reports Sen. Dan Sullivan outlining a proposed 'Diesel Reliability Act' to prevent DEF-freeze engine shutdowns in cold climates.
Sponsor and push the "Diesel Reliability Act" to prevent diesel exhaust fluid (DEF) from freezing and causing engine shutdowns in cold climates.
Occurrences
supports S.3135 to ensure equipment reliability in Arctic conditions
Senator Dan Sullivan welcomed an EPW Committee hearing to examine S.3135, the Cold Weather Diesel Reliability Act.
S.3135 - 119th Congress (2025-2026): Cold Weather Diesel Reliability Act of 2025
Senator Dan Sullivan's official press release (Nov. 13, 2025) announces introduction of the Cold Weather Diesel Reliability Act (co-sponsored with Sen. Cynthia Lummis), describes DEF-freezing-triggered engine shutdowns as a safety/reliability problem in cold states, and quotes Sullivan urging regulatory changes and legislative action to prevent those shutdowns.
Evidence
S.3135, the 'Cold Weather Diesel Reliability Act of 2025,' lists Senator Dan Sullivan (R–AK) as a sponsor and was introduced on November 6, 2025; the bill would direct EPA to allow manufacturers to suspend engine derate or shutdown functions in prolonged cold-weather conditions (i.e., where diesel exhaust fluid can freeze).
April 15, 2026 article reports Senator Dan Sullivan publicly promoting a proposed 'Diesel Reliability Act' (Cold Weather Diesel Reliability Act / S.3135), saying current emissions rules can leave drivers stranded when diesel exhaust fluid (DEF) freezes and outlining the proposed regulatory fixes.
Official bill text (S.3135) lists Senator Dan Sullivan as a sponsor of the Cold Weather Diesel Reliability Act of 2025 and describes statutory changes directing EPA regulatory flexibility to address DEF-related cold-weather engine derates/shutdowns.
News coverage (Apr 15, 2026) documents Sen. Sullivan publicly promoting and pushing the proposed Diesel Reliability legislation and regulatory fixes to prevent DEF-related shutdowns, citing interviews and his advocacy for the bill.
Congress.gov bill text for S.3135 (Cold Weather Diesel Reliability Act of 2025), introduced Nov. 6, 2025, lists Senator Dan Sullivan (R–AK) as an introducer/sponsor. The bill text directs EPA to authorize a temporary cold-weather operational mode to suspend engine derate/shutdown functions triggered by diesel exhaust fluid (DEF) system faults and to grant year‑round exemptions for vehicles operating primarily in prolonged freezing conditions.
Senator Dan Sullivan's official press release (Nov. 13, 2025) announces introduction of the Cold Weather Diesel Reliability Act (co-sponsored with Sen. Cynthia Lummis), describes DEF-freezing–triggered engine shutdowns as a safety/reliability problem in cold states, and quotes Sullivan urging regulatory changes and legislative action to prevent those shutdowns.
Official bill text for S.3135 (Cold Weather Diesel Reliability Act of 2025) shows Senator Dan Sullivan (R-AK) as an introducer/sponsor and directs the EPA to authorize manufacturers to suspend inducement-related engine derates or shutdowns triggered by emissions-control faults when ambient temperatures are at or below 0°C, with other procedural conditions.
EPA issued guidance in March 2026 urging engine and equipment manufacturers to revise DEF-system software and announcing removal/relaxation of certain DEF sensor requirements, enabling manufacturer fixes and temporary regulatory flexibility to avoid sudden engine derates/shutdowns in cold conditions.
Official bill text (S.3135) lists Sen. Dan Sullivan (R‑AK) as an introducer/sponsor and directs the EPA to grant exemptions from engine derate/shutdown requirements triggered by diesel exhaust fluid (DEF) system faults in cold conditions, explicitly targeting DEF-induced derates/shutdowns.
EPA press release and March 2026 fact sheet implement guidance and further administrative steps (data requests, updated sensor/derate guidance) intended to prevent abrupt DEF-related engine derates/shutdowns in existing and new vehicles—operational regulatory action aligned with the bill's objective.
Official Senate bill text for S.3135 (Cold Weather Diesel Reliability Act of 2025) lists Sen. Dan Sullivan as a sponsor and directs the Environmental Protection Agency to provide regulatory authority/flexibility to address DEF-related engine derates and shutdowns in cold-weather conditions.
U.S. EPA press release (March 27, 2026) announcing guidance and measures directing engine and equipment manufacturers to revise DEF-system software, clarifying alternative monitoring/operational approaches, and adjusting enforcement expectations to reduce DEF-triggered derates/shutdowns.
Congress.gov bill record and official bill text for S.3135 (introduced Nov 6, 2025) list Senator Dan Sullivan as an introducer/sponsor of the Cold Weather Diesel Reliability Act of 2025. The statute text instructs the EPA to provide regulatory relief and technical adjustments (including temporary suspension/exemptions of emissions-related derates/shutdowns tied to DEF failures) for vehicles/equipment operating primarily in cold-weather conditions, directly matching the core policy language of the campaign claim.
The U.S. EPA issued a March 27, 2026 news release and accompanying technical fact sheet implementing new guidance on Diesel Exhaust Fluid (DEF) systems that (1) removes or relaxes certain DEF sensor requirements, (2) allows alternative monitoring/technical approaches, and (3) adjusts enforcement expectations to reduce DEF-triggered engine derates and shutdowns. The release frames these administrative actions as addressing the exact operational failures targeted by S.3135 and provides the concrete regulatory/admin measures that realize the bill's objective. A search for additional developments during the lookback window (Apr 21–23, 2026) found no new official actions that change this assessment.
