All articles tagged with #limp mode
The EPA proposes removing derates and limp-mode triggers tied to DEF failures for newly built diesel engines, aiming to cut costs and boost productivity while preserving about 90% of NOx reductions. If finalized, the rule would apply to 2027-model-year vehicles with a 45-day public comment period, and older trucks would still derate; the plan also eases warranty requirements and relies on warnings rather than immediate shutdowns.
The EPA is considering eliminating limp-mode/derate restrictions triggered by low Diesel Exhaust Fluid in diesel trucks and is requesting data from the top manufacturers to assess warranty claims, failure rates, and repairs for certain model years, with a 30-day deadline. This follows a broader shift toward deregulation under Administrator Lee Zeldin, who previously extended the window before derates took full effect. If derates may no longer be required for compliance, diesel pickups could run at higher performance without frequent DEF refills.
The EPA plans to eliminate 'low DEF' limp mode in trucks starting with 2027 models, arguing that the annoyance of the feature is unnecessary, despite it helping reduce harmful emissions. This move conflicts with existing tamper prevention regulations, raising concerns about drivers bypassing emission controls. While the regulation aims to improve air quality, critics worry it may lead to increased pollution if drivers disable DEF systems.