Failure of the IGGS Control Unit 1YA

TASK 47-11-00-810-801-A
Failure of the IGGS Control Unit 1YA

1. Possible Causes

IGGS CTL UNIT [1YA]
wiring from IGGS CTL UNIT (1YA) pin A/115 to CSAS CTL UNIT (100HW) pin AB/H11
wiring from IGGS CTL UNIT (1YA) pin A/106 to CSAS CTL UNIT (100HW) pin AB/J11
wiring from IGGS CTL UNIT (1YA) pin A/86 to CSAS CTL UNIT (100HW) pin AB/H12
wiring from IGGS CTL UNIT (1YA) pin A/98 to CSAS CTL UNIT (100HW) pin AB/J12
wiring from IGGS CTL UNIT (1YA) pin A/2 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/3 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/4 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/5 to 103PP (28VDC NORM)
circuit breaker 7YA

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 471101
AMM 47-31-34-000-001	Removal of the IGGS Controller Unit
AMM 47-31-34-400-001	Installation of the IGGS Controller Unit
AMM 47-31-34-740-001	BITE Test of the IGGS with Bleed Air

3. Fault Confirmation
Subtask 47-11-00-740-050-B ** ON A/C NOT FOR ALL

A. Do the subsequent steps to confirm the fault:
(1) On the cockpit rear panel 121VU open, wait for 5 seconds and close the circuit breaker 7YA.
(2) Do the BITE test of the IGGS without bleed air AMM 47-31-34-740-001
(3) If the test comfirms the fault, go to the Para. 4. Fault Isolation.

4. Fault Isolation
Subtask 47-11-00-810-050-B ** ON A/C NOT FOR ALL

A. Procedure
(1) Replace the IGGS CTL UNIT [1YA] AMM 47-31-34-000-001 and AMM 47-31-34-400-001.

On the cockpit rear panel 121VU open, wait for 5 seconds and close the circuit breaker 7YA.
Do the BITE test of the IGGS without bleed air AMM 47-31-34-740-001.

(2) If the fault continues:
(a) Do a check and repair the:

wiring from IGGS CTL UNIT (1YA) pin A/115 to CSAS CTL UNIT (100HW) pin AB/H11
wiring from IGGS CTL UNIT (1YA) pin A/106 to CSAS CTL UNIT (100HW) pin AB/J11
wiring from IGGS CTL UNIT (1YA) pin A/86 to CSAS CTL UNIT (100HW) pin AB/H12
wiring from IGGS CTL UNIT (1YA) pin A/98 to CSAS CTL UNIT (100HW) pin AB/J12
wiring from IGGS CTL UNIT (1YA) pin A/2 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/3 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/4 to 103PP (28VDC NORM)
wiring from IGGS CTL UNIT (1YA) pin A/5 to 103PP (28VDC NORM) ASM 471101.

(b) Do a check and replace the circuit breaker 7YA .

Subtask 47-11-00-740-051-B ** ON A/C NOT FOR ALL

B. Do the test given in para. 3.

NOTE: After the subsequent flight make sure that the fault does not continue.

[Rev.8 from Aug 2018] 2026.04.04 04:34:22 UTC