2003 GMC Sonoma Owner's Manual - Page 387

0 Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. If you do not use your vehicle under any of these conditions, change the fluid and filter every 50,000 miles (83 000 km). 0 Rotate tires. See Tire Inspection and Rotation on page 5-66 for proper rotation pattern and additional information. (See footnote +.) 0 4.3L V6 Engine Only: Replace fuel filter. An Emission Control Service. (See footnote t.) d Replace engine air cleaner filter. An Emission Control Service. 37,500Miles (62 500 km) 0 Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 12 months, whichever occurs first). (See footnote #,) 0 Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 0 Rotate tires. See Tire Inspection and Rotation on page 5-66 for proper rotation pattern and additional information. (See footnote +.) 45,000Miles (75 000 km) 0 Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 12 months. whichever occurs first). (See footnote #.) 0 Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 6-20