THE SCR STORY — BENEFITS FROM SELECTIVE CATALYTIC REDUCTION SYSTEM MAINTENANCE

THE ROLE OF SCR MAINTENANCE IN SUSTAINING FUEL EFFICIENCY AND ENGINE OUTPUT POWER

Does a poor functioning SCR (Selective Catalytic Reduction) system in your diesel pickup affect engine power output and fuel efficiency? Yes, it does. A poor functioning SCR can negatively affect engine power output and fuel efficiency. The SCR technology is designed to, chiefly, reduce NOx (nitrogen oxides) emissions, but in tandem with that chore is its design to provide optimal fuel efficiency and engine power output if and when the SCR is efficient at removing the nitrogen oxides from the exhaust emissions. When the SCR system is not functioning well in reducing NOx from the exhaust, the higher than normal particles in the exhaust can lead to a reduced overall efficiency in both fuel efficiency and engine power output.

To the point of reduced engine power output, a malfunctioning SCR system may not be able to maintain the exhaust aftertreatment system’s specified level of NOx reduction and this can result in the engine working harder to meet emissions standards, thereby potentially leading to a decrease in power output.

Regarding fuel efficiency, a poorly functioning SCR system may not be able to provide the optimal level of fuel efficiency because the engine, the aftertreatment system, the control module, sensors and other devices, rely in part, on a properly functioning SCR whose technology calibrates the engine more efficiently which can translate to better fuel economy. If the SCR system is not working correctly, the engine calibration will likely be off, out of specification; so, the engine is likely to not operate at the designed efficiency calibration, thus potentially negatively effecting fuel efficiency with a reduction in miles per gallon.

A poor functioning diesel SCR system can negatively impact, both, engine power output and fuel efficiency. To maintain the proper function of the SCR system it is essential to adopt a strict adherence to the manufacturer scheduled maintenance and replacement timelines. Cummins Automotive & Diesel Service encourages you to schedule their experienced technicians for periodic SCR system service and maintenance, in accordance with the manufacturer recommended timelines in your diesel truck’s owner’s manual. As is the case with maintaining a proper functioning SCR system, it is equally as important to repair a deficient SCR system to ensure optimal engine performance and fuel economy.

GM Releases Fix For 2024 Chevy Silverado HD Duramax Selective Catalyst Reduction Fault

The following was a newly released notification, on April 15, 2024, by Jonathan Lopez at GM Authority.

General Motors has released a service update for units of the 2024 Chevy Silverado HD equipped with the 6.6L V8 L5P turbodiesel Duramax diesel engine. The update targets a specific issue with the Selective Catalyst Reduction (SCR) system, considered an essential component of the vehicle’s emission control technology. The service update will be applied to vehicles in dealer inventory and customer vehicles that return to the dealership.
The new service update is tagged as N242438501, and was released in April of the 2024 calendar year. The service update only applies to the 2024 model year for the Chevy Silverado 2500 HD and 3500 HD, and only those units equipped with the 6.6L V8 L5P turbodiesel Duramax diesel engine. It’s unclear exactly how many units are affected by this particular Service Update.
The problem lies within the Engine Control Module (ECM) software, which may fail to correctly diagnose or may not set Diagnostic Trouble Codes (DTCs) for the Selective Catalyst Reduction (SCR or NOx) catalyst system. This failure could prevent the Malfunction Indicator Light (also known as the Check Engine Light) from alerting drivers to SCR-related issues.
To fix the issue, GM has directed dealerships to reprogram both the ECM and the Transmission Control Module (TCM). No replacement parts are required for this fix, suggesting that the issue can be resolved entirely through software.
Jonathan Lopez, at GM Authority

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