The U.S. Environmental Protection Agency on Wednesday issued new guidance requiring vehicle and equipment manufacturers to provide independent repair shops and consumers with the same diagnostic and repair information available to branded service centers.
The move, which covers light-, medium-, and heavy-duty vehicles, specifically addresses access to tools and data needed to fix Diesel Exhaust Fluid (DEF) and other emissions control systems.
Under EPA’s regulations, manufacturers must provide:
- Full emissions-related service information
- Training materials
- OBD data and enhanced diagnostics
- Passthrough reprogramming information
- Manufacturer-specific tools for purchase
The action follows a presidential memorandum issued two days ago by President Donald Trump titled “Lowering the Cost of Living by Promoting the Freedom to Fix.” It builds on a February 2026 EPA measure that extended similar right-to-repair provisions granted to farmers and other users of nonroad diesel equipment.
Independent mechanics and vehicle owners have long faced hurdles repairing modern emissions systems. Manufacturers have often cited the Clean Air Act’s anti-tampering laws as a reason to withhold certain digital tools and software, arguing that sharing them could facilitate the illegal bypassing of emissions controls leaving—operators no choice but to tow or limp vehicles to OEM-branded dealerships.
The EPA's new guidance clarifies that the Clean Air Act allows temporary overrides of emissions systems if done strictly for the "purpose of repair." Under the law, EPA charges, manufacturers have an obligation to release necessary service data, training materials, and tools on reasonable terms, the agency said.
Additionally, the EPA reinforced consumer protection rules under the Clean Air Act, stating that manufacturers cannot mandate the use of branded parts, allowing for equivalent generic parts be permitted for emissions repairs. However, the agency clarified that using uncertified parts does not guarantee warranty coverage.
The EPA emphasized that the guidance does not alter existing laws, weaken federal emissions standards, or require manufacturers to disclose proprietary software codes, trade secrets, or intellectual property.
