Cummins explains its heater control unit, a 10 kW device for cutting diesel NOx
Cummins has developed a heater control unit that delivers up to 10 kW to warm aftertreatment catalysts quickly, helping diesel engines meet ultra-low NOx standards.
- up to 10 kW
- 22,000 hours
- 2.5 million miles
- 49
What Happened
New NOx requirements are increasing the need for aftertreatment systems to reach effective operating temperatures quickly, particularly during cold starts and low-load operation. To meet ultra-low NOx standards set by state and federal regulators, Cummins developed a control technology called the heater control unit, or HCU. The HCU works alongside Cummins aftertreatment systems, which already filter particulate matter and reduce NOx emissions.
up to 10 kWkW
The HCU acts as a high-power DC/DC converter, delivering this output during startup to heat the catalyst rapidly, then intelligently adjusting it to maintain ideal conditions for NOx reduction throughout operation.
- Aftertreatment systems relied on engine heat to warm the catalyst that captures NOx
- They require additional components that operate independently of engine power to meet stricter performance demands
- Durability testing completed equivalent to 22,000 hours, corresponding to 450,000 miles
- Field validation totaling 2.5 million miles across 49 vehicles
Cummins has advanced emissions reduction technology with its heater control unit
Cummins is developing an even more advanced version of the HCU for 2027 engines
Cummins says it is focused on making the integration of new heater control units as seamless as possible. Features such as cybersecurity, circuit protection and lightweight components are designed to support efficient, durable system integration. The company says its aftertreatment technologies are intended to help fleets meet ultra-low NOx requirements.
Previously from Cummins Inc.
Cummins has recently published explainer content about the components behind its emissions control systems. In September 2026 it detailed how engine sensors work, from pressure and temperature to NOx monitoring, describing the sensor networks it calls the nerves and brain of an engine system and noting that onboard diagnostics rules make sensor durability a make-or-break engineering standard.
Background drawn from MotorClaw's earlier coverage of Cummins Inc.'s official releases.
Why this matters
Stricter ultra-low NOx standards, set by state and federal regulators, mean exhaust cleanup has to work even in the hardest conditions, such as cold starts and low-load operation. For fleets and buyers of diesel-powered vehicles and equipment, technologies like Cummins' heater control unit are part of how manufacturers expect to keep meeting those emissions rules.
Terms in This Story
- NOx
- Nitrogen oxides, a group of polluting gases produced during combustion that emissions regulations limit.
- aftertreatment system
- The equipment downstream of an engine's combustion that removes pollutants from the exhaust before it leaves the vehicle.
- catalyst
- A material in the exhaust system that speeds up a chemical reaction converting harmful gases into less harmful ones.
- DC/DC converter
- An electronic device that changes one direct-current voltage into another.
Summarised from the linked release; details can be imperfect — always verify against the original source.