The Congress.gov bill record for S.3135 lists Sen. Dan Sullivan as the sponsor and shows the bill was introduced on 11/06/2025. The bill title is the Cold Weather Diesel Reliability Act of 2025.
The bill text states: 'To require the Administrator of the Environmental Protection Agency to authorize manufacturers of certain vehicles to suspend engine derate or shutdown functions in prolonged cold weather conditions, and for other purposes.' It also says Mr. Sullivan introduced the bill with Ms. Lummis.
Sen. Sullivan's office said he and Sen. Lummis introduced the Cold Weather Diesel Reliability Act to address EPA emissions system malfunctions that can force diesel engines to shut down in extreme cold, and that the bill would prevent automatic shutdowns caused by cold-related emissions faults and provide year-round exemptions in cold-weather climates.
EPA announced on March 27, 2026 that it was removing the DEF sensor requirement for all diesel equipment and taking additional action to address DEF system failures, including sudden speed losses and shutdowns caused by DEF system failures.
The bill was referred to the Senate Committee on Environment and Public Works on 11/06/2025 and no later committee advancement appears on the official Congress.gov committee page.
Assessments
Sullivan sponsored S.3135, the Cold Weather Diesel Reliability Act of 2025, and publicly pushed its cold-weather DEF shutdown fix while serving in the same federal Senate term. Although the bill itself appears to have remained in committee, EPA took March 27, 2026 administrative action aligned with the promised objective by addressing DEF-system failures, sensor requirements, and derate/shutdown problems. Because Sullivan directly introduced and advocated the legislation and the federal policy outcome was substantially achieved during his current term, this counts as delivered rather than merely attempted.
Dan Sullivan sponsored S.3135, the Cold Weather Diesel Reliability Act of 2025, and publicly promoted it to address DEF freezing and shutdowns in cold climates. The evidence also shows he actively pushed the policy and that EPA issued related guidance and regulatory flexibility measures in 2026 that aligned with the bill’s objective, so the claim is fulfilled.
Multiple pieces of primary and secondary evidence confirm Senator Dan Sullivan sponsored and actively pushed the Cold Weather Diesel Reliability Act (S.3135) as promised. The bill's text specifically matched the campaign pledge, focusing on regulatory relief to prevent DEF-related engine shutdowns in cold climates. Subsequent EPA actions in March 2026 implemented regulatory and technical solutions aligned with the bill’s objectives, realizing the promise's intended outcome through both legislative and administrative means within the same Senate term.
Sen. Dan Sullivan sponsored and publicly pushed S.3135 (Cold Weather Diesel Reliability Act) in Nov 2025 and subsequent press/media coverage documents his advocacy. The EPA issued March 27, 2026 guidance and technical measures that implement regulatory flexibility and manufacturer directives to prevent DEF-triggered engine derates/shutdowns, achieving the bill's core objective.
Sen. Sullivan sponsored S.3135 (Cold Weather Diesel Reliability Act of 2025) and publicly advocated for it (Senate press release Nov 13, 2025; media coverage Apr 15, 2026). The bill directs the EPA to allow regulatory flexibility to prevent DEF-triggered engine derates/shutdowns, and the EPA issued guidance on Mar 27, 2026 implementing technical and enforcement measures consistent with the bill's objective. Primary legislative records (congress.gov), Sullivan's office release, and EPA press releases collectively show the sponsorship, advocacy, and administrative action that achieved the promised outcome.
Sen. Dan Sullivan introduced and sponsored S.3135 (Cold Weather Diesel Reliability Act of 2025) and publicly promoted the bill and related regulatory fixes (press release Nov 13, 2025; media coverage Apr 15, 2026). The bill text explicitly directs EPA to allow exemptions or a cold-weather operational mode to prevent DEF-triggered derates/shutdowns, and the EPA issued March 2026 guidance and follow-up measures implementing regulatory flexibility and technical fixes consistent with the bill's objective. These legislative and administrative actions fulfill the promise within the same term.
Sen. Sullivan introduced and sponsored S.3135 (Cold Weather Diesel Reliability Act of 2025) (Congress.gov bill text, Nov 6, 2025) and issued a press release announcing the bill. Media coverage documents he actively promoted and pushed the legislation, and the EPA issued March 2026 guidance implementing regulatory flexibility and technical fixes consistent with the bill’s goal to prevent DEF-related cold-weather derates/shutdowns. These actions satisfy the promise to sponsor and push the Diesel Reliability Act and produce the intended regulatory outcome within the same term.
Congressional record (S.3135, introduced Nov 6, 2025) lists Sen. Dan Sullivan as a sponsor of the Cold Weather Diesel Reliability Act directing EPA regulatory flexibility to prevent DEF-related derates/shutdowns; an official Sullivan press release (Nov 13, 2025) and subsequent news coverage (Apr 15, 2026) document him publicly promoting and pushing the bill and regulatory fixes. These sources show he both sponsored and actively pushed the proposed legislation, meeting the claim.
Congressional record (S.3135, introduced Nov 6, 2025) lists Sen. Dan Sullivan as a sponsor of the Cold Weather Diesel Reliability Act of 2025, which directs regulatory flexibility to address DEF freezing and associated engine derates/shutdowns. Subsequent news coverage (Apr 15, 2026) documents Sullivan publicly promoting and pushing the bill and related regulatory fixes. These sources show he both sponsored and actively advocated for the legislation, matching the promise to sponsor and push the Diesel Reliability Act to prevent DEF-related shutdowns.
Official congressional record (S.3135, Cold Weather Diesel Reliability Act of 2025) lists Sen. Dan Sullivan as a sponsor (introduced 11/06/2025), and subsequent media coverage (Apr 15, 2026) documents him publicly promoting and pushing the proposed bill and its regulatory fixes to prevent DEF-related shutdowns. These actions match the pledge to sponsor and push the legislation.