W DOC AIRBUS | TSM A320F

VORV Null Shift Bias Channel B

TASK 79-21-00-810-819-A
VORV Null Shift Bias Channel B

1. Possible Causes
2. Job Set-up Information
 A. Fixtures, Tools, Test and Support Equipment
REFERENCE
QTY
DESIGNATION
No specific
1
MULTIMETER - STANDARD
No specific
1
PLIERS - JAWED, SOFT
 B. 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 71-00-00-860-814
Shutdown of the Engine
AMM 71-00-00-860-822
Start the Engine (Normal Manual Start)
AMM 71-00-00-860-823
Start the Engine (Normal Automatic Start)
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 73-21-63-000-802
Removal of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 73-21-63-400-802
Installation of the Electronic Engine Control (EEC) Wiring Harness (W03)
AMM 79-21-15-000-801
Removal of the Variable Oil Reduction Valve (VORV)
AMM 79-21-15-400-801
Installation of the Variable Oil Reduction Valve (VORV)
F EEC Wiring Harnesses
F VORV Wiring Harness
F VORV Wiring Schematic
3. Fault Confirmation
Subtask 79-21-00-710-067-A ** ON A/C NOT FOR ALL
A. Do an engine run to idle to confirm repair of this fault AMM 71-00-00-860-822 or AMM 71-00-00-860-823.
   (1) Shutdown the engine AMM 71-00-00-860-814.
   (2) On Multipurpose Control and Display Unit (MCDU) screen, check if the fault is displayed on ground scanning report.
NOTE: The Electronic Engine Control (EEC) has detected the Variable Oil Flow Reduction Valve (VORV) Torque Motor (TM) requires more current to stay in position in channel B. This fault is usually an indication of a problem with the VORV TM. The VORV has a dual channel TM circuit and a dual channel Linear Variable Differential Transducer (LVDT) circuit. The VORV is mounted aft of the compressor intermediate case firewall, located at the 9 o'clock position.
   (3) If the maintenance message does not come back, examine the harness and electrical connectors as described 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: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE AND ENGINE OIL CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.
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 79-21-00-810-071-A ** ON A/C NOT FOR ALL
A. If there is confirmation of the fault:
   (1) Replace VARIABLE OIL FLOW REDUCTION VALVE [4069KS] AMM 79-21-15-000-801 and AMM 79-21-15-400-801.
     (a) Do the test given in Para. 3.
   (2) If the fault continues:
     (a) Examine the W03 (4087KS) and connector P4 (4000KS-P4) - EEC (4000KS) and connector P54 (4069KS-P54) - VORV (4069KS), for problems which are possible between the EEC (4000KS) and the VORV (4069KS).
     (b) Inspect for harness damage.
     (c) Inspect for loose or damaged connectors.
NOTE: Loose connectors must be disconnected and examined for further wear or damage.
     (d) If a problem is found with the harness or connectors:
       1 Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
       2 Do the test given in Para. 3.
   (3) If no problems are found with the harness or the fault continues, use a PLIERS - JAWED, SOFT to disconnect electrical connector P4 (4000KS-P4) from the EEC (4000KS) and connector P54 (4069KS-P54) from the VORV (4069KS).
     (a) Examine the pins and 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 electrical connector P4 (4000KS-P4) to the EEC (4000KS) and connector P54 (4069KS-P54) to the VORV (4069KS).
     (d) Do the test given in Para. 3.
   (4) If the fault continues:
     (a) Disconnect electrical connector P4 (4000KS-P4) from the EEC (4000KS) and connector P54 (4069KS-P54) from the VORV (4069KS). Use a MULTIMETER - STANDARD to test the VORV (4069KS) TM circuits in the harnesses. Refer to Table 1. Look for:
       1 Wire-to-wire shorts
       2 Shorts to ground
       3 Continuity (less than 5 ohms resistance).
NOTE: A short to ground is found when the resistance is less than 100 000 (100K) ohms.
Table 1: VORV (4069KS) TM Channel B Connector Contacts
W03 (4087KS) Harness P4 (4000KS-P4) EEC (4000KS) Connector Contacts
W03 (4087KS) Harness P54 (4069KS-P54) VORV(4069KS) Connector Contacts
EE
11
MM
12
     (b) If a problem is found with the harnesses or connectors:
       1 Replace W03 HARNESS [4087KS] AMM 73-21-63-000-802 and AMM 73-21-63-400-802.
       2 Do the test given in Para. 3.
   (5) If no problems are found with the harness or the fault continues:
     (a) Replace the [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.
     (b) Do the test given in Para. 3.
5. Close-up
Subtask 79-21-00-860-060-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.
[Rev.8 from Aug 2018] 2026.04.04 04:38:34 UTC
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