Loss of the feedback signal from the RAC Valve through the Channel A on Engine 2
TASK 75-23-00-810-810-A
Loss of the feedback signal from the RAC Valve through the Channel A on Engine 2
1. Possible Causes
A. Referenced Information
3. Fault Confirmation
Subtask 75-23-00-710-064-A ** ON A/C NOT FOR ALL
Subtask 75-23-00-810-057-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:37:04 UTC
Loss of the feedback signal from the RAC Valve through the Channel A on Engine 2
1. Possible Causes
- harness J11
- ECU [4000KS]
- harness CJ11R
- RACC valve
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 73-21-50-000-002 | Removal of the CJ11R Harness |
| AMM 73-21-50-000-010 | Removal of the J11 Harness |
| AMM 73-21-50-400-002 | Installation of the CJ11R Harness |
| AMM 73-21-50-400-010 | Installation of the J11 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 |
Subtask 75-23-00-710-064-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 2A on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault IsolationSubtask 75-23-00-810-057-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message RAC VLV, J11, ECU:
Subtask 75-23-00-710-065-A ** ON A/C NOT FOR ALL - do a check for open or short to ground of the harness J11 between the ECU (4000KS) and the 6 o'clock junction box, between the 6 o'clock junction box and the RACC valve ASM 732518.
- repair the above wiring.
- disconnect the cable J11 (channel A) from the ECU (4000KS) and do a resistance check of the cable J11 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).
- replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.
- disconnect the cable J11 (channel A) from the cable CJ11R at the 6 o'clock junction box and do a resistance check of the cable CJ11R between:
. pins 3 and 12 (110 to 130 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).
- replace the harness J11 AMM 73-21-50-000-010 and AMM 73-21-50-400-010.
- disconnect the cable CJ11R 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).
- replace the harness CJ11R AMM 73-21-50-000-002 and AMM 73-21-50-400-002.
- replace the RACC valve AMM 75-23-10-000-001 and AMM 75-23-10-400-001.
B. Do the test given in Para. 3.A.