Data Storage Unit Plug Failure

TASK 73-21-00-810-881-A
Data Storage Unit Plug Failure

1. Possible Causes

[4000KS]
DATA STORAGE UNIT [4670KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 71-00-00-810-834-A	General Troubleshooting Guidelines for Additional Troubleshooting Information
TSM TASK 71-00-00-810-835-A	Component and Harness Intermittent Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults
AMM 70-70-00-910-803	SPOP 6 - Cleaning of the Contact Points and Wiring Harnesses
AMM 71-13-00-010-802	Opening of the Fan Cowl Doors
AMM 71-13-00-410-802	Closing of the Fan Cowl Doors
AMM 73-21-01-000-801	Removal of the Electronic Engine Control (EEC)
AMM 73-21-01-400-801	Installation of the Electronic Engine Control (EEC)
AMM 73-21-02-000-801	Removal of the Data Storage Unit (DSU)
AMM 73-21-02-400-801	Installation of the Data Storage Unit (DSU)
EEC Wiring Harnesses

3. Fault Confirmation
Subtask 73-21-00-710-132-A ** ON A/C NOT FOR ALL

A. Energize the FADEC of the engine that has a fault report.
(1) On the ENG section of maintenance panel 50VU:
(a) Release the FADEC GND PWR/1(2) pushbutton switch (the ON legend comes on).

NOTE: After the FADEC is energized, wait ten seconds before you start the test. If you do not wait ten seconds, the interactive mode stops the EEC self-test and this can cause spurious faults.

(2) On MCDU screen, make sure that the fault is not displayed on ground scanning report.

NOTE: The Electronic Engine Control (EEC) has detected the circuits for the data storage unit has failed in channel A or channel B. The data storage unit is mounted on the EEC.

Refer to the general troubleshooting guidelines for additional troubleshooting information (Ref. TSM TASK 71-00-00-810-834).
Refer to the component and harness intermittent troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-835).

(3) If the maintenance message does not come back, examine the data storage unit to EEC connector as describe in the component and harness intermittent fault isolation procedure (Ref. TSM TASK 71-00-00-810-835).
(a) If no problems are found, return the engine to service. Monitor the engine for reoccurring maintenance message.
(4) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.

4. Fault Isolation

WARNING: REFER TO THE MSDS FOR ALL MATERIAL USED AND THE MANUFACTURER'S SAFETY INSTRUCTIONS FOR ALL EQUIPMENT USED. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

CAUTION: MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.

Subtask 73-21-00-810-153-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Open the fan cowl-doors AMM 71-13-00-010-802.
(2) Check the data storage unit (4670KS) for looseness and condition.
(3) Disconnect the data storage unit (4670KS) from the EEC (4000KS).
(a) Examine the pins, sockets (contacts) for alignment and damage. Look for contacts pushed rearward into the connector face. Replace parts as necessary.
(b) Clean the contacts with contact cleaner and clean cloth per SPOP 6. Blow dry with air (at less than 30 psi) across the connector face AMM 70-70-00-910-803.
(c) Reconnect the data storage unit (4670KS) to the EEC (4000KS).
(d) Do the test given in Para. 3.
(4) If the fault continues:
(a) Replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
(b) Do the test given in Para. 3.
(5) If the fault continues:
(a) Replace DATA STORAGE UNIT [4670KS] AMM 73-21-02-000-801 and AMM 73-21-02-400-801.
(b) Do the test given in Para. 3.

5. Close-up
Subtask 73-21-00-860-073-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the fan cowl-doors AMM 71-13-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:40:57 UTC