* The PCM (Powertrain Control Module): This is the main computer controlling the engine and transmission. There's no simple button to reset it. A true reset usually requires disconnecting the battery's negative terminal for a period of time (30 minutes to an hour is often recommended). This clears the computer's memory, and it will relearn driving patterns and parameters. Caution: Disconnecting the battery may erase radio presets and other settings.
* A specific system's fault codes: If you're experiencing a particular problem (like a check engine light), you might need to have the fault codes read and cleared by a mechanic or using an OBDII scanner. The PCM itself isn't being "reset," but the stored error codes indicating a problem are.
* The radio presets: This is a separate system and not related to the car's main computer. The method for resetting radio presets depends on the specific radio model in your LeSabre. Consult your owner's manual.
In short: To address most likely scenarios, disconnecting the battery negative terminal for 30-60 minutes is the closest thing to a "computer reset" you can perform on a 1997 Buick LeSabre. However, if you are having a specific problem, it's best to consult a mechanic or your owner's manual for a more targeted solution.
