hold the odometer button while putting the key in and turn it to accessory while still holding the button in. your gauges should sweep back and forth. you then can push the button giving you different parameters of the car at current time. You can get rpm, current speed and such. Just warm your car up to operating temp.. shouldn't take too long and put needle in the middle where it normally sits. the rmps you can do while the car is idling. you can do the speed while on a back road or parking lot.