Loss of the Zone Controller Data on the ARINC Bus from the EIU to the FADEC on Engine 1
TASK 73-25-00-810-924-A
Loss of the Zone Controller Data on the ARINC Bus from the EIU to the FADEC on Engine 1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
3. Fault Confirmation
Subtask 73-25-00-710-295-A ** ON A/C NOT FOR ALL
Subtask 73-25-00-810-176-A ** ON A/C NOT FOR ALL
[Rev.8 from Aug 2018]
2026.04.04 04:35:49 UTC
Loss of the Zone Controller Data on the ARINC Bus from the EIU to the FADEC on Engine 1
1. Possible Causes
2. Job Set-up Information
A. Referenced Information
| REFERENCE | DESIGNATION |
|---|---|
| AMM 21-61-34-000-002 | Removal of the Air-Conditioning System Controller |
| AMM 21-61-34-400-002 | Installation of the Air-Conditioning System Controller |
| AMM 21-63-34-000-001 | Removal of the Zone Controller |
| AMM 21-63-34-400-001 | Installation of the Zone Controller |
| ASM 732506 | |
| AMM 73-25-34-000-040 | Removal of the Engine Interface Unit (EIU) |
| AMM 73-25-34-400-040 | Installation of the Engine Interface Unit (EIU) |
| AMM 73-25-34-710-040 | Operational Test of the Engine Interface Unit |
| AMM 73-25-34-710-043 | Operational Test of the Engine Interface Unit |
| AMM 73-29-00-710-040 | Operational Test of the FADEC on the ground (with Engine Motoring) |
Subtask 73-25-00-710-295-A ** ON A/C NOT FOR ALL
A. Do the operational test of the FADEC 1 on the ground (with engine non motoring) AMM 73-29-00-710-040.
Subtask 73-25-00-710-295-B ** ON A/C NOT FOR ALL A. Do the operational test of the FADEC 1 on the ground (with engine non motoring) AMM 73-29-00-710-040.
4. Fault IsolationSubtask 73-25-00-810-176-A ** ON A/C NOT FOR ALL
A. If the test gives the maintenance message ZC, EIU (ECSD), J3 or ZNCNT, EIU (ECSD), J3:
Subtask 73-25-00-810-176-C ** ON A/C NOT FOR ALL - do a check for open or short to ground at the pins AA/3J, 3K to pins AA/1J, 2J of the wiring from the the EIU1 to the CONT-ZONE TEMPERATURE (8HK) and at pins AA/2J, 2K to pins AA/1B, 2B of the wiring from the the EIU1 to the CONT-ZONE TEMPERATURE (8HK). ASM 732506.
- repair the defective corresponding wiring.
- do an operational test of the engine interface unit and see if the "NO ZONE CONT DATA" message is shown AMM 73-25-34-710-040.
- replace the ZONE CONTROLLER [8HK] AMM 21-63-34-000-001 and AMM 21-63-34-400-001.
- replace the EIU-1 [1KS1] AMM 73-25-34-000-040 and AMM 73-25-34-400-040.
A. If the test gives the maintenance message ZC, EIU (ECSD), J3:
Subtask 73-25-00-810-176-F ** ON A/C NOT FOR ALL - do a check for open or short to ground at the pins AA/2J, 2K to pins AA/7E, 7F of the wiring from the the EIU1 to the CONT-AIR COND SYSTEM 1 (47HH) and at pins AA/3J, 3K to pins AA/7E, 7F of the wiring from the the EIU1 to the CONT-AIR COND SYSTEM 2 (57HH). ASM 732506.
- repair the defective corresponding wiring.
- do an operational test of the engine interface unit and see if the "NO ZONE CONT DATA" message is shown AMM 73-25-34-710-043.
- replace the CONT-AIR COND SYSTEM 1 [47HH] and CONT-AIR COND SYSTEM 2 [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
- replace the EIU-1 [1KS1] AMM 73-25-34-000-040 and AMM 73-25-34-400-040.
A. If the test gives the maintenance message ZC, EIU (ECSD), J3 or ZNCNT, EIU (ECSD), J3:
Subtask 73-25-00-710-296-A ** ON A/C NOT FOR ALL - do a check for open or short to ground at the pins AA/2J, 2K to pins AA/7E, 7F of the wiring from the the EIU1 to the CONT-AIR COND SYSTEM 1 (47HH) and at pins AA/3J, 3K to pins AA/7E, 7F of the wiring from the the EIU1 to the CONT-AIR COND SYSTEM 2 (57HH). ASM 732506.
- repair the defective corresponding wiring.
- do an operational test of the engine interface unit and see if the "NO ZONE CONT DATA" message is shown AMM 73-25-34-710-040.
- replace the
[47HH] and [57HH] AMM 21-61-34-000-002 and AMM 21-61-34-400-002.
- replace the EIU-1 [1KS1] AMM 73-25-34-000-040 and AMM 73-25-34-400-040.
B. Do the test given in Para. 3.A.