A320
Maintenance Airframe; Maintenance Powerplant
Confusion; Troubleshooting; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Human Factors; Aircraft; Procedure
Upon aircraft returning for reoccuring high stage valve bleed message; proceeded to perform MEL procedure XX-XX-S for #1 engine. Proceeded to lock out high stage valve. Closed up #1 engine and aircraft was released and departed. Received call from Maintenance Control asking if I had inoped high stage valve. I started to investigate further; at which point I realized I had locked out the intermediate valve. I immediately contacted Maintenance Control and informed them I had locked out the wrong valve. Maintenance Control said they would be notifying ZZZ Maintenance when aircraft arrives.
Technician reported locking out the intermediate bleed valve instead of the high stage bleed valve while applying MEL.