* Resetting the radio: If you're locked out of the radio due to a forgotten code, you'll need the radio's serial number (usually found on a sticker on the radio itself) and to contact a Cadillac dealer or a car audio specialist to obtain the code.
* Resetting the trip odometer: This is usually done by holding down a button on the instrument cluster (often marked with a small triangle or a zero). Consult your owner's manual for the precise button and procedure.
* Clearing trouble codes (Check Engine light): This requires a diagnostic tool that can read and clear codes from the car's onboard computer (OBD I system). Auto parts stores often offer this service for free. You *cannot* simply reset the Check Engine light by disconnecting the battery; you need to find and fix the underlying problem.
* Resetting the PCM (Powertrain Control Module): This is a more advanced procedure, usually not needed by the average owner. It involves disconnecting the battery for a period of time (often 30 minutes or more) which can cause the computer to revert to its default settings. However, be aware this may reset other settings in the car, such as radio presets and clock. This is generally only done if a technician guides you to do so for a specific issue.
* Resetting other individual systems: Some other functions, such as the seat memory or climate control, might have individual reset procedures. These are usually described in the owner's manual.
In short: To get the specific "reset" you're looking for, you must tell us what exactly you are trying to reset. Then, consulting your owner's manual will likely be the most helpful step. If you don't have the manual, you can usually find a PDF version online by searching for "[Year] Cadillac Deville Owner's Manual."
