GM Service Manual Online
For 1990-2009 cars only

The speedometer shows the vehicle speed in both miles per hour (mph) and kilometers per hour (km/h). The odometer shows how far the vehicle has been driven.

If the vehicle needs a new odometer installed, the new one must be set to the mileage total of the old odometer. If it cannot be reset, then it must be set at zero and a label put on the driver door to show the old mileage reading when the new odometer was installed. See your dealer/retailer for more information.