Who Should Fix Ag Equipment Emissions?

National Crackdown on Diesel Emissions Tampering Brings Focus on Right to Repair

Todd Neeley
By  Todd Neeley , DTN Environmental Editor
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Roger Hoy, director of the tractor test laboratory at the University of Nebraska-Lincoln, said there are several important points to consider when talking about the right to repair and emissions controls on tractors and other ag implements. (DTN photo by Todd Neeley)

LINCOLN, Neb. (DTN) -- Maintaining emissions-control systems on tractors and other ag equipment is at the heart of the right-to-repair national dispute between agriculture equipment manufacturers and some farmers and independent repair shops.

Farmers and those shops want to have available diagnostics and other equipment to be able to make emissions repairs, while manufacturers are concerned about potential tampering and want that kind of repair work done by trained dealers.

At the end of April, three trucking companies and 11 people were charged with violating the Clean Air Act in an aftermarket scheme to disable emissions-control systems on semi-trucks.

It was part of an ongoing effort by EPA and other federal agencies since 2020 to put an end to the practice the agency says is leading to increased pollution emissions, https://www.justice.gov/….

So, how does this federal effort affect the right-to-repair movement, and do stories of emissions tampering make the case for equipment manufacturers that repairs should be done by trained dealers?

The answers to those questions aren't always clear-cut, according to equipment industry experts.

"So, I think this is something that we hear a lot of from manufacturers is that they support the right to repair, but they don't support the right to modify, and I'll say we don't support the right to modify either," said Kevin O'Reilly, director of the Public Interest Research Group's, or PIRG, right-to-repair campaign.

"That is an entirely separate process. Whether it's chipping or other procedures that are taken to skirt the emission standards, those have nothing to do with the tools that we're asking for the right to repair. So, while I do think that manufacturers try to conflate the two issues, the fact of the matter is that nothing in right to repair will make that easier."

O'Reilly told DTN during a recent Iowa Farmers Union Zoom call that some people may be tampering with emissions equipment because they don't have access to the right tools to make repairs.

The state of Colorado recently passed a law that gives farmers and repair shops access to the right tools. O'Reilly said the legislation, however, did not legalize tampering for the sake of bypassing emissions controls.

"I think that they're two completely separate issues," he said.


Earlier this year, the American Farm Bureau Federation signed separate memorandums of understanding with John Deere and CNH Industrial Brands, to expand access to diagnostics and other tools for farmers and independent repair shops wishing to make repairs.

John Deere's MOU grants the ability to pay for subscriptions or access to Deere diagnostic tools and product guides needed to make repairs.

The CNH MOU ensures farmers as well as any staff or independent technician or repair shop will have electronic access "on fair and reasonable terms" to Case IH and New Holland tools, specialty tools, software and documentation, including manuals, to make needed repairs. That access will be granted "per subscription or sale."

Right-to-repair groups such as PIRG question whether the agreements will provide any meaningful access to farmers and repair shops.

Roger Hoy, director of the tractor test laboratory at the University of Nebraska-Lincoln, told DTN during an interview that there are several important points to consider when talking about the right to repair and emissions controls on tractors and other ag implements.

Even trained equipment dealers are not authorized to modify or defeat emissions systems, Hoy said, and repairs on those systems must meet specifications.

"The EPA today doesn't regulate the end user -- they regulate the manufacturer," Hoy said.

"The manufacturer is responsible for making sure that machines they produce comply with EPA. If there's third parties or others out there that are defeating the emissions controls, that puts the manufacturer in a bad position with the EPA. I frankly think that any farmer or even third-party repair shop should have access to the same tools and training at the same costs an authorized dealer has."


According to the EPA, violation of the tampering-and-defeat- device prohibitions in the Clean Air Act may result in civil penalties of more than $4,800 per defeat device manufactured, sold, or installed, or per vehicle tampered -- that includes tractors and other farm machines.

A dealer or vehicle manufacturer who tampers with a vehicle may be subject to significantly higher civil penalties.

Tractors, in particular, use a couple of different emissions systems.

One is a diesel exhaust fluid, or DEF, system that requires farmers to keep DEF tanks full when running their tractors. The DEF fluid is used to reduce diesel emissions.

Another after-treatment system common on tractors is the DPF regeneration system. Hoy said DPF uses a particulate filter that collects particulate matter. The filter regenerates itself by injecting diesel and igniting it in the exhaust system. This raises temperatures high enough to vaporize the particulates.

Hoy, who worked as an engineer for John Deere before coming to UNL, testified in a neutral capacity on a right-to-repair bill that was before the Nebraska Legislature in 2022.

Hoy said because manufacturers have seen the benefits of using computer technology to operate emissions and other technologies on tractors, farm implements are becoming increasingly more complex.

"The old mechanical gearhead kind of person is probably going to be really intimidated by a lot of that," he said.

The ag equipment industry has made tractors and other machines safer, he said.

John Deer machines, for example, have power shifters that require at least two motions to shift to prevent accidents.

"There's some stuff that I think ought to be held by the manufacturer that nobody -- not authorized dealers, not farmers, not third-party shops -- can mess with, and it's not just emissions," Hoy said.

"You can't take a tractor out of park and put it into gear without making a conscious motion to do that. So, just bumping the handle would not get it out of park accidentally."

The machines have sensors that detect the shift handle being moved into the proper orientation, he said.

Because safety features and emissions are so important, Hoy said repairs to those systems should be handled by manufacturers.

"And so, if their source code is completely opened up, people that aren't even aware of what's happening and why it's happening could possibly make that (machine) unsafe," Hoy said.

"That's why I think that things like control of things that do affect the emissions of the tractor, that affect the safety functions of the tractor ought to just be left with the manufacturer. That doesn't preclude someone from repairing a tractor that needs to be repaired with the same skills and tools available that an authorized dealer would have."

Read more about EPA's enforcement efforts on diesel emissions tampering here: https://www.epa.gov/….

Read more on DTN:

"A New Farmer Right-to-Repair MOU," https://www.dtnpf.com/…

"AFBF Strikes Deal on Right to Repair," https://www.dtnpf.com/…

Todd Neeley can be reached at todd.neeley@dtn.com

Follow him on Twitter @DTNeeley

Todd Neeley

Todd Neeley
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