System Latched by Analog Circuit of CCU

TASK 21-58-00-810-819-A
System Latched by Analog Circuit of CCU

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
ASM 215301
AMM 21-58-00-710-001	Operational Test of the Conditioned Service Air System without Bleed Air
AMM 21-58-11-000-001	Removal of the Duct Temperature Sensor
AMM 21-58-11-400-001	Installation of the Duct Temperature Sensor
AMM 21-58-34-000-001	Removal of the CSAS Control Unit
AMM 21-58-34-400-001	Installation of the CSAS Control Unit

3. Fault Confirmation
Subtask 21-58-00-710-086-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the reset procedure for the CSAS and the IGGS as follows,

(2) Do the operational test of the conditioned service air system without bleed air AMM 21-58-00-710-001.

4. Fault Isolation
Subtask 21-58-00-810-068-A ** ON A/C NOT FOR ALL

A. If the test gives a different maintenance message, do the related trouble shooting procedure.

Subtask 21-58-00-810-070-A ** ON A/C NOT FOR ALL

B. If the test gives the maintenance message SYS LATCHED BY ANALOG CIRCUIT OF CCU:
(1) Do the reset procedure for the CSAS and the IGGS as follows,

(2) If the fault continues:

(3) If the fault continues:

(4) If the fault continues:

do a check and repair the wiring from:
the CSAS TEMPERATURE SENSOR (115HW) to the CSAS CONTROL UNIT (100HW) and,
the CSAS TEMPERATURE SENSOR (115HW) to ground ASM 215301.

Subtask 21-58-00-710-087-A ** ON A/C NOT FOR ALL

C. Do the test as given in the Para. 3.A.

[Rev.8 from Aug 2018] 2026.04.04 04:24:50 UTC