New bipartisan legislation could establish long-needed ADAS calibration guidance for modified vehicles.
When a collision-damaged vehicle arrives at a calibration center with a lift kit or aftermarket bumper, the technician faces a dilemma that has no good answer under current guidelines: Calibrate it without clear procedures and accept the liability, or send it back to the road with ADAS systems that may not function as designed.
A federal bill introduced in the U.S. House of Representatives on Dec. 15 aims to address that gap. The ADAS Functionality & Integrity Act (H.B. 6688), backed by the Specialty Equipment Market Association (SEMA) and introduced by Rep. Diana Harshbarger (R-Tenn.) with bipartisan co-sponsors, would direct the National Highway Traffic Safety Administration (NHTSA) to establish calibration guidelines and modification tolerances for vehicles equipped with advanced driver-assistance systems.
For collision repair shops, the legislation arrives at a moment when ADAS calibration has become a routine part of the repair process but modified vehicles remain a persistent complication.
“Right now, the industry operates in a gray zone where there’s no standardized playbook for post-modification calibration,” said Adi Bathla, founder and CEO of Revv, an ADAS calibration software provider. “Shops are making judgment calls based on outdated information, and that creates huge liability risks and inconsistent outcomes.”
The scope of the problem
Modified vehicles represent a relatively small share of calibration work. Steve Davis, founder and CEO of Techmotive, a calibration services provider, estimates they account for roughly 2%-5% of the vehicles his company sees. But the complications they create are significant.
“A lot of the OEMs specifically say that if you’ve modified the ride height or the suspension, you cannot calibrate the vehicle,” Davis said. When his team encounters a modified vehicle, they attempt to return it to proper ride height before calibrating. “Whatever the customer does after that is on them.”
That workaround isn’t always possible, and some calibration providers have chosen to decline modified vehicles entirely rather than accept the liability. The result, according to Bathla, is that “vehicles can end up back on the road without ADAS being properly addressed, not because shops don’t care about safety, but because they don’t have clear rules to follow.”
The challenge extends beyond obvious modifications, such as lift kits. License plate relocations, certain bumper stickers with metallic backings, and changes to wheel and tire sizes can all affect ADAS sensor performance. Even a bike rack can disrupt a rearview camera’s field of vision.
“Up until this moment of technology in our vehicles, any modification has been largely mechanical,” said Karen Bailey-Chapman, SEMA’s senior vice president of public and government affairs. “But now, because of these ADAS systems, that changes. Now it’s, ‘How does that modification intersect with technology?’”
What the bill would do
The legislation directs NHTSA to publish guidelines explaining how common aftermarket modifications may affect ADAS safety features, establish modification ranges and tolerances for model year 2028 and newer vehicles, and create test procedures that aftermarket businesses can use to validate calibrations.
The timeline aligns with the federal automatic emergency braking mandate under Federal Motor Vehicle Safety Standard 127, which takes effect for model year 2029 vehicles. SEMA’s goal is to have the bill included in the federal highway bill reauthorization expected in 2026.
Bailey-Chapman emphasized that the legislation represents a starting point rather than a final solution. “This is not a one-and-done,” she said. “As the technology advances and regulations try to keep up, I think this will continue to evolve.”
The bill requires NHTSA to collaborate with vehicle manufacturers, standard-setting organizations, dealers, and the aftermarket industry in developing the guidelines. SEMA said it has had “productive conversations” with OEMs on the topic, though Bailey-Chapman stopped short of characterizing the automakers’ position as alignment.
OEMs are already moving
Some automakers aren’t waiting for federal action. Davis pointed to recent changes in Toyota’s approach, talking about how the 2025 Tacoma’s radar system includes procedures and measurements specifically designed for lifted vehicles.
“They actually now allow you to [calibrate] lifted vehicles,” Davis said. “So the auto manufacturers are starting to understand this kind of on their own, and they’re trying to figure out ways to accommodate aftermarket lifts.”
General Motors has offered a factory lift kit for some truck models that includes camera reconfiguration and electronic power steering calibration to maintain ADAS functionality, though it works only with that specific kit.
Davis expects market pressure to accelerate this trend. “Now that Toyota has allowed it, anybody who wants to modify a vehicle is going to go towards Toyota,” he said. “So then Nissan and GM, they’re going to have to come up with their own solutions for it. There are enough people [who] want to modify their trucks that there is going to be a demand.”
For calibration providers, OEM-developed procedures provide the clearest path to performing the work confidently. “I would have no problem calibrating that car,” Davis said of vehicles with manufacturer-supported modification procedures. “If I have to go to court to defend my actions, I could say, ‘Toyota says I can calibrate this 3-inch lift on this Tacoma, and this is the process.’”
What federal standards would enable
For software platforms like Revv that help shops identify required calibrations and manage workflows, federal standards would provide a foundation that doesn’t currently exist.
“If this bill passes and clear procedures are developed, it would give us a regulatory foundation to build directly into our platform,” Bathla said. “When a shop modifies a vehicle, our system will automatically flag what calibrations are required, what the acceptable ranges are, and how to verify everything is functioning correctly.”
The broader benefit, according to Bathla, would be shifting the industry’s focus from liability avoidance to compliance. “Instead of shops asking, ‘Are we liable?’ they’d be asking, ‘Are we compliant?’” he said. “That’s a huge shift. When shops have clear expectations and test procedures, they can document their work with confidence.”
Currently, calibration outcomes can vary significantly depending on where a vehicle is repaired. “A customer can get their vehicle repaired at three different shops and receive three completely different approaches to ADAS calibration,” Bathla said. “That inconsistency isn’t just confusing — it puts a ton of pressure on shops trying to repair cars safely without a clear rulebook to follow.”
What shops should do now
With federal guidelines still years away at best, shops and calibration providers are left to navigate the current uncertainty.
Davis emphasized the importance of continuous education. “Because of how fast it is moving, it is really just education, education, education and staying on top of that,” he said. His company invests significant time gathering information from OEMs and, when possible, the engineers who design the calibration systems. “Gathering information to try and stay ahead is half of our job.”
Bailey-Chapman pointed to SEMA’s white papers on modification tolerance testing, which cover select truck models, as a resource for shops interested in the topic. She also encouraged information sharing within the industry. “How somebody does one thing may be different than how somebody else does,” she said. “We all learn from each other.”
For shops that want to influence the legislation’s development, Bailey-Chapman recommended engaging with members of Congress as the bill is being examined. SEMA’s grassroots advocacy site, semahq.org, provides resources for contacting lawmakers.
The bottom line for collision repair operations is that modified vehicles will continue to present calibration challenges, regardless of what happens with this legislation. But the bill’s introduction signals that the issue has reached a level of visibility that may accelerate solutions, whether they come from federal regulators, OEMs responding to market pressure, or both.
“Today’s new car is tomorrow’s old car,” Bailey-Chapman said. “These technologies will be in the used market. They already are in the used market, which is where the modifier community also exists. We have to start to address these technical questions now.”
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