Cummins will pay California $175M over emission-rigged engines

Fines and mitigation penalties bring total outlay to nearly $2 billion

Cummins Inc. agreed to pay $175 million to California in an emissions-cheating case, (Photo: Cummins Inc.)

Cummins Inc. will pay $175 million to California over emissions-rigging of Ram truck diesel engines. Along with $33 million for environmental violations and unfair business practices, it brings federal and state penalties to nearly $2 billion.

The Columbus, Indiana-based engine maker and advanced technology provider agreed Dec. 22 to a federal fine of $1.675 billion involving diesel engines in Ram trucks built over a decade. California’s share of the federal fine was $164 million. All told, the state will get about $372 million.

The federal civil penalty was the largest in the history of the Clean Air Act and second-largest fine overall. It followed the $2.6 billion criminal penalty that Volkswagen AG paid for emissions cheating in 2015. That arose from what became known as the “Dieselgate” scandal.

In a 158-page consent decree filed Wednesday in the U.S. District Court for the District of Columbia, Cummins agreed to make software changes at no cost to truck owners.

Emission-defeating software on 97,000 engines in California

The case involves approximately 97,000 engines in California and hundreds of thousands of vehicles nationwide. The California Air Resources Board discovered the defeat device violations in model years 2013 to 2018 Ram 2500 and 3500 trucks with the 6.7-liter diesel engine.

CARB used advanced testing methods and protocols developed to detect software programs that alter or shut down a vehicle’s emissions control system under normal driving operation.The U.S. Environmental Protection Agency partnered with CARB on the investigation, which revealed additional violations in 2019 to 2023 model year Ram 2500 and 3500 trucks.

’Knowingly harmed people’s health’

“Cummins knowingly harmed people’s health and our environment when they skirted state emissions tests and requirements,” California Attorney General Rob Bonta said in a news release. “Today’s settlement sends a clear message: If you break the law, we will hold you accountable.”

Cummins typically is responsible for certifying emissions only on its engines. In the case of the Ram trucks, Cummins certified that both the engine and the overall vehicle complied with federal regulations.

The company admitted no wrongdoing. It said in a statement that it is “looking forward to obtaining certainty as we conclude this lengthy matter.” Cummins reserved just over $2 billion against its fourth-quarter earnings for the federal and state penalties.

Auxiliary emission control devices rarely allowed

Software known as auxiliary emission control devices are allowed only when engine makers tell authorities of their existence in advance of certification. They typically are allowed only to protect the engine.

In this case, Cummins did not disclose the existence of the auxiliary emission control devices. The software changed the engine’s performance to meet rigorous emission standards during certification testing in the lab. But the emission control equipment shut down during real-world driving.

The Cummins engines involved in the case emitted smog-forming oxides of nitrogen (NOx) that were above the legal limit. NOx pollution contributes to the formation of ozone and particulate matter, which can aggravate health problems such as asthma and cardiopulmonary disease. 

Cummins will pay $1.675B fine for engine emissions violations

EPA has questions for Cummins over Ram engines

Click for more FreightWaves articles by Alan Adler.

Upcoming FreightWaves Events
Compliance

Brokerage Compliance Symposium

The day before F3. Every compliance issue you face - fraud exposure, carrier liability, FMCSA rules, cargo theft, insurance gaps - navigated by attorneys and operators defining best practices in a changing industry.

October 26, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
Awards

F3 Awards Dinner

The night before F3. FreightTech100 companies honored. FreightTech 25 and Shipper of Choice winners revealed live. Cocktail reception into dinner and live music - 300 industry leaders in one purpose-built room.

October 26, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
FreightTech

F3: Future of Freight Festival

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

October 27, 2026 – October 28, 2026
The Signal at Chattanooga Choo Choo • Chattanooga, TN
Register Now
Compliance Brokerage Compliance Symposium Oct 26 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

The day before F3. Every compliance issue you face - fraud exposure, carrier liability, FMCSA rules, cargo theft, insurance gaps - navigated by attorneys and operators defining best practices in a changing industry.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now
Awards F3 Awards Dinner Oct 26 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

The night before F3. FreightTech100 companies honored. FreightTech 25 and Shipper of Choice winners revealed live. Cocktail reception into dinner and live music - 300 industry leaders in one purpose-built room.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now
FreightTech F3: Future of Freight Festival Oct 27 – Oct 28 • The Signal at Chattanooga Choo Choo • Chattanooga, TN

Industry-defining keynotes, rapid-fire technology demos, and industry leaders networking in experiences across Chattanooga - plus the inaugural F3 Awards Dinner featuring the FreightTech and Shipper of Choice reveals.

The Signal at Chattanooga Choo Choo • Chattanooga, TN Register Now

Alan Adler

Alan Adler is an award-winning journalist who worked for The Associated Press and the Detroit Free Press. He also spent two decades in domestic and international media relations and executive communications with General Motors.