L Series (2003)

What to check on a used 2003 GMC L Series

On a used 2003 GMC L Series, the systems with the most NHTSA owner complaints are the steering (30), the electrical system (29) and the brakes (25). Each one has an inspection step below, with counts as of 2026-10-12. A complaint is an owner report, not a confirmed defect, and counts rise with sales.

1. Turn the wheel from lock to lock while parked, then drive straight on a level road with a light grip.Safety. NHTSA has 30 owner complaints on the 2003 GMC L Series about the steering.
2. Switch on every electrical item in turn: lights, windows, locks, wipers, climate fan, screen and power outlets.Costly repair. NHTSA has 29 owner complaints on the 2003 GMC L Series about the electrical system.
3. On an empty road, brake firmly from 40 mph with a light grip on the wheel.Safety. NHTSA has 25 owner complaints on the 2003 GMC L Series about the brakes.
4. Start the engine cold and listen for the first 30 seconds, then again at idle once it is warm.Costly repair. NHTSA has 22 owner complaints on the 2003 GMC L Series about the engine, all engines combined.
5. With the engine cold, check the coolant level and color, then watch the temperature gauge on the drive.Costly repair. NHTSA has 22 owner complaints on the 2003 GMC L Series about the cooling system, all engines combined.