W DOC AIRBUS | TSM A320F

Loss of the feedback signal from the RAC Valve through the two Channels on Engine 2

TASK 75-23-00-810-808-A
Loss of the feedback signal from the RAC Valve through the two Channels on Engine 2

1. Possible Causes
  • ECU [4000KS]
  • harness J11
  • harness J12
  • harness CJ11R
  • harness CJ12R
  • RACC valve
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
AMM 73-21-50-000-002
Removal of the CJ11R Harness
AMM 73-21-50-000-004
Removal of the CJ12R Harness
AMM 73-21-50-000-010
Removal of the J11 Harness
AMM 73-21-50-000-011
Removal of the J12 Harness
AMM 73-21-50-400-002
Installation of the CJ11R Harness
AMM 73-21-50-400-004
Installation of the CJ12R Harness
AMM 73-21-50-400-010
Installation of the J11 Harness
AMM 73-21-50-400-011
Installation of the J12 Harness
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)
ASM 732518
AMM 73-29-00-710-040
Operational Test of the FADEC on the ground (with Engine Motoring)
AMM 75-23-10-000-001
Removal of the Rotor Active Clearance Control (RACC) Valve
AMM 75-23-10-400-001
Installation of the Rotor Active Clearance Control (RACC) Valve
3. Fault Confirmation
Subtask 75-23-00-710-060-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 2A and 2B on the ground (with engine motoring) AMM 73-29-00-710-040.
4. Fault Isolation
Subtask 75-23-00-810-055-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message RAC VLV, J11, ECU and RAC VLV, J12, ECU:
  • do a check for open or short to ground of the harnesses J11 and J12 between the ECU (4000KS) and the 6 o'clock junction box, between the 6 o'clock junction box and the RACC valve ASM 732518.
   (1) If one of these wirings is not correct:
  • repair the defective above wirings.
   (2) If these wirings are correct:
  • disconnect the cables J11 and J12 from the ECU (4000KS) and do a resistance check of the cables J11 and J12 between:
    . pins 40 and 41 (110 to 135 Ohms)
    . pins 20 and 39 (148 to 181 Ohms)
    . pins 8 and 22 (164 to 200 Ohms)
    . pins 40 and 21 (> 10 Megohms)
    . pins 20 and 21 (> 10 Megohms)
    . pins 8 and 21 (> 10 Megohms)
    . pin 40 and the ground (> 10 Megohms)
    . pin 20 and the ground (> 10 Megohms)
    . pin 8 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:
  • disconnect the cables J11 and J12 from the cables CJ11R and CJ12R at the 6 o'clock junction box and do a resistance check of the cables CJ11R and CJ12R between:
    for cable CJ11R
    . pins 3 and 12 (110 to 135 ohms)
    . pins 23 and 24 (148 to 181 ohms)
    . pins 10 and 22 (164 to 200 ohms)
    . pins 3 and 11 (> 10 Megohms)
    . pins 23 and 11 (> 10 Megohms)
    . pins 10 and 11 (> 10 Megohms)
    . pin 3 and the ground (> to Megohms)
    . pin 23 and the ground (> 10 Megohms)
    . pin 10 and the ground (> 10 Megohms)
    for cable CJ12R
    . pins 11 and 24 (110 to 135 ohms)
    . pins 22 and 23 (148 to 181 ohms)
    . pins 9 and 21 (164 to 200 ohms)
    . pins 11 and 10 (> 10 Megohms)
    . pins 22 and 10 (> 10 Megohms)
    . pins 9 and 10 (> 10 Megohms)
    . pin 11 and the ground (> to Megohms)
    . pin 22 and the ground (> 10 Megohms)
    . pin 9 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:
  • disconnect the cables CJ11R and CJ12R from the RACC valve and do a resistance check of the RACC valve between:
    . pins 2 and 3 (122 Ohms + or - 10 %)
    . pins 4 and 5 (165 Ohms + or - 10 %)
    . pins 6 and 7 (182 Ohms + or - 10 %)
    . pin 2 and the ground (> 10 Megohms)
    . pin 4 and the ground (> 10 Megohms)
    . pin 6 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 75-23-00-710-061-A ** ON A/C NOT FOR ALL
B. Do the test given in Para. 3.A.
[Rev.8 from Aug 2018] 2026.04.04 04:37:04 UTC
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