
    . Pins 2 and 3 (80 to 109.5 ohms)
    . Pins 4 and 5 (85 to 115 ohms)
    . Pins 6 and 7 (85 to 115 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 values are out of the specified limits:
     (d) If the resistance values are in the specified limits:
  • Reconnect the CJ12R harness (LPT-B) connector to the LPTC valve,
  • Disconnect the HJ12 harness (channel B) from the ECU (4000KS) and visually examine the receptacle for damaged pins or contamination AMM 73-21-50-210-002.
       1 If damage is found:
  • Repair or replace as required.
       2 If no damage is found:
  • Do an electrical resistance test through the HJ12 harness between:
    . Pins 4 and 5 (80 to 109.5 ohms)
    . Pins 6 and 7 (85 to 115 ohms)
    . Pins 2 and 3 (85 to 115 ohms)
    . Pins 4 and 1 (> 10 megohms)
    . Pins 6 and 1 (> 10 megohms)
    . Pins 2 and 1 (> 10 megohms)
    . Pin 4 and the ground (> 10 megohms)
    . Pin 6 and the ground (> 10 megohms)
    . Pin 2 and the ground (> 10 megohms).
       3 If the resistance values are in the specified limits:
       4 If the resistance values are out of the specified limits:
  • Disconnect the HJ12 harness from the CJ12R harness located at the 6 o'clock junction box and do an electrical resistance test through the CJ12R harness between:
    . Pins 14 and 13 (80 to 109.5 ohms)
    . Pins 12 and 3 (85 to 115 ohms)
    . Pins 2 and 1 (85 to 115 ohms)
    . Pins 14 and 4 (> 10 megohms)
    . Pins 12 and 4 (> 10 megohms)
    . Pins 2 and 4 (> 10 megohms)
    . Pin 14 and the ground (> 10 megohms)
    . Pin 12 and the ground (> 10 megohms)
    . Pin 2 and the ground (> 10 megohms).
       5 If the resistance values are in the specified limits:
       6 If the resistance values are out of the specified limits:
Subtask 75-22-00-710-057-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 04:37:02 UTC
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