* To reset the onboard computer (ECM/PCM): This clears trouble codes and resets learned parameters like fuel trims. The most common method is to disconnect the negative (-) battery terminal for at least 30 minutes. This allows the computer's memory to completely drain. Reconnect the terminal afterwards.
* To reset the radio: This usually involves a specific code that's provided in your owner's manual. Look for the radio's code or a process described there.
* To reset the trip odometer: Consult your owner's manual. There's typically a button or combination of button presses on the instrument cluster to reset trip odometers (both A and B if equipped).
* If you're experiencing a serious problem (like the car won't start): A "reset" isn't the solution. You'll need to diagnose the issue. This could involve checking the battery, fuses, starter, etc. A mechanic may be necessary.
In short: Disconnecting the negative battery terminal for 30 minutes is the closest thing to a "reset" for most car systems in a 1997 Buick LeSabre. However, make sure you know how to pair any devices connected to the car's systems afterwards (like the radio).
