Loss of the feedback Signal from the VSV through the two Channels on Engine 2

TASK 75-32-00-810-804-A
Loss of the feedback Signal from the VSV through the two Channels on Engine 2

1. Possible Causes

ECU [4000KS]
harness J11
harness J12
harness CJ11R
harness CJ12L
VSV actuator

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 73-21-50-000-002	Removal of the CJ11R Harness
AMM 73-21-50-000-003	Removal of the CJ12L Harness
AMM 73-21-50-000-010	Removal of the J11 Harness
AMM 73-21-50-000-011	Removal of the J12 Harness
AMM 73-21-50-000-026	Removal of the CJ11R Harness for SAC Engines
AMM 73-21-50-000-027	Removal of the CJ12L Harness
AMM 73-21-50-000-044	Removal of the HJ11 Harness for SAC Engines
AMM 73-21-50-000-045	Removal of the HJ12 Harness for SAC Engines
AMM 73-21-50-400-002	Installation of the CJ11R Harness
AMM 73-21-50-400-003	Installation of the CJ12L Harness
AMM 73-21-50-400-010	Installation of the J11 Harness
AMM 73-21-50-400-011	Installation of the J12 Harness
AMM 73-21-50-400-026	Installation of the CJ11R Harness for SAC Engines
AMM 73-21-50-400-027	Installation of the CJ12L Harness
AMM 73-21-50-400-044	Installation of the HJ11 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)
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 75-32-00-710-056-A ** ON A/C NOT FOR ALL

A. Test
(1) 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 75-32-00-810-053-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance messages VSV ACT, J11, ECU and VSV ACT, 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 VSV LVDT ASM 732518.

(1) If one of these wirings is not correct:

repair the defective wiring.

(2) If these wirings are correct:

disconnect the cables J11 (Channel A) and J12 (Channel B) from the ECU (4000KS) and do a resistance check of the cables J11 and J12 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 cables J11 and J12 from the cables CJ11R and CJ12L at the 6 o'clock junction box and do a resistance check of the cables CJ11R and CJ12L between:
For cable CJ11R
. 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).
for cable CJ12L
. pins 24 and 11 (400 to 600 Ohms)
. pins 23 and 22 (100 to 180 Ohms)
. pins 21 and 9 (100 to 180 Ohms)
. pins 24 and 10 (> 10 Megohms)
. pins 23 and 10 (> 10 Megohms)
. pins 21 and 10 (> 10 Megohms)
. pin 24 and the ground (> 10 Megohms)
. pin 23 and the ground (> 10 Megohms)
. pin 21 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 or harness J12 AMM 73-21-50-000-011 and AMM 73-21-50-400-011.

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

disconnect the cables CJ11R and CJ12L 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 or the harness CJ12L AMM 73-21-50-000-003 and AMM 73-21-50-400-003.

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 75-32-00-810-063-A ** ON A/C NOT FOR ALL

B. If the test does not give the maintenance messages VSV ACT, J11, ECU and VSV ACT, J12, ECU:

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

Subtask 75-32-00-810-053-B ** ON A/C NOT FOR ALL

C. If the test gives the maintenance messages VSV ACT, J11, ECU and VSV ACT, 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 VSV LVDT ASM 732518.

(1) If one of these wirings is not correct:

repair the defective wiring.

(2) If these wirings are correct:

disconnect the cables J11 (Channel A) and J12 (Channel B) from the ECU (4000KS) and do a resistance check of the cables J11 and J12 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 cables J11 and J12 from the cables CJ11R and CJ12L at the 6 o'clock junction box and do a resistance check of the cables CJ11R and CJ12L between:
For cable CJ11R
. 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).
for cable CJ12L
. pins 24 and 11 (400 to 600 Ohms)
. pins 23 and 22 (100 to 180 Ohms)
. pins 21 and 9 (100 to 180 Ohms)
. pins 24 and 10 (> 10 Megohms)
. pins 23 and 10 (> 10 Megohms)
. pins 21 and 10 (> 10 Megohms)
. pin 24 and the ground (> 10 Megohms)
. pin 23 and the ground (> 10 Megohms)
. pin 21 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 or harness J12 AMM 73-21-50-000-045 and AMM 73-21-50-400-045.

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

disconnect the cables CJ11R and CJ12L 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 or the harness CJ12L AMM 73-21-50-000-027 and AMM 73-21-50-400-027.

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 75-32-00-810-063-B ** ON A/C NOT FOR ALL

D. If the test does not give the maintenance messages VSV ACT, J11, ECU and VSV ACT, J12, ECU:

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

Subtask 75-32-00-710-057-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