Loss of the VBV or VSV Torque Motor Control through the Channel B on Engine 1 and Channel A on Engine 2

TASK 73-29-00-810-906-A
Loss of the VBV or VSV Torque Motor Control through the Channel B on Engine 1 and Channel A on Engine 2

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 73-29-00-810-845-A	Loss of the HMU Control Through Channel A on Engine 2
TSM TASK 73-29-00-810-846-A	Loss of the HMU Control Through Channel B on Engine 1
AMM 73-29-00-710-040	Operational Test of the FADEC on the ground (with Engine Motoring)

3. Fault Confirmation
Subtask 73-29-00-710-218-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the FADEC 1B and 2A on the ground (with engine motoring) AMM 73-29-00-710-040.
(2) Read the TROUBLE SHOOTING DATA of the FADEC MENU on the MCDU (Ref. 70-00-00, P. Block 301).

4. Fault Isolation
Subtask 73-29-00-810-198-A ** ON A/C NOT FOR ALL

A. If the test gives the maintenance messages:

J8, HMU, ECU on the channel 1B
and
J7, HMU, ECU on the channel 2A

(1) Do the trouble shooting procedure (Ref. TSM TASK 73-29-00-810-846).
(2) Do the trouble shooting procedure (Ref. TSM TASK 73-29-00-810-845).

[Rev.8 from Aug 2018] 2026.04.04 04:36:02 UTC