Diesel DPF & SCR Aftertreatment Diagnostics

Mechanic performing heavy-duty diesel engine repair on truck with cab tilted up in San Antonio TX
Accessing the engine for complex diesel diagnostics and heavy-duty repair. We specialize in minimizing downtime for San Antonio truck owners.

Specialized diagnostics for Cummins, Power Stroke, and Duramax Aftertreatment systems.

Diesel DPF & SCR Aftertreatment Diagnostics in San Antonio | Solve Limp Mode

Automotive Brake & Clutch is your San Antonio specialist for Diesel Aftertreatment System (ATS) troubleshooting. We provide expert diagnostics for DPF (Diesel Particulate Filter) and SCR (Selective Catalytic Reduction) systems. Our team specializes in identifying sensor failures, managing forced regenerations, and professional filter removal and re-installation for deep cleaning services.

Using Cummins Insite and J-Pro diagnostics, we pinpoint the exact cause of “Limp Mode” and DEF quality warnings. We take the complexity out of emissions repair by handling the technical removal and computerized resets required to get your heavy-duty truck back into service.

Comprehensive Aftertreatment & Emissions Service

How Your Diesel Aftertreatment System Works

Modern diesel engines rely on a multi-stage process to neutralize soot and NOx gases. When the DPF becomes restricted or the SCR catalyst fails to reach temp, your engine will “derate” to protect the system. We perform specialized aftertreatment diagnostic estimates to determine if the issue is a failed sensor, a clogged injector, or if the filter requires professional off-site cleaning.

Diesel aftertreatment system diagram showing DPF and SCR flow for commercial truck repair

ATS Architecture: Critical components for Federal Emissions Compliance.

ATS Diagnostics

Computerized troubleshooting of NOx sensors, temperature probes, and DEF dosing pumps to clear active fault codes.

DPF Removal Service

When filters are “ash-locked,” we perform professional removal and coordinate off-site cleaning to restore flow to OEM specs.

Forced Regens

Using OEM-level software, we trigger parked regenerations to clear soot and verify system health after repairs.

Diesel Emissions FAQ

What is the difference between DPF and SCR?
The DPF (Diesel Particulate Filter) captures physical soot (black smoke), while the SCR (Selective Catalytic Reduction) uses DEF fluid to break down nitrogen oxides (NOx) into nitrogen and water. We provide full diagnostics for both critical stages.
Are diesel vehicles exempt from Bexar County emissions testing in 2026?
Yes. Diesel engines are currently exempt from the local emissions testing program starting in 2026. However, federal law still requires all factory emissions equipment (ATS) to be present and functional for road safety and compliance.
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Verified History: We Report to CARFAX®

We report all emissions maintenance to CARFAX, providing a verified service history that protects your engine’s resale value.

Maximize Your Diesel Uptime

Don’t let a “Full DPF” message sideline your business. Contact Automotive Brake & Clutch for a specialized aftertreatment diagnostic estimate today.