Grab a 9 volt battery, pop it in your hand tool and get going! This is a user-friendly and effective way to reset the TPMS settings for each wheel assembly's position after changing tires. If you don't reset the TPMS or your tire dealer forgets to reset the TPMS, you will get a DIC reading showing the tire pressure for each tire in the wrong location on your vehicle. The hardest part of resetting is getting (easily) into your car's "Reset" area on the DIC. Follow the manual, use the tool and bingo, the reset is correct and done! Most vehicles start at the driver's front wheel and move clockwise around the vehicle (from the driver's seat). On GM vehicles, a cornering light will illuminate to indicate the next tire needs to be reset and beep when this is recorded. Keep moving clockwise around the car until you collect all 4 tires. Normally there will be a double beep after complete completion, then just exit "Reset" on your DIC and you're done.