Loss of the feedback Signal from the VSV through the Channel A on Engine 1

TASK 75-32-00-810-805-A
Loss of the feedback Signal from the VSV through the Channel A on Engine 1

1. Possible Causes

harness J11
ECU [4000KS]
harness CJ11R
VSV actuator

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 73-21-50-000-002	Removal of the CJ11R Harness
AMM 73-21-50-000-010	Removal of the J11 Harness
AMM 73-21-50-000-026	Removal of the CJ11R Harness for SAC Engines
AMM 73-21-50-000-044	Removal of the HJ11 Harness for SAC Engines
AMM 73-21-50-400-002	Installation of the CJ11R Harness
AMM 73-21-50-400-010	Installation of the J11 Harness
AMM 73-21-50-400-026	Installation of the CJ11R Harness for SAC Engines
AMM 73-21-50-400-044	Installation of the HJ11 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)
ASM 732518
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)
AMM 75-32-10-000-001	Removal of the Variable Stator Vane (VSV) Actuators
AMM 75-32-10-000-002	Removal of the Variable Stator Vane (VSV) Actuators
AMM 75-32-10-400-001	Installation of the Variable Stator Vane (VSV) Actuators
AMM 75-32-10-400-002	Installation of the Variable Stator Vane (VSV) Actuators

3. Fault Confirmation
Subtask 75-32-00-710-058-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the FADEC 1A on the ground (with engine motoring) AMM 73-29-00-710-040.

4. Fault Isolation
Subtask 75-32-00-810-054-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance message VSV ACT, J11, ECU ENG1A:

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 VSV LVDT ASM 732518.

(1) If the wiring is not correct:

repair the above wiring.

(2) If the wiring is correct:

disconnect the cable J11 from the ECU (4000KS) and do a resistance check of the cable J11 between:
. pins 12 and 28 (400 to 600 Ohms)
. pins 26 and 27 (100 to 180 Ohms)
. pins 10 and 25 (100 to 180 Ohms)
. pins 12 and 11 (> 10 Megohms)
. pins 26 and 11 (> 10 Megohms)
. pins 10 and 11 (> 10 Megohms)
. pin 12 and the ground (> 10 Megohms)
. pin 26 and the ground (> 10 Megohms)
. pin 10 and the ground (> 10 Megohms).

(a) If the resistance values are in the specified limits:

replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

(b) If the resistance values are out of the specified limits:

disconnect the cable J11 from the cable CJ11R at the 6 o'clock junction box and do a resistance check of the cable CJ11R between:
. pins 4 and 14 (400 to 600 Ohms)
. pins 1 and 6 (100 to 180 Ohms)
. pins 15 and 27 (100 to 180 Ohms)
. pins 4 and 5 (> 10 Megohms)
. pins 1 and 5 (> 10 Megohms)
. pins 15 and 5 (> 10 Megohms)
. pin 4 and the ground (> 10 Megohms)
. pin 1 and the ground (> 10 Megohms)
. pin 15 and the ground (> 10 Megohms).

1 If the resistance values are in the specified limits:

replace the harness J11 AMM 73-21-50-000-010 and AMM 73-21-50-400-010.

2 If the resistance values are out of the specified limits:

disconnect the cable CJ11R from the VSV actuator and do a resistance check of the VSV actuator between:
. pins 2 and 3 (400 to 600 Ohms)
. pins 4 and 5 (100 to 180 Ohms)
. pins 6 and 7 (100 to 180 Ohms)
. 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:

replace the harness CJ11R AMM 73-21-50-000-002 and AMM 73-21-50-400-002.

b If the resistance values are out of the specified limits:

replace the VSV actuator AMM 75-32-10-000-001 and AMM 75-32-10-400-001.

Subtask 75-32-00-810-064-A ** ON A/C NOT FOR ALL

B. If the test does note give the maintenance message VSV ACT, J11, ECU ENG1A:

No maintenance action is required.

Subtask 75-32-00-810-054-B ** ON A/C NOT FOR ALL

C. If the test gives the maintenance message VSV ACT, J11, ECU ENG1A:

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 VSV LVDT ASM 732518.

(1) If the wiring is not correct:

repair the above wiring.

(2) If the wiring is correct:

disconnect the cable J11 from the ECU (4000KS) and do a resistance check of the cable J11 between:
. pins 12 and 28 (400 to 600 Ohms)
. pins 26 and 27 (100 to 180 Ohms)
. pins 10 and 25 (100 to 180 Ohms)
. pins 12 and 11 (> 10 Megohms)
. pins 26 and 11 (> 10 Megohms)
. pins 10 and 11 (> 10 Megohms)
. pin 12 and the ground (> 10 Megohms)
. pin 26 and the ground (> 10 Megohms)
. pin 10 and the ground (> 10 Megohms).

(a) If the resistance values are in the specified limits:

replace the ECU [4000KS] AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

(b) If the resistance values are out of the specified limits:

disconnect the cable J11 from the cable CJ11R at the 6 o'clock junction box and do a resistance check of the cable CJ11R between:
. pins 4 and 14 (400 to 600 Ohms)
. pins 1 and 6 (100 to 180 Ohms)
. pins 15 and 27 (100 to 180 Ohms)
. pins 4 and 5 (> 10 Megohms)
. pins 1 and 5 (> 10 Megohms)
. pins 15 and 5 (> 10 Megohms)
. pin 4 and the ground (> 10 Megohms)
. pin 1 and the ground (> 10 Megohms)
. pin 15 and the ground (> 10 Megohms).

1 If the resistance values are in the specified limits:

replace the harness J11 AMM 73-21-50-000-044 and AMM 73-21-50-400-044.

2 If the resistance values are out of the specified limits:

disconnect the cable CJ11R from the VSV actuator and do a resistance check of the VSV actuator between:
. pins 2 and 3 (400 to 600 Ohms)
. pins 4 and 5 (100 to 180 Ohms)
. pins 6 and 7 (100 to 180 Ohms)
. 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:

replace the harness CJ11R AMM 73-21-50-000-026 and AMM 73-21-50-400-026.

b If the resistance values are out of the specified limits:

replace the VSV actuator AMM 75-32-10-000-002 and AMM 75-32-10-400-002.

Subtask 75-32-00-810-064-B ** ON A/C NOT FOR ALL

D. If the test does note give the maintenance message VSV ACT, J11, ECU ENG1A:

No maintenance action is required.

Subtask 75-32-00-710-059-A ** ON A/C NOT FOR ALL

E. Do the test given in Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:37:11 UTC