Posted on 11/28/2025
Unplugging the battery to clear a check engine light sounds simple. Sometimes the light goes out for a short time. But most of the time it returns, and you may create new problems like lost radio presets, failed emissions readiness, or a rough idle. Here is what actually happens when you remove power, what resets, what does not, and the smarter way to fix the light for good. What The Light Tracks The check engine light turns on when the engine computer stores a fault that affects emissions or reliability. It also saves freeze-frame data showing operating conditions at the moment of the fault. Disconnecting the battery can erase that memory, but it does not repair the issue that triggered the code in the first place. Will Battery Disconnect Clear the Light? It might, temporarily. Pulling power can wipe stored codes on some vehicles, especially old ... read more