2007 Chevrolet Impala Owner's Manual - Page 411

It is possible that, if you are driving under the best conditions, the engine oil life system may not indicate that vehicle service is necessary for over a year. However, your engine oil and filter must be changed at least once a year and at this time the system must be reset. Your GM Goodwrench® dealer has GM-trained service technicians who will perform this work using genuine GM parts and reset the system. If the engine oil life system is ever reset accidentally, you must service your vehicle within 3,000 miles (5 000 km) since your last service. Remember to reset the oil life system whenever the oil is changed. See Engine Oil Life System on page 316 for information on the Engine Oil Life System and resetting the system. When the CHANGE ENGINE OIL SOON message appears, certain services, checks, and inspections are required. Required services are described in the following for "Maintenance I" and "Maintenance II." Generally, it is recommended that your first service be Maintenance I, your second service be Maintenance II, and that you alternate Maintenance I and Maintenance II thereafter. However, in some cases, Maintenance II may be required more often. Maintenance I - Use Maintenance I if the CHANGE ENGINE OIL SOON message comes on within 10 months since the vehicle was purchased or Maintenance II was performed. Maintenance II - Use Maintenance II if the previous service performed was Maintenance I. Always use Maintenance II whenever the CHANGE ENGINE OIL SOON message comes on 10 months or more since the last service or if the message has not come on at all for one year. Scheduled Maintenance Service Change engine oil and filter. See Engine Oil on page 312. Reset oil life system. See Engine Oil Life System on page 316. An Emission Control Service. Visually check for any leaks or damage. See footnote (k). Maintenance I Maintenance II 411