Heavy-duty diesel diagnostics in Huntsville, AL

Warning light, lost power, or a fault that keeps returning?

Limestone provides scheduled mobile diesel diagnostics for semi-trucks, medium-duty work trucks, and diesel pickups. Tell us what changed and how the vehicle behaves. A fault code is helpful if you have it, but you do not need one to request service.

• Check-engine lights and recurring fault codes
• Reduced-power or derate complaints
• Intermittent electrical faults
• No-start and hard-start concerns

Troubleshooting starts with the complaint.

We review the symptoms and equipment, inspect and test the relevant systems, and explain the findings before discussing proposed repairs. Starting and charging faults and aftertreatment warnings have dedicated service pages below if either describes your concern.

Cummins and Detroit diesel support.

We service Cummins- and Detroit-powered equipment. Include the engine model if known, along with the truck details and symptoms, so we can review the diagnostic and repair needs for your specific application.

ECM programming & updates.

Engine control module programming and software updates are available by appointment. Share the truck and engine details, along with the programming or update needed, so we can confirm the application and scope before scheduling.

What should I include with a diagnostic request?

Include the year, make, model, engine if known, and whether the issue happens at startup, while driving, under load, or intermittently. Share any dashboard message, available fault codes, and recent repairs. Photos can be attached privately to your request.

Does a fault code identify the part to replace?

A code is a starting point for investigation. The symptoms and test findings determine the next step; a code or an online request alone does not establish a diagnosis. We discuss the proposed work with you before proceeding.