TO/GA Inputs Invalid on Engine 1

TASK 77-00-00-810-910-A
TO/GA Inputs Invalid on Engine 1

1. Possible Causes

P0 port on the ECU
PS12 sense line
LGCIU-1 [5GA1]
EIU-1 [1KS1]
ECU [4000KS]
ADIRU 1
ADIRU 2

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 73-25-00-810-916-A	Loss of Weight on Wheels Signal on the System 1
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)

3. Fault Confirmation
Subtask 77-00-00-710-273-A ** ON A/C NOT FOR ALL

A. Test
(1) The fault cannot be confirmed by the ground test.

4. Fault Isolation
Subtask 77-00-00-810-194-A ** ON A/C NOT FOR ALL

A. This failure message will be set if the ECU cannot determine the take-off or go around state due to disagreement on flight/ground input signals.
(1) If the failure message ADC1+ADC2+LGCIU1 is displayed:

look at the Post Flight Report or the Last Leg Report for failure message EIU, LGCIU (WOW).

(a) If there is this message:

do the applicable trouble shooting procedure for this message (Ref. TSM TASK 73-25-00-810-916).

1 The fault may be caused by:

a blockage of the P0 port on the ECU ,
a blockage or leakage on the PS12 sense line ,
an LGCIU-1 [5GA1] system failure,
an EIU-1 [1KS1] or an ECU [4000KS] internal failure.

(b) If there is not this message:

look for failure message relative to ADIRU 1 or ADIRU 2 or pitot or static probes.

1 If there is a message:

do the applicable trouble shooting procedure.

2 If there is no message:

replace the ECU (4000KS) AMM 73-21-60-000-001 and AMM 73-21-60-400-001.

Subtask 77-00-00-710-274-A ** ON A/C NOT FOR ALL

B. No additional maintenance action is required if the fault is not confirmed.
(1) Repeat the fault isolation procedure if the fault continues.

[Rev.8 from Aug 2018] 2026.04.04 04:37:35 UTC