Permanent Code

📖 YOUCANIC Automotive Glossary

A permanent code (2010+ vehicles) cannot be cleared by any scan tool, battery disconnect, or manual method. Stored in protected non-volatile memory, it only clears when the ECU’s associated monitor runs and passes under the same conditions that triggered the code. Designed by CARB/EPA to prevent clearing codes before emissions inspections to mask unrepaired problems, ensuring emissions-critical repairs are actually performed.

Permanent codes are accessed through OBD2 Mode $0A. After repairing a fault and clearing active/pending codes, the permanent code remains until you drive through conditions for the related monitor to run and confirm the repair. Do not panic when permanent codes persist — this is by design. Repair the fault, clear what you can, and drive normally for 1-3 drive cycles. If it persists after multiple cycles, the repair may not have fully resolved the issue.