2003 GMC Sonoma Owner's Manual - Page 391

If you do not use your vehicle under any of these conditions, change the fluid and filter every 50,000 miles (83000 km). 0 Replace fuel filter. An Emission Control Service. (See footnote t.) 0 Replace engine air cleaner filter. An Emission Control Service. 0 Rotate tires. See Tire Inspection and Rotation on page 5-66 forproper rotation pattern and additional information. (See footnote +.) 100,000 Miles (166 000 km) 0 Inspect spark plug wires. An Emission Control 97,500 Miles (162 500 km) 0 Change engine oil and filter (or every 12 months, Service. 0 Replace spark plugs. An Emission Control Service. 0 If you haven't used your vehicle under severe service conditions listed previously and, therefore, haven't changed your automatic transmission fluid, change both the fluid and filter. Manual transmission fluid doesn't require change. 0 4.3L V6 Engine Only: Inspect Positive Crankcase Ventilation (PCV) valve. An Emission Control Service. 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 +.) 150,000 Miles (240 000 km) 0 Drain, flush and refill cooling system (or every 60 months since last service, whichever occurs first). See Engine Coolant on page 5-27for what to use. Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test the cooling system and pressure cap. An Emission Control Service. 0 Inspect engine accessory drive belt. An Emission Control Service. 6-24