At I-55 Truck and Trailer Repair, we’re actively helping drivers and fleets navigate the latest EPA guidance that has tightened DEF and emissions fault responses. The engine and aftertreatment software must maintain complete updated status together with DEF quality verification and minor fault code resolution to prevent sudden derates. From our OEM-level diagnostics, we verify calibration status while implementing software updates and fixing sensor and dosing issues to prevent unexpected 5-mph shutdowns that can leave trucks stranded on their routes.

As alternative-fuel trucks become more common, we’ve invested in technician training and shop safety procedures specific to high-voltage and hybrid systems. Our team has all the necessary tools to safely diagnose and service electric and hydrogen-hybrid components according to manufacturer regulations which include proper lockout procedures and insulated tooling and system diagnostics. We’re ready to assist fleets with new technology implementation while maintaining safety standards and vehicle requirements.

Abnormally frequent regenerations are a warning sign we take seriously. Our diagnostic process includes exhaust backpressure analysis and fluid contamination checks to confirm whether the DPF experiences normal loading or gets poisoned by internal engine coolant and oil leaks. The data we present will enable us to explain the situation to you and it offers a complete understanding of our problem.

The parts availability situation in 2026 results in significant differences between different regions, which leads us to provide accurate time estimates before we take your truck to the service area. We evaluate both OEM and remanufactured products through regional distributors to determine which items we can acquire more quickly while maintaining our quality standards. We will suggest the most effective reman unit to use as a local solution because this option will reduce downtime; however, we will provide full details about the unavoidable delays which fleet managers need to plan for their operations.

We evaluate repairs through the lens of real DOT inspection criteria, not guesswork. Our technicians can explain whether an issue-such as a minor air leak, lighting fault, or emissions warning-is likely to trigger a roadside violation or negatively impact your CSA score. Safety managers and drivers use this information to choose between short-haul operations and immediate repairs, which enables them to meet safety requirements while maintaining their operational performance